Course Instructions

NOTE: The following pages contain a preview of the final exam. This final exam is identical to the final exam that you will take online after you purchase the course.

After you purchase the course online, you will be taken to a receipt page online which will have the following link: Click Here to Take Online Exam. You will then click on this link to take the final exam.

3 Easy Steps to Complete the Course:

1.) Read the Course PDF Below.

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Tunnel Inspection Manual Final Exam

1. This manual provides specific information for the inspection of both highway and rail transit tunnels. a. True b. False

2. As per Figure 2.8, the horseshoe tunnel shape typically exists in: a. clay b. shale c. sandstone conditions d. rock conditions

3. Regarding Ventilation Systems, tunnel ventilation systems can be categorized into ____ main types: a. one. b. five. c. three. d. four.

4. Regarding Inspection Qualifications, the inspection should be accomplished with teams consisting of a minimum of ____ individuals: a. one. b. two. c. three. d. four.

5. As per Table 3-1, the acronym PCLS stands for: a. Precast Concrete Liner Segments. b. Post-tensioned Concrete Liner Segments. c. Polymer Cast Liner Sleeve. d. Post Construction Limed Shotcrete.

6. Considering Inspection of Civil/Structural Elements, the tunnel owner should establish the frequency for up-close inspections of the tunnel structure based on the age and condition of the tunnel. a. True b. False

7. As per Table 4-1, the rating for “Excellent condition – No defects found” is: a. 9. b. 5. c. 0. d. 8.

8. Considering Inspection of Electrical Systems, the main purpose of an in-depth inspection is to verify that the electrical systems are performing as expected. a. True b. False

9. As per Table 4-5, the maximum allowable operating speed for passenger trains on class 3 track is: a. 100 km/h. b. 25 km/h. c. 140 km/h. d. 50 km/h.

10. Considering Field Data, for the tunnel structure, the documentation of severe defects should include a sketch: a. True b. False

Highway and Rail Transit Tunnel Inspection Manual

2005 Edition

U.S. Department of Transportation Federal Highway Administration Federal Transit Administration

1 | Tunnel Inspection Manua l FEDER A L HIGHWAY ADMINISTRATION EXECUTIVE SUMMARY In March of 2001, the Federal Highway Administration track systems, power systems (third rail/ catenary), and (FHWA), in conjunction with the Federal Transit signal/communications systems. Administration (FTA), engaged Gannett Fleming, Inc., to develop the first ever Tunnel Management System to benefit both highway and rail transit tunnel Fundamentals of Tunnel Inspection owners throughout the United States and Puerto As can be expected, there are basic steps that must Rico. Specifically, these federal agencies, acting as be properly accomplished for the end product of ONE DOT, set a common goal to provide uniformity the inspection to be useful to the tunnel owner and consistency in assessing the physical condition for planning purposes. These steps include making of the various tunnel components. It is commonly sure that the inspectors are qualified to properly understood that numerous tunnels in the United identify defects and make recommendations about States are more than 50 years old and are beginning their respective systems within the tunnel. Also, the to show signs of considerable deterioration, especially responsibilities of the individual inspection team due to water infiltration. In addition, it is desired that members and the tunnel owner are discussed. The next good maintenance and rehabilitation practices be section lists the equipment/tools that may be required presented that would aid tunnel owners in the repair of to perform the inspections. identified deficiencies. To accomplish these ONE DOT goals, Gannett Fleming, Inc., was tasked to produce an A section on preparation for the inspection consists of Inspection Manual, a Maintenance and Rehabilitation describing the tasks that should be completed during Manual, and a computerized database wherein all the mobilization phase of the inspection. Also, a survey inventory, inspection, and repair data could be control section is given that describes how to record collected and stored for historical purposes. the inspection results with respect to their location within the tunnel. Following that, suggested standard This manual provides specific information for the forms are presented that can be used to record the inspection of both highway and rail transit tunnels. actual structural condition codes assessed during the Although several components are similar in both inspection. types of tunnels, a few elements are specific to either highway or rail transit tunnels and are defined After the preparation section, brief sections on accordingly. The following paragraphs explain the methods of access, which describes equipment that specific subjects covered along with procedural might be necessary to reach the areas that need to be recommendations that are contained in this manual. inspected, and safety practices for both highway and rail transit tunnels are included.

Introduction Inspection Procedures – General Discussion This chapter presents a brief history of the project development and outlines the scope and contents This chapter presents recommended frequencies and of the Inspection Manual. specific defects to look for in each of the following categories: structural elements, mechanical systems, electrical systems, and other systems/appurtenances. Tunnel Construction and Systems The structural elements section includes descriptions To develop uniformity concerning certain tunnel of defects in concrete, steel, masonry, and timber. Also components and systems, this chapter was developed included in this section is a segment describing the to define those major systems and describe how they procedures that should be followed in the event that relate to both highway and rail transit tunnels. This the inspection reveals defects that require immediate chapter is broken down into four sub-chapters, which repair. Structural conditions codes are detailed on a 0 include: tunnel types, ventilation systems, lighting to 9 scale for the general condition and subsequently systems, and other systems/appurtenances. for specific tunnel segments for cut-and-cover box tunnels, soft ground tunnel liners, rock tunnel liners, The tunnel types section covers the different tunnel and timber liners. The individual tunnel segment shapes in existence, liner types that have been used, ratings are summarized in a table. the two main invert types, the various construction methods used to construct a tunnel, and the multiple The systems/appurtenances section includes general different finishes that typically exist in highway discussions on track elements, power systems (third tunnels. The ventilation and lighting system sections rail/catenary), and signal/communication systems. are self explanatory in that they cover the basic Given the complexity of these systems, only general system types and configurations. The other systems/ inspection recommendations are given for the major appurtenances section is used to explain tunnel components. systems that are present in rail transit tunnels, such as:

2 | Tunnel Inspection Manua l FEDER A L HIGHWAY ADMINISTRATION Inspection Documentation structure and any specialized testing reports that were generated during the inspection. The final chapter of this manual offers suggestions on how to properly record the results of an indepth Repair priority definitions are presented so that the inspection. The field data section describes how to individuals writing the inspection report can classify visually record the defects that are found, either on the defects based on definitions for critical, priority, pre-printed forms or through the use of tablet PC’s and routine classifications. Finally, a recommended (pen based computers) in to a database. Abbreviations outline for the inspection report is given for guidance are given for the most common defects that are as to what information should be included for the found on the tunnel structure. Also included are tunnel owners’ use in determining how to address the recommendations that are specific to the track items identified during the inspection.

CHAPTER 1: INTRODUCTION Background Scope The National Bridge Inspection Standards (NBIS) were The purpose of this manual is to provide highway and established in the early 1970s to ensure highway rail transit tunnel owners guidance for establishing structures received proper inspection using uniform procedures and practices for the inspection, documen- procedures and techniques. The NBIS address a tation, and priority classification of deficiencies for number of issues including personnel qualification, various elements that comprise an existing tunnel. It inspection frequency, and reporting of inspection is also the intent that this manual be used as part of a findings. Following the issuance of the NBIS, the comprehensive inspection and maintenance program. Federal Highway Administration (FHWA) developed The preliminary research performed indicates that a a comprehensive training course, including an majority of tunnel owners believe there is a need to inspector’s manual, designed for those individuals develop guidance for procedures for managing tunnel in the highway community responsible for bridge activities that could be readily implemented. inspection. The training course and manual covered This manual addresses inspection procedures for the the typical types of highway structures in the nation, functional aspect of the tunnel, focusing on the civil/ providing information on inspection procedures for structural, mechanical, and electrical components. The the various components of those structures. Missing manual does, however, provide brief guidance on other from the material was appropriate procedures to systems/appurtenances, such as track, traction power, employ for preparing and conducting inspections on signals, and communications, which comprise the the various features of highway tunnels. Tunnels were operational aspects of a rail transit tunnel. This brief considered unique structures and special applications guidance is only meant to provide general knowledge would be needed for them. and not in-depth inspection criteria for such systems/ Recently, the FHWA created an office specifically to appurtenances. focus on management of highway assets. This office has a major function—to work with the highway Contents community to design, develop, and implement state- To ensure consistency of definition of particular of-the-art systems for managing highway assets, elements, this manual contains several chapters that including bridges and pavements. One area of the explain the various types of elements that exist within highway needing emphasis was a management the tunnel. For example, the description of tunnel system for tunnels. Similarly, the Federal Transit components such as tunnel configuration, liner types, Administration (FTA) is responsible for providing invert types, ventilation systems, lighting systems, transit tunnel owners with a wide range of assistance, tunnel finishes and other systems/appurtenances including guidance on appropriate management (track, traction power, signals, and communications) techniques. Because of the common interest on are each provided in separate sections to assist tunnel management procedures from both agencies, tunnel owners in educating their inspectors as to the the FHWA and FTA have joined to sponsor the particular system used for the tunnel to be inspected. development of a system for highway and rail transit Furthermore, the manual provides suggested guidelines tunnels. A project to develop the system was initiated for inspection personnel qualifications and equipment in March of 2001 to include preparing an inventory to be used for performing the inspection. Since most of highway and rail transit tunnels in the U.S., an tunnels are constructed of concrete, steel, masonry, inspection manual, a manual for maintenance and and timber (to a very limited degree), this manual repair, and a computer software program for data provides extensive definitions of the types of common management. All of these products will be furnished defects that occur within these major structural to each highway and transit tunnel owner across the elements so that the inspection documentation is nation, and will be available as public domain. consistent according to the guidelines provided. FEDER A L HIGHW AY ADMINISTRATION Tunnel Inspecti on M anual | 3 The manual contains procedures for documenting the developed herein are for visual and non-destructive inspection findings. These range from identifying a methods of evaluating the tunnel elements. This particular defect (cracking, scaling, spalling, corrosion, does not preclude the lead inspector from requesting etc.) and its severity (minor, moderate, or severe) to that certain destructive means (e.g., extracting assessing the overall condition of an element within cores for determination of freeze/thaw resistance or a particular region of the tunnel. The manual is based concrete strength) be requested to aid in determining upon a condition assessment scale that varies from soundness/adequacy of the tunnel elements. “0” to “9,” with 0 being the worst condition and 9 Although this manual is produced for a hands-on, non- being the best condition. This is similar to the scale destructive evaluation of the inside face of the used for the National Bridge Inventory that is familiar tunnel structure, other state-of-the-art, non-destructive to most highway/transit tunnel owners. The length testing methods may be used in areas that require a of a tunnel segment for which these ratings will be more in-depth structural evaluation. These methods applied will vary with each tunnel and tunnel owner. may include mechanical oscillation techniques such Some tunnels have panels that are numbered between as sonic or ultrasonic measurements (more commonly particular joints, which make it easy for determining referred to as Impact-Echo), electronic techniques such the segment length over which condition assessments as georadar, and optical techniques such as infrared are to be evaluated. Other tunnel owners may choose thermography and multispectral analysis. Each of the to have the evaluation performed for a segment of a above methods has been used successfully in tunnels; tunnel, say 30 m (100 ft) or 60 m (200 ft). Regardless, however, a full understanding of the applications and the entire tunnel is to be inspected and condition limitations of each method is necessary to maximize assessments applied for all tunnel segments. their benefits. The manual will also provide guidance for the It is felt, however, that these state-of-the-art methods inspector to prioritize defects for repair and are probably only cost effective in long, rail transit rehabilitation. Although this manual proposes the use tunnels in metropolitan areas. It is assumed that these of three prioritizations for conducting repairs, namely methods will mostly supplement and not replace the critical, priority, and routine, tunnel owners can adopt hands-on, non-destructive testing methods described other prioritizations as appropriate. in this manual for many tunnel owners in the United This manual is developed for a hands-on, up-close States. inspection of the tunnel structure. The procedures

CHAPTER 2: TUNNEL CONSTRUCTION AND SYSTEMS A. TUNNEL TYPES will appear rectangular from inside, due to horizontal roadways and ceiling slabs, the outside This section describes the various types of highway and shape of the tunnel defines its type. Some tunnels rail transit tunnels. These tunnel types are described may be constructed using combinations of these by their shape, liner type, invert type, construction types due to different soil conditions along the method, and tunnel finishes. It should be noted that length of the tunnel. Another possible highway other types may exist currently or be constructed in tunnel shape that is not shown is a single box the future as new technologies become available. The with bi-directional traffic. purpose of this section is to look at the types that are

CENTERLINE CENTERLINE most commonly used in tunnel construction to help OF TUNNEL OF ROADWAY the inspector properly classify any given tunnel. As a general guideline a minimum length of 100 meters

(~300 feet) was used in defining a tunnel for inventory * ALTERNATIVE purposes. This length is primarily to exclude long * CEILING SLAB THAT PROVIDES underpasses, however other reasons for using the SPACE FOR AIR

TUNNEL WIDTH PLENUM AND tunnel classification may exist such as the presence of UTILITIES ABOVE lighting or a ventilation system, which could override HORIZONTAL CLEARANCE

the length limitation. * ALTERNATIVE

CEILING SLAB 1. Shapes THATFigure PROVIDES 2.1 – SAFETY SPACE FOR AIR

WALK HEIGHT TUNNEL CircularPLENUM AND tunnel

VERTICAL

a) Highway Tunnels CLEARANCE UTILITIES ABOVE with two traffic As shown in Figures 2.1 to 2.4, there are four lanes and one main shapes of highway tunnels – circular, safety walk. Also rectangular, horseshoe, and oval/egg. The shown is an different shapes typically relate to the method of alternative ceiling slab. construction and the ground conditions in which Invert may be solid they were constructed. Although many tunnels concrete over liner or a structural slab.

4 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION

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FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 5

Figure 2.4 – Oval/egg tunnel with three traffic lanes and two safety walks. Also shown is alternative ceiling slab.

b) Rail Transit Tunnels

Figures 2.5 to 2.9 show the typical shapes

for rail transit tunnels. As with highway

tunnels, the shape typically relates to the method/ground conditions in which they CENTERLINE OF were constructed. The shape of rail transit TUNNEL & TRACK tunnels often varies along a given rail

line. These shapes typically change at the

transition between the station structure

and the typical tunnel crosssection. However, the change in shape may also

occur between stations due to variations in TUNNEL WIDTH ground conditions.

SAFETY WALK TOP OF INVERT RAIL SLAB

Figure 2.5 – Circular tunnel with a single track and one safety walk. Invert slab is placed on top of liner.

6 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION

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FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 7

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e) Segmental Linings tunnel length, and are spaced between 750 mm (30 in) and 1,500 mm (60 in) on centers. Newer tunnels, Segmental linings are primarily used in similar to the second Hampton Roads Tunnel in conjunction with a tunnel boring machine (TBM) Virginia, provide structural reinforced concrete slabs in soft ground conditions. The prefabricated that span the required distance between supports. lining segments are erected within the cylindrical tail shield of the TBM. These prefabricated It is necessary to determine the type of roadway slab segments can be made of steel, concrete, or cast used in a given tunnel because a more extensive iron and are usually bolted together to compress inspection is required for a structural slab than gaskets for preventing water penetration. for a slab-on-grade. Examples of structural slabs in common tunnel shapes are shown in Figures 2.10 to f) Placed Concrete 2.12. Placed concrete linings are usually the final

linings that are installed over any of the previous initial stabilization methods. They can be used as a thin cover layer over the primary liner to

provide a finished surface within the tunnel or to sandwich a waterproofing membrane. They can be reinforced or unreinforced. They can be designed as a non-structural finish element or as

the main structural support for the tunnel. g) Slurry Walls

Slurry wall construction types vary, but typically

they consist of excavating a trench that matches CENTERLINE OF TUNNEL the proposed wall profile. This trench is

continually kept full with a drilling fluid during

excavation, which stabilizes the sidewalls. Then

a reinforcing cage is lowered into the slurry

or soldier piles are driven at a predetermined EXHAUST AIR DUCT

interval and finally tremie concrete is placed

into the excavation, which displaces the drilling

fluid. This procedure is repeated in specified panel

lengths, which are separated with watertight

joints.

3. Invert Types

The invert of a tunnel is the slab on which the CENTERLINE OF roadway or track bed is supported. There are two ROADWAY

STRUCTURAL main methods for supporting the roadway or SLAB

track bed; one is by placing the roadway or track

bed directly on grade at the bottom of the tunnel

structure, and the other is to span the roadway

between sidewalls to provide space under the

roadway for ventilation and utilities. The first FRESH AIR DUCT method is used in most rail transit tunnels because their ventilation systems rarely use supply ductwork under the slab. This method is also employed in many highway tunnels over land where ventilation is supplied from above the roadway level. Figure 2.10 – Circular tunnel with a structural slab The second method is commonly found in circular that provides space for an air plenum below. highway tunnels that must provide a horizontal roadway surface that is wide enough for at least two lanes of traffic and therefore the roadway slab is suspended off the tunnel bottom a particular distance. The void is then used for a ventilation plenum and other utilities. The roadway slab in many of the older highway tunnels in New York City is supported by placing structural steel beams, encased in concrete, that span transversely to the FEDER A L HIGHW AY ADMINISTRATION Tunnel Inspecti on M anual | 9 CENTERLINE OF CENTERLINE OF TUNNEL TUNNEL

EXHAUST AIR DUCT EXHAUST AIR DUCT

CENTERLINE OF ROADWAY CENTERLINE OF ROADWAY

STRUCTURAL STRUCTURAL SLAB SLAB

FRESH AIR DUCT

Figure 2.11 – Single box tunnel with a structural slab that provides space for an air plenum below. Figure 2.12 – Horseshoe tunnel with a structural slab that provides space for an air plenum below.

4. Construction Methods systems to construct the walls of a cut and cover tunnel. As mentioned previously, the shape of the tunnel is largely dependent on the method used to construct b) Shield Driven the tunnel. Table 2.1 lists the six main methods used for tunnel construction with the shape that typically This method involves pushing a shield into the results. Brief descriptions of the construction soft ground ahead. The material inside the shield methods follow: is removed and a lining system is constructed before the shield is advanced further. a) Cut and Cover c) Bored This method involves excavating an open trench in which the tunnel is constructed to the design This method refers to using a mechanical TBM finish elevation and subsequently covered with in which the full face of the tunnel cross section various compacted earthen materials and soils. is excavated at one time using a variety of Certain variations of this method include using cutting tools that depend on ground conditions piles and lagging, tie back anchors or slurry wall (soft ground or rock). The TBM is designed to

Circular Horseshoe Rectangular Cut and Cover X Shield Driven X Bored X Drill and Blast X X Immersed Tube X X Sequential Excavation X Jacked Tunnels X X Table 2.1 – Construction Methods

10 | Tunnel Inspection Manual FEDERAL HIGHWAY ADMINISTRATION support the adjacent soil until temporary (and • Be fire resistant subsequently permanent) linings are installed. • Be precluded from producing toxic fumes during a fire d) Drill and Blast • Be able to attenuate noise An alternative to using a TBM in rock situations • Be easy to clean. would be to manually drill and blast the rock A brief description of the typical types of tunnel and remove it using conventional conveyor finishes that exist in highway tunnels is given techniques. This method was commonly used below. Transit tunnels often do not have an interior for older tunnels and is still used when it is finish because the public is not exposed to the determined cost effective or in difficult ground tunnel lining except as the tunnel approaches the conditions. stations or portals. e) Immersed Tube a) Ceramic Tile When a canal, channel, river, etc. needs to be This type of tunnel finish is the most widely used by crossed, this method is often used. A trench tunnel owners. Tunnels with a concrete or shotcrete is dug at the water bottom and prefabricated inner lining are conducive to tile placement tunnel segments are made water tight and sunken because of their smooth surface. Ceramic tiles are into position where they are connected to the extremely fire resistant, economical, easily cleaned, other segments. Afterwards, the trench may be and good reflectors of light due to the smooth, backfilled with earth to cover and protect the glazed exterior finish. They are not, however, good tunnel from the water borne traffic, e.g., ships, sound attenuators, which in new tunnels has been barges, and boats. addressed through other means. Typically, tiles are f) Sequential Excavation Method (SEM) 106 mm (4 ¼ in) square and are available in a wide variety of colors. They differ from conventional Soil in certain tunnels may have sufficient ceramic tile in that they require a more secure strength such that excavation of the soil face connection to the tunnel lining to prevent the tiles by equipment in small increments is possible from falling onto the roadway below. Even with without direct support. This excavation method a more secure connection, tiles may need to be is called the sequential excavation method. Once replaced eventually because of normal deterioration. excavated, the soil face is then supported using Additional tiles are typically purchased at the time shotcrete and the excavation is continued for of original construction since they are specifically the next segment. The cohesion of the rock or made for that tunnel. The additional amount soil can be increased by injecting grouts into the purchased can be up to 10 percent of the total tiled ground prior to excavation of that segment. surface. g) Jacked Tunnels b) Porcelain-Enameled Metal Panels The method of jacking a large tunnel underneath Porcelain enamel is a combination of glass and certain obstructions (highways, buildings, rail inorganic color oxides that are fused to metal lines, etc.) that prohibit the use of typical cut- under extremely high temperatures. This method is and-cover techniques for shallow tunnels has used to coat most home appliances. The Porcelain been used successfully in recent years. This Enamel Institute (PEI) has established guidelines for method is considered when the obstruction the performance of porcelain enamel through the cannot be moved or temporarily disturbed. First following publications: jacking pits are constructed. Then tunnel sections are constructed in the jacking pit and forced Appearance Properties (PEI 501) by large hydraulic jacks into the soft ground, Mechanical and Physical Properties (PEI 502) which is systematically removed in front of the Resistance to Corrosion (PEI 503) encroaching tunnel section. Sometimes if the High Temperature Properties (PEI 504) soil above the proposed tunnel is poor then it is Electrical Properties (PEI 505). stabilized through various means such as grouting Porcelain enamel is typically applied to either cold- or freezing. formed steel panels or extruded aluminum 5. Tunnel Finishes panels. For ceilings, the panels are often filled with a lightweight concrete; for walls, fiberglass boards The interior finish of a tunnel is very important to are frequently used. The attributes of porcelain- the overall tunnel function. The finishes must meet enameled panels are similar to those for ceramic the following standards to ensure tunnel safety and tile previously discussed; they are durable, easily ease of maintenance: washed, reflective, and come in a variety of colors. • Be designed to enhance tunnel lighting and As with ceramic tile, these panels are not good for visibility sound attenuation.

FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 11 c) Epoxy-Coated Concrete five main types or any combination of these five2. Epoxy coatings have been used on many The five types are as follows: tunnels during construction to reduce • Natural Ventilation costs. Durable paints have also been used. • Longitudinal Ventilation The epoxy is a thermosetting resin that is • Semi-Transverse Ventilation chemically formulated for its toughness, strong • Full-Transverse Ventilation adhesion, reflective ability, and low shrinkage. • Single-Point Extraction. Experience has shown that these coatings do not withstand the harsh tunnel environmental It should be noted that ventilation systems are conditions as well as the others, resulting in more applicable to highway tunnels due to high the need to repair or rehabilitate more often. concentration of contaminants. Rail transit tunnels often have ventilation systems in the d) Miscellaneous Finishes stations or at intermediate fan shafts, but during There are a variety of other finishes that can be normal operations rely mainly on the piston used on the walls or ceilings of tunnels. Some of effect of the train pushing air through the tunnel these finishes are becoming more popular due to remove stagnant air. Many rail transit tunnels to their improved sound absorptive properties, have emergency mechanical ventilation that only ease of replacement, and ability to capitalize on works in the event of a fire. For further information the benefits of some of the materials mentioned on tunnel ventilation systems refer to NFPA 502 above. Some of the systems are listed below: (National Fire Protection Association10). (1) Coated Cementboard Panels a) Natural Ventilation These panels are not in wide use in American A naturally ventilated tunnel is as simple as the tunnels at this time, but they offer a name implies. The movement of air is controlled lightweight, fiber-reinforced cementboard by meteorological conditions and the piston that is coated with baked enamel. effect created by moving traffic pushing the stale air through the tunnel. This effect is minimized (2) Precast Concrete Panels when bi-directional traffic is present. The This type of panel is often used as an meteorological conditions include elevation and alternative to metal panels; however, a temperature differences between the two portals, combination of the two is also possible and wind blowing into the tunnel. Figure 2.13 where the metal panel is applied as a veneer. shows a typical profile of a naturally ventilated Generally ceramic tile is cast into the tunnel. Another configuration would be to add underside of the panel as the final finish. a center shaft that allows for one more portal by which air can enter or exit the tunnel. Many (3) Metal Tiles naturally ventilated tunnels over 180 m (600 ft) This tile system is uncommon, but has in length have mechanical fans installed for use been used successfully in certain tunnel during a fire emergency. applications. Metal tiles are coated with b) Longitudinal Ventilation porcelain enamel and are set in mortar similarly to ceramic tile. Longitudinal ventilation is similar to natural ventilation with the addition of mechanical fans, either in the portal buildings, the center shaft,

B. VENTILATION SYSTEMS or mounted inside the tunnel. Longitudinal ventilation is often used inside rectangular- 1. Types shaped tunnels that do not have the extra space Tunnel ventilation systems can be categorized into above the ceiling or below the roadway for

TUNNEL LENGTH

AIR FLOW OF TRAFFIC AIR FLOW FLOW

Figure 2.13 – Natural Ventilation

12 | Tunnel Inspection Manual FEDERAL HIGHWAY ADMINISTRATION

FLOW AIR FLOW AIR FLOW AIR FLOW AIR

A IR CROSS

FLOW FLOW AIR

FAN SECTION FAN FLOW AIR FAN FAN (TYP)

(TYP) FAN

Figure

FLOW FLOW 2.14 FLOW FLOW TUNNEL TUNNEL

–

OF OF Longitudinal TUNNEL TUNNEL OF

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SUPPLY AIR Figure 2.15 – Semi-Transverse Ventilation

FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 13

(bi either change or fans be last plenum, of is exhaust an half tu One are transverse exhaust an of example and one system one with or ceiling ductwork air flues added ductwork. does mechanical Semi Semi tunnels. configurations out can through air of replace; the ductwork. | | FAN

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2. Equipment (2) Fan Drives a) Fans A motor can be connected to the fan either directly or indirectly. Direct drives are where (1) Axial the fan is on the same shaft as the motor. There are two main types of axial fans—tube Indirect drives allow for flexibility in motor axial fans and vane axial fans. Both types location and are connected to the impellor move air parallel to the impellor shaft, shaft by belts, chains, or gears. The type of but the difference between the two is the drive used can also induce speed variability addition of guide vanes on one or both sides for the ventilation system. of the impellor for the vane axial fans. These (3) Sound Attenuators additional vanes allow the fan to deliver pressures that are approximately four times Some tunnel exhaust systems are located in that of a typical tube axial fan. The two most regions that require the noise generated by common uses of axial fans are to mount them the fans to be reduced. This can be achieved horizontally on the tunnel ceiling at given by installing cylindrical or rectangular intervals along the tunnel or to mount them attenuators either mounted directly to the fan vertically within a ventilation shaft that exits or within ductwork along the system. to the surface. (4) Dampers (2) Centrifugal Objects used to control the flow of air within This type of fan outlets the air in a direction the ductwork are considered dampers. They that is 90 degrees to the direction at which are typically used in a full open or full closed air is obtained. Air enters parallel to the shaft position, but can also be operated at some of the blades and exits perpendicular to that. position in between to regulate flow or For tunnel applications, centrifugal fans can pressure within the system. either be backward-curved or airfoil-bladed.

Centrifugal fans are predominantly located C. LIGHTING SYSTEMS within ventilation or portal buildings and are connected to supply or exhaust ductwork. 1. Types They are commonly selected over axial fans due to their higher efficiency with less a) Highway Tunnels horsepower required and are therefore less expensive to operate. There are various light sources that are used in tunnels to make up the tunnel lighting systems. b) Supplemental Equipment These include fluorescent, high-pressure sodium, (1) Motors low-pressure sodium, metal halide, and pipe lighting, which is a system that may use one Electric motors are typically used to drive the of the preceding light source types. Systems are fans. They can be operated at either constant chosen based on their life- cycle costs and the or variable speeds depending on the type of motor. According to the National Electric Manufacturers Association (NEMA), motors should be able to withstand a voltage and frequency adjustment of +/- 10 percent.

Tube Axial Fan Vane Axial Fan

Figure 2.17 – Axial Fans Figure 2.18 – Centrifugal

FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 15 amount of light that is required for nighttime unite the abutting end of contiguous bolted rails. and daytime illumination. Shorter tunnels will c) Fasteners/Bolts/Spikes require less daytime lighting due to the effect of light entering the portals on both ends, whereas These fasteners include a spike, bolt, or another longer tunnels will require extensive lighting mechanical device used to tie the rail to the for both nighttime and daytime conditions. In crossties. conjunction with the lighting system, a highly reflective surface on the walls and ceiling, such as d) Tie Plates tile or metal panels, may be used. Tie plates are rolled steel plates or a rubberized Fluorescent lights typically line the entire material designed to protect the timber crosstie roadway tunnel length to provide the from localized damage under the rails by appropriate amount of light. At the ends of the distributing the wheel loads over a larger area. roadway tunnel, low-pressure sodium lamps or They assist in holding the rails to gage, tilt the highpressure sodium lamps are often combined rails inward to help counteract the outward thrust with the fluorescent lights to provide higher of wheel loads, and provide a more desirable visibility when drivers’ eyes are adjusting to the positioning of the wheel bearing area on the rail decrease in natural light. The transition length head. of tunnel required for having a higher lighting capacity varies from tunnel to tunnel and e) Crossties depends on which code the designer uses. Crossties are usually sawn solid timber, but may Both high-pressure sodium lamps and metal be made of precast reinforced concrete or fiber halide lamps are also typically used to line the reinforced plastic. The many functions of a entire length of roadway tunnels. In addition, crosstie are to: pipe lighting, usually consisting of high-pressure sodium or metal halide lamps and longitudinal • Support vertical rail loads due to train weight. acrylic tubes on each side of the lamps, are used • Distribute those loads over a wide area of to disperse light uniformly along the tunnel supporting material. length. • Hold fasteners that can resist rail rotation due to b) Rail Transit Tunnels laterally imposed loads. • Maintain a fixed distance between the two rails Rail transit tunnels are similar to highway making up a track. tunnels in that they should provide sufficient • Help keep the two rails at the correct relative light for train operators to properly adjust from elevation. the bright portal or station conditions to the • Anchor the rails against both lateral and darker conditions of the tunnel. Therefore, a longitudinal movement by embedment in the certain length of brighter lights is necessary at ballast. the entrances to the tunnels. The individual • Provide a convenient system for adjusting the tunnel owners usually stipulate the required vertical profile of the track. level of lighting within the tunnel. However, as a minimum, light levels should be of such a f) Ballast magnitude that inspectors or workers at track level could clearly see the track elements without Ballast is a coarse granular material forming a using flashlights. bed for ties, usually rocks. The ballast is used to transmit and distribute the load of the track

and railroad rolling equipment to the sub-grade; D. OTHER SYSTEMS/APPURTENANCES restrain the track laterally, longitudinally, and vertically under dynamic loads imposed by 1. Track railroad rolling equipment and thermal stresses exerted by the rails; provide adequate drainage for The track system contains the following critical the track; and maintain proper cross-level surface components: and alignment. a) Rail g) Plinth Pads The rail is a rolled, steel-shape portion of the track to be laid end-to-end in two parallel lines Plinth pads are concrete support pads or pedestals that the train or vehicle’s wheels ride atop. that are fastened directly to the concrete invert. These pads are placed at close intervals and b) Rail Joints permit the rail to span directly from one pad to Rail joints are mechanical fastenings designed to another.

16 | Tunnel Inspection Manual FEDERAL HIGHWAY ADMINISTRATION BRACKET

BRACKET Figure 2.19 – Typical Third Rail Power System

DISCONNECT (Note: Dimensions indicate minimum clearance SWITCH 750 VDC requirements)

578 mm (23 1/8 in)

BRACKET

650 mm (26 in)

STEEL CONTACT

RAIL INSULATOR TIE

87 mm (3 1/2 in) BETWEEN BOARD AND RAIL

PROTECTION BOARD

BUTTON HEAD PIN WITH COTTER KEY, THIRD RAIL TYPICAL

FIBERGLASS STRAIN INSULATOR

LAG SCREW WITH GIMLET ANCHOR STRAP, POINT, GALVANIZED WOOD TIE THIRD RAIL Figure 2.20 – Typical Third Rail Insulated Anchor Arm

2. Power (Third Rail/Catenary) at the midpoint of each long section, with a maximum length for any section limited to a) Third Rail Power System 1.6 km (1 mile). A third rail power system will consist of the b) Catenary Power System elements listed below and will typically be arranged as shown in Figures 2.19 and 2.20 The catenary system is an overhead power (1) Steel Contact Rail system whereby the rail transit cars are powered by means of contact between the pantographs Steel contact rail is the rail that carries power atop the rail car and the catenary wire. A typical for electric rail cars through the tunnel and is catenary system may consist of some or all of placed parallel to the other two standard rails. the following components: balance weights, (2) Contact Rail Insulators yoke plates, steady arms, insulators, hangers, jumpers, safety assemblies, pull-off arrangements, Contact rail insulators are made either of back guys and anchors, underbridge assemblies, porcelain or fiberglass and are to be installed contact wires, clamped electrical connectors, at each supporting bracket location. messenger supports, registration assemblies, (3) Protection Board overlaps, section insulators, phase breaks, and section disconnects. For tunnel catenary systems, Protection boards are placed above the steel some of the above components are not necessary contact rail to “protect” personnel from or are modified in their use. This is particularly making direct contact with this rail. These true for the methods of support in that the boards are typically made of fiberglass or catenary system is supported directly from the timber. tunnel structure instead of from poles with guy (4) Protection Board Brackets wires. Protection board brackets are mounted on Since the methods used to support a catenary either timber ties or concrete ties/base and system within a tunnel can vary, a detailed are used to support the protection board at a description of the individual components is not distance above the steel contact rail. given in this section. For inspection purposes, Chapter 4, Section D, Part 2 provides inspection (5) Third Rail Insulated Anchor Arms procedures for various components listed above Third rail insulated anchor arms are located that may exist in a tunnel catenary system. FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 17 3. Signal/Communication Systems b) Communication System a) Signal System The communication system consists of all devices that allow communication from or within a The signal system is a complex assortment of tunnel. Examples of these systems would be electrical and mechanical instruments that work emergency phones that are located periodically together to provide direction for the individual along a highway tunnel and radios by which trains within a transit system. A typical signal train controllers correspond with each other system may consist of some or all of the following and central operations. The specific components components: signals, signal cases, relay rooms, included in a communication system include the switch machines, switch circuit controllers, local phones and radios, as well as any cables, wires, or cables, express cables, signal power cables, duct other equipment that is needed to transport the banks, messenger systems, pull boxes, cable messages. vaults, transformers, disconnects, and local control facilities.

CHAPTER 3: FUNDAMENTALS OF TUNNEL CONSTRUCTION A. INSPECTOR QUALIFICATIONS b) Team Member(s) The inspection should be accomplished with teams • Be trained in general tunnel inspection consisting of a minimum of two individuals; all team requirements. members should meet certain minimum qualifications • Have a minimum of one year inspection as defined below. Aside from these general experience in concrete, steel, timber, and qualifications and the specific qualifications listed for masonry structures. each discipline, a tunnel owner may require that all 2. Mechanical tunnel inspection team members be certified to ensure that these qualifications are met. This certification a) Team Leader would need to be performed by the tunnel owner, since currently there is no national tunnel inspection • Be a registered professional engineer or certification program. These inspection team members • Have design experience or be familiar with the are classified as a Team Leader and Team Member(s). type of mechanical systems installed in the All individuals who will perform inspection work tunnel. Examples of these systems are, but not should be knowledgeable of tunnel components and limited to: understand how they function. The inspection team • Tunnel Ventilation should meet the following general qualifications: • Air Conditioning • Heating • Be able to climb and/or use equipment to access • Controls the higher regions of the structures. • Plumbing • Be able to evaluate and determine types of • Tunnel Drainage Systems (e.g., sump equipment or testing required to fully define a pumps) deficiency. • Fire Protection • Be able to print legibly and to draw • Wells/Septic. understandable sketches. • Have a minimum of three years inspection • Be able to read and interpret drawings. experience with the ability to evaluate the • Be able to use tablet PC’s for data collection. physical condition as well as the operational Specific qualifications of the Team Leader and Team condition of equipment. Member(s) for the various components to be inspected • Be aware of applicable codes and guidelines include: for tunnel construction and operation pertaining to mechanical features. 1. Civil/Structural b) Team Member(s) a) Team Leader • Be trained in general inspection requirements.

• Be a registered professional engineer or • Have a minimum of one year inspection

• Have design experience in tunnels using the experience with mechanical and plumbing same materials and systems. • Have a minimum of five years inspection experience with the ability to identify and 3. Electrical evaluate defects that pose a threat to the a) Team Leader integrity of a structural member. • Be able to assess the degree of deterioration for • Be a registered professional engineer or concrete, steel, masonry, and timber members. • Have design experience or be familiar with the 18 | Tunnel Inspection Manual FEDERAL HIGHWAY ADMINISTRATION type of electrical systems installed in the tunnel. stations, and vehicle maintenance and Examples of these systems include, but are not storage areas; and for life safety from fire in limited to: fixed guideway transit stations, trainways, • Power Distribution vehicles, and outdoor vehicle maintenance • Emergency Power and storage areas. • Lighting • IES LM-50 – Illuminating Engineering Society, • Fire Detection Lighting Measurements–50 – provides a • Communications. uniform test procedure for determining, measuring, and reporting the illuminance • Have a minimum of three years inspection and luminance characteristics of roadway experience with the ability to evaluate the lighting installations. physical condition as well as the operational • IES RP-22 – Illuminating Engineering Society, condition of the electrical systems and Recommended Practices–22 – provides equipment. information to assist engineers and • Be aware of applicable codes and guidelines for designers in determining lighting needs, tunnel construction and operation, including, recommending solutions, and evaluating but not limited to the following: resulting visibility at vehicular tunnel • NETA MTS 1 –National Electrical Testing approaches and interiors. Association, Maintenance Testing Specifications – developed for those responsible for the b) Team Member(s) continued operation of existing electrical • Be trained in general electrical inspection systems and equipment to guide them in requirements. specifying and performing the necessary tests to ensure that these systems and • Have a minimum of one year inspection apparatus perform satisfactorily, minimizing experience with electrical systems. downtime and maximizing life expectancy. c) Special Testing Agencies • NFPA 70 – National Fire Protection Association 70 – covers installations of electric The use of special testing agencies is required for conductors and equipment within or testing the power distribution and fire protection on public and private buildings or other systems. Such agencies shall meet the following structures, installations of conductors and requirements: equipment that connect to the supply of • Be a member of The International Electrical electricity, installations of other outside Testing Association (NETA) or meet all of the conductors and equipment on the premises, following qualifications: and installations of optical fiber cables and • Be nationally recognized as an electrical testing raceways. laboratory. • NFPA 70B – National Fire Protection • Be regularly engaged in the testing of electrical Association 70B – recommended practice systems and equipment for the past five years. for electrical equipment maintenance • Have at least one professional engineer on staff for industrial-type electrical systems and that is licensed in the state where the work is equipment, but is not intended to duplicate being done. or supersede instructions that electrical • Have in house or lease sufficient calibrated manufacturers normally provide. equipment to do the testing required. • NFPA 70E – National Fire Protection • Have a means to trace all test instrument Association 70E – addresses those electrical calibration to The National Bureau of Standards. safety requirements for employee workplaces that are necessary for the 4. Track, Third Rail, Catenary, Signals, and practical safeguarding of employees in their Communications pursuit of gainful employment. a) Team Leader • NFPA 72 – National Fire Protection Association 72 – national fire alarm code that covers • Be a registered professional engineer or the application, installation, location, • Have design experience in the system performance, and maintenance of fire alarm components being inspected. systems and their components. • Have a minimum of three years inspection • NFPA 130 – National Fire Protection experience with the ability to identify and Association 130 – covers fire protection evaluate the condition of the components being requirements for passenger rail, inspected. underground, surface, and elevated • Be familiar with specialized testing equipment fixed guideway transit systems including to assess a particular component’s operational trainways, vehicles, fixed guideway transit viability.

FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 19 b) Team Member(s) • Ladders - Used in lieu of a lifting system to access areas not visible from the ground. • Be trained in general inspection requirements. • Light Meter - Used to measure the brightness in • Have a minimum of one year inspection the tunnel. experience with track, third rail, catenary, • Halogen Lights - Used where tunnel lighting is signals and communications systems. inadequate during inspection. • Pencil • Plumb Bob - Used to check plumbness of columns B. RESPONSIBILITIES and wall faces. • Pocket Knife - Used to examine loose material and Each member of the inspection team must fulfill other items. certain duties for work to be accomplished in an • Sample Bottles - Used to obtain liquid samples. efficient manner. The Team Leader is responsible for • Scraper - Used to determine extent of corrosion coordination with appropriate tunnel and supervisory and concrete deterioration. staff for access into the tunnels, for scheduling • Screw Driver - Used to probe weep holes to check equipment, for determining the degree of inspection for clogs. required, for evaluating all deficiencies, for ensuring • Wire Brush or Brooms - Used to clean debris from that all inspection forms are thoroughly completed surfaces to be inspected. and legible (if using paper forms), and for notifying • Tablet PC - Used to take notes or draw sketches appropriate tunnel staff of any potentially dangerous onto screens that would be synonymous with condition. The other Team Member will assist the paper forms. team leader in the inspection. Such duties may include • Tapes performing portions of the inspection, carrying the • Pocket Tapes and Folding Rules - Used to equipment and inspection forms, taking photographs, measure dimensions of defects. and making sketches. • 30 m (100 ft) Tape (Non Metallic) - Used to The tunnel owner is responsible for closing down the measure anything beyond the reach of pocket tunnel for inspection access and for responding to any tapes and folding rules. critical actions that are identified by the inspectors. Safety equipment meeting the most current OSHA

Standards should be available for the inspection team’s C. EQUIPMENT/TOOLS use and may include: • Appropriate devices for traffic control Below is a suggested list of equipment and tools • First aid kit commonly used for tunnel inspections: • Flashlights • Aerial Bucket Truck or High Lift - Used to lift the • Hardhats inspector to areas inaccessible by foot or ladders. • Leather work gloves • Hi-Rail Vehicle - Used atop the track to gain access • Appropriate safety vests to the rail transit tunnel structure or catenary • Protective eye wear power system. The tunnel owner may supply such • Knee pads vehicles. • Safety belts or harnesses • Awl/Boring Tool - Used to determine extent of • Work boots deterioration in timber. • Protective breathing masks if soot and dirt buildup • Calipers - Used to measure steel plate thicknesses. is prevalent on the tunnel surfaces • Camera (35mm or digital) with Flash - Used to take • Air quality monitoring equipment. photographs for documentation of the inspection. For the confined spaces, the appropriate equipment • Chalk, Keel, or Markers - Used to make reference designated by the field safety officer should be marks on tunnel surfaces. employed. This equipment includes respirators, tie off • Chipping Hammer - Used to sound concrete (see ropes, radios, and instruments to measure gas levels. It Chapter 4, Section A, Part 2 – What to Look For). is especially important to monitor gas levels in areas of • Clip Board - Used to take notes and fill out paper known ground contamination by deleterious materials. inspection forms during the inspection. • Crack Comparator Gauge - Used to measure crack widths in inches. D. PREPARATION • D – Meter - Used to measure the thickness of steel. • Extension Cord - Used to get electricity to 1. Mobilization inspection area. • Field Forms - Used to document the findings, take Prior to conducting tunnel inspections, a notes, and draw sketches for the various structures. mobilization period of planning and organizing for • Flashlights - Used in dark areas to help see during the inspection is a must for the inspection to be inspection. performed as efficiently as possible.

20 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION

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FEDERAL 2.

of each panel can be established and

a defect can be located relative to its

distance from either end of the panel, 12 which can subsequently be converted

into a specific station or distance from 11 1

the end of the tunnel.

In addition to locating a defect by panel

number and station, it is necessary to

note the defect’s position within the 10 2

tunnel cross-section. Figures 3.1 to

3.5 show a typical tunnel layout plan

along with the designations for typical

tunnel cross-sections. Defects in circular

tunnels without air ducts or structural

slabs can be located using a clock system 9 3 with 12: 00 being at the top. Horseshoe, rectangular, and other circular tunnels can be broken down into the cross- sectional elements that are shown on the following pages.

3. Inspection Forms 8 4

To properly gather and record structural

inspection data for historical purposes,

it is necessary to develop forms that are clearly understood and easily

entered into a database. These forms can be on pre-printed sheets and then Table 3.2 - Circular Tunnel Clock System Designations scanned into the database or transferred

manually. Another option would be to make use of tablet PC’s, which can be pre-programmed to correspond to the

main database. This option allows the UNDERSIDE OF ROOF data to be downloaded directly into the structural database for future use. EXHAUST AIR DUCT The forms to be used fall into two TOP OF CEILING SLAB main categories: documentation UNDERSIDE OF CEILING SLAB forms and defect location forms. The documentation forms are discussed in

this section along with examples of RIGHT WALL LEFT WALL OR COLUMNS forms to be used for both highway and OR COLUMNS

rail transit tunnels. Examples of the ROADWAY

defect location forms that apply to the

components of main tunnel segments or

panels as well as auxiliary spaces such as TOP OF INVERT

portal buildings, control rooms, stations,

etc., are provided in Chapter 5, Section A. UNDERSIDE OF INVERT

LEFT RIGHT Below are general instructions for proper WALL WALL FRESH AIR DUCT completion of the subsequent example

documentation forms: BOTTOM OF PLENUM a) Highway Forms (1) Condition Code Form

T unnel Nam e: Enter the name Table 3.3 - Circular Tunnel Label System Designations typically assigned to the tunnel. Begin Station: Enter the beginning station of the tunnel

22 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION

segment for which this form is being completed (e.g.,

Sta. 70+00.00).

End Station: Enter the ending station of the tunnel

segment for which this form is being completed (e.g., Sta. 72+00.00).

UNDERSIDE OF ROOF Panel Num ber: If present, enter the predetermined

LEFT EXHAUST AIR DUCT RIGHT panel number for the segment for which this form is WALL WALL being completed (e.g., 101). TOP OF CEILING SLAB

Year Built: Enter the year during which construction

UNDERSIDE OF CEILING SLAB of the tunnel was completed.

Liner Type: Enter the appropriate acronym from Table

3.1. LEFT WALL RIGHT WALL

OR COLUMNS OR COLUMNS ROADWAY Date of Inspection: Enter the month, day, and year the inspection is performed.

Acronym Description UR Unlined Rock TOP OF INVERT CIPNR Cast-In-Place Concrete,

UNDERSIDE OF INVERT No Reinforcement RIGHT LEFT FRESH AIR DUCT CIPR Cast-In-Place Concrete, Reinforced WALL WALL SG Shotcrete/Gunite

BOTTOM OF PLENUM PCLS Precast Concrete Liner Segments

SILP Steel/Iron Liner Plate

Table 3.4 - Rectangular Tunnel Label System M Masonry Designations T Timber SCB Steel Columns and Beams, Jackarches

RMPS Rock-fall Mesh Pinned to Surface

UNDERSIDE OF ROOF Table 3.1 – Liner Type Acronyms

EXHAUST AIR DUCT Inspector(s): Enter the inspector(s) first initial and last LEFT RIGHT WALL WALL name.

TOP OF CEILING SLAB Condition Codes: Assign each element a numerical rating in accordance with the rating schedules given UNDERSIDE OF CEILING SLAB in Chapter 4, Section A, Part 4. Enter a dash (-) for all elements that are not present in the tunnel segment.

LEFT WALL RIGHT WALL Com ments: OR COLUMNS ROADWAY OR COLUMNS Add any pertinent comments as necessary

for properly explaining the tunnel segment’s condition codes.

(2) Supplemental Tunnel Segment Sketches TOP OF INVERT

T unnel Name: Enter the name typically assigned to

UNDERSIDE OF INVERT the tunnel.

LEFT RIGHT WALL WALL Begin Station: Enter the beginning station of the FRESH AIR DUCT tunnel segment for which this form is being completed

(e.g., Sta. 70+00.00). BOTTOM OF PLENUM End Station: Enter the ending station of the tunnel segment for which this form is being completed (e.g., Table 3.5 - Horseshoe Tunnel Label System Sta. 72+00.00). Designations Panel Num ber: If present, enter the predetermined panel number for the segment for which this form is being completed (e.g. 101).

FEDER A L HIGHW AY ADMINISTRATION Tunnel Inspectio n Manual | 23 Year Built: Enter the year during which station (subway or ground) that is next along construction of the tunnel was completed. direction of train traffic. Liner Type: Enter the appropriate acronym Nam e of Station Behind: Enter name of from Table 3.1. station (subway or ground) that is next in opposite direction of train traffic. Date of Inspection: Enter the month, day, and year the inspection is performed. Begin Station: Enter the beginning station of the tunnel segment for which this form is Inspector(s): Enter the inspector(s) first initial being completed (e.g., Sta. 70+00.00). and last name. End Station: Enter the ending station of the Sketches: Provide detailed sketches of defects tunnel segment for which this form is being found in areas of the tunnel or auxiliary spaces completed (e.g., Sta. 72+00.00). that is not covered by the standard forms that are provided in Chapter 5, Section A. Panel Num ber: If present, enter the predetermined panel number for the segment (3) Tunnel Segment Photo Log Sheet for which this form is being completed (e.g., T unnel Nam e: Enter the name typically 101). assigned to the tunnel. Year Built: Enter the year during which Begin Station: Enter the beginning station construction of the tunnel was completed. of the tunnel segment for which this form is Liner Type: being completed (e.g., Sta. 70+00.00). Enter the appropriate acronym from Table 3.1. End Station: Enter the ending station of the tunnel segment for which this form is being Date of Inspection: Enter the month, day, completed (e.g., Sta. 72+00.00). and year the inspection is performed. Panel Num ber: If present, enter the Inspector(s): Enter the inspector(s) first initial predetermined panel number for the segment and last name. for which this form is being completed (e.g., Condition Codes: Assign each element a 101). numerical rating in accordance with the Year Built: Enter the year during which rating schedules given in Chapter 4, Section construction of the tunnel was completed. A, Part 4. Enter a dash (-) for all elements that are not present in the tunnel segment. Liner Type: Enter the appropriate acronym from Table 3.1. Com ments: Add any pertinent comments as necessary for properly explaining the tunnel Date of Inspection: Enter the month, day, segment’s condition codes. and year the inspection is performed. (2) Supplemental Tunnel Segment Sketches Inspector(s): Enter the inspector(s) first initial and last name. Line: Enter the given name of the system line that is being inspected (e.g., A, Blue, Market Photos: Provide relevant information for Street, etc.). any photos that are taken within that tunnel segment. Include as much detail as possible T rack: Enter directional description of track within the description section. It would be being inspected (e.g., inbound, outbound, helpful to take photographs of the same north, east, south, west, etc.). conditions or defects as previous inspections, so that the rate of deterioration can be Nam e of Station Ahead: Enter name of ascertained. station (subway or ground) that is next along direction of train traffic. b) Rail Transit Forms Nam e of Station Behind: Enter name of (1) Condition Code Form station (subway or ground) that is next in Line: Enter the given name of the system line opposite direction of train traffic. that is being inspected (e.g., A, Blue, Market Begin Station: Enter the beginning station Street, etc.). of the tunnel segment for which this form is T rack: Enter directional description of track being completed (e.g., Sta. 70+00.00). being inspected (e.g., inbound, outbound, End Station: Enter the ending station of the north, east, south, west, etc.). tunnel segment for which this form is being Name of Station Ahead: Enter name of completed (e.g., Sta. 72+00.00).

24 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION Panel Number: If present, enter the predeter- opposite direction of train traffic. mined panel number for the segment for Begin Station: Enter the beginning station which this form is being completed (e.g., 101). of the tunnel segment for which this form is Year Built: Enter the year during which being completed (e.g., Sta. 70+00.00). construction of the tunnel was completed. End Station: Enter the ending station of the Liner Type: Enter the appropriate acronym tunnel segment for which this form is being from Table 3.1. completed (e.g., Sta. 72+00.00). Date of Inspection: Enter the month, day, Panel Num ber: If present enter the and year the inspection is performed. predetermined panel number for the segment for which this form is being completed (e.g., Inspector(s): Enter the inspector(s) first initial 101). and last name. Year Built: Enter the year during which Sketches: Provide detailed sketches of defects construction of the tunnel was completed. found in areas of the tunnel or auxiliary spaces that is not covered by the standard forms that Liner Type: Enter the appropriate acronym are provided in Chapter 5, Section A. from Table 3.1. (3) Tunnel Segment Photo Log Sheet Date of Inspection: Enter the month, day, and year the inspection is performed. Line: Enter the given name of the system line that is being inspected (e.g., A, Blue, Market Inspector(s): Enter the inspector(s) first initial Street, etc.). and last name. T rack: Enter directional description of track Photos: Provide relevant information for being inspected (e.g., inbound, outbound, any photos that are taken within that tunnel north, east, south, west, etc.). segment. Include as much detail as possible within the description section. It would be Nam e of Station Ahead: Enter name of helpful to take photographs of the same station (subway or ground) that is next along conditions or defects as previous inspections, direction of train traffic. so that the rate of deterioration can be Nam e of Station Behind: Enter name of ascertained. station (subway or ground) that is next in

FEDER A L HIGHW AY ADMINISTRATION Tunnel Inspectio n Manual | 25 TUNNEL AGENCY NAME HIGHWAY TUNNEL FIELD INSPECTION FORM TUNNEL SEGMENT CONDITION CODES

GENERAL INFORMATION

Tunnel Name

Begin Station End Station

Panel Number

Year Built Liner Type

Date of Inspection / / Inspector(s)

Condition Codes (0 = Worst ➡ 9 = Best; See Chapter 4 for Ratings Schedules)

Upper Plenum (if present) Rating Roadway Rating Underside of Roof Underside of Ceiling/Roof Slab Top of Ceiling Slab Top of Invert Right Wall (if applicable) Right Wall Left Wall (if applicable) Left Wall

Lower Plenum (if present) Miscellaneous Appurtenances Underside of Invert Safety Walks Bottom of Plenum Railings Right Wall (if applicable) Utility/CCTV Supports Left Wall (if applicable) Finishes (Check one) ❑ Excellent ❑ Good ❑ Fair ❑ Poor

Comments:

26 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION TUNNEL AGENCY NAME HIGHWAY TUNNEL FIELD INSPECTION FORM SUPPLEMENTAL TUNNEL SEGMENT SKETCHES

GENERAL INFORMATION

Tunnel Name

Begin Station End Station

Panel Number

Year Built Liner Type

Date of Inspection / / Inspector(s)

THIS SPACE TO BE USED FOR SUPPLEMENTAL SKETCHES, AND/OR COMMENTS

FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 27 TUNNEL AGENCY NAME HIGHWAY TUNNEL FIELD INSPECTION FORM TUNNEL SEGMENT PHOTO LOG SHEET

GENERAL INFORMATION

Tunnel Name

Begin Station End Station

Panel Number

Year Built Liner Type

Date of Inspection / / Inspector(s)

Roll Counter No. No. Description

28 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION TUNNEL AGENCY NAME RAIL TRANSIT TUNNEL FIELD INSPECTION FORM TUNNEL SEGMENT CONDITION CODES

GENERAL INFORMATION

Line Track

Name of Station Ahead

Name of Station Behind

Begin Station End Station

Panel Number

Year Built Liner Type

Date of Inspection / / Inspector(s)

Condition Codes (0 = Worst ➡ 9 = Best; See Chapter 4 for Ratings Schedules)

Track Area Rating Miscellaneous Appurtenances Rating

Underside of Roof Safety Walks Concrete Track Supports Railings Right Wall Utility Supports Left Wall

Comments:

FEDER A L HIGHW AY ADMINISTRATION Tunnel Inspectio n Manual | 29 TUNNEL AGENCY NAME RAIL TRANSIT TUNNEL FIELD INSPECTION FORM SUPPLEMENTAL TUNNEL SEGMENT SKETCHES

GENERAL INFORMATION

Line Track

Name of Station Ahead

Name of Station Behind

Begin Station End Station

Panel Number

Year Built Liner Type

Date of Inspection / / Inspector(s)

THIS SPACE TO BE USED FOR SUPPLEMENTAL SKETCHES, AND/OR COMMENTS

30 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION TUNNEL AGENCY NAME RAIL TRANSIT TUNNEL FIELD INSPECTION FORM TUNNEL SEGMENT PHOTO LOG SHEET

GENERAL INFORMATION

Line Track

Name of Station Ahead

Name of Station Behind

Begin Station End Station

Panel Number

Year Built Liner Type

Date of Inspection / / Inspector(s)

Roll Counter No. No. Description

FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 31 E. METHODS OF ACCESS positioned as directed by the Manual on Uniform Traffic Control Devices (MUTCD). This document is To access the various structural elements for up-close endorsed by the Federal Highway Administration visual inspection requires that additional equipment be (FHWA) and is published by the American Traffic used. A man-lift truck, a rail-mounted vehicle, ladders, Safety Services Association (ATSSA), the Institute of and/or removable scaffolding is required. Transportation Engineers (ITE), and the American These types of equipment will permit the inspectors Association of State Highway and Transportation to gain an up-close, hands-on view of most of the Officials (AASHTO). Also, the Manual for Work Zone structural elements. Binoculars can also be used to Traffic Control Devices should be reviewed. It should locate surface defects from nearby manlifts or ladders, be noted that some local jurisdictions might require where up-close access is difficult to achieve. It is the presence of the local or state police in the event preferred, however, that up-close, non-destructive of a tunnel closure or partial closure. This would testing be used on all tunnel surfaces. be to help ensure the safety of the inspection team and the motorist that typically would be using the

tunnel. F. SAFETY PRACTICES Another significant duty of the inspection team is to 2. Rail Transit ensure that safety practices are followed at all times. For rail transit tunnels, inspectors should take Along with the safety of inspection personnel, the extra precaution to avoid contact with the third inspection teams should use caution when inspecting rail or catenary system. If possible, the third rail or to prevent danger to the public, to tunnel personnel, catenary system should be deenergized in the area and to members of the inspection team. If possible, where the inspection is taking place. This can be it is best to have the owner close the tunnel when accomplished during pre-planning coordination inspections are being conducted. Also, all inspectors should wear reflective vests. Other safety practices that with the tunnel owner. Lock-outs and tags must are more specific to highway and transit tunnels are be used to engage the switch to ensure that the discussed below. power does not inadvertently re-energize while the inspection is occurring. If the power cannot be 1. Highway de-energized, it is suggested that the tunnel owner For highway tunnels, appropriate protective devices provide appropriate personnel to remain with the and vehicles should be properly positioned when inspection team during the inspection period. In using lifts and ladders, and where deemed necessary addition, most rail transit agencies will require that to warn that equipment is in the roadway. All a flagman be present when conducting inspections traffic control devices should conform to and be in the track area.

CHAPTER 4: INSPECTION PROCEDURES – GENERAL DISCUSSION A. INSPECTION OF CIVIL/ The visual inspection must be made on all exposed STRUCTURAL ELEMENTS surfaces of the structural elements. All noted defects should be measured and documented for 1. Frequency location. Severe spalls in the concrete surface should be measured in length, width, and depth. The tunnel owner should establish the frequency Severe cracks should be measured in length and for up-close inspections of the tunnel structure width. Corrosion on steel members should be based on the age and condition of the tunnel. For measured for the length, width, and depth of the new tunnels, this time period could be as great as corrosion. The inspectors should clear away debris, five years. For older tunnels, a much more frequent efflorescence, corrosion, or other foreign substances inspection time period may be required, possibly from the surfaces of the structural element prior to every two years. This up-close inspection is in performing the inspection. Once the defect is noted, addition to daily, weekly, or monthly walk-through it should be classified as minor, moderate, or severe general inspections. as explained in the following sections. 2. What to Look For Particular attention should be paid to determining if differential settlement has occurred in transition This section provides the procedures for inspections areas of the tunnel. Transition areas are those in as well as the definitions of defects common to which the tunnel support conditions change, such concrete, steel, masonry, and timber structures. as between sections of rock and soil tunneling The identification of structural defects will be or between the tunnel and ventilation or station accomplished via both visual inspection and non- buildings. The location of these areas should destructive techniques. be evident from any existing as-built drawings.

32 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION Differential settlement is often the cause of other (1) Scaling defects, which is why extra time should be spent The gradual and continuing loss of surface investigation these transition areas. mortar and aggregate over an area classified as In addition to visual inspection, structural elements follows: should be periodically sounded with hammers • Minor Scale – Loss of surface mortar up to to identify defects hidden from the naked eye. 6 mm (¼ in) deep, with surface exposure of As a result of a hammer strike on the surface, the coarse aggregates. structural element will produce a sound that indicates if a hidden defect exists. A high-pitched • Moderate Scale – Loss of surface mortar sound or a ringing sound from the blow indicates from 6 mm (¼ in) to 25 mm (1 in) deep, good material below the surface. Conversely, a dull with some added mortar loss between the thud or hollow sound indicates a defect exists below coarse aggregates. the surface. Such a defect in concrete may signify a • Severe Scale – Loss of coarse aggregate delamination is present or that the concrete is loose particles as well as surface mortar and the and could spall off. A hollow sound in timber may mortar surrounding the aggregates. Depth indicate advanced decay. Once the defect is found, of loss exceeds 25 mm (1 in). the surface in the vicinity of the defect should be tapped until the extent of the affected area is (2) Cracking determined. This procedure is to be applied to A crack is a linear fracture in the concrete concrete and timber surfaces but should also be used caused by tensile forces exceeding the tensile on steel especially where corrosion is evident. strength of the concrete. Cracks can occur For concrete or masonry surfaces that are accessible, during curing (non-structural shrinkage a non-destructive, ultrasonic test method such as cracks) or thereafter from external load “Impact-Echo” may be utilized. Impact-Echo is an (structural cracks). They may extend partially acoustic method that can determine locations and or completely through the concrete member. extent of flaws/deteriorations, voids, debonding Cracks are categorized as follows: of re-bars, thickness of concrete. The use of this • T ransverse Cracks – These are fairly straight method helps to mitigate the need for major retrofit since the deterioration can be detected at an early cracks that are roughly perpendicular to stage and repairs performed. the span direction of the concrete member. They vary in width, length, and spacing. It should be noted that in the 1960s some tunnel These cracks may extend completely owners began to develop maximum allowable through the slab or beam as well as through rates of water infiltration to be used as a guide to curbs and walls supporting the safety walk. determine original design and subsequent repairs if the amount of infiltration increases. One such • Longitudinal Cracks – These are fairly owner was the Bay Area Rapid Transit (BART) straight cracks that run parallel to the span system in California; they set a limit of 0.8 liters/ of the concrete slab or beam. They vary in minute per 75 linear meters (0.2 gpm per 250 width, length, and spacing. The cracks may linear feet) of tunnel. This translates to 3 liters/ extend partially or completely through the minute per 300 linear meters (0.8 gpm per 1000 slab or beam. linear feet) of tunnel. Some tunnel owners have • Horizontal Cracks – These cracks generally adopted this criteria while still others may use a occur in walls but may exist on the sides limit of 3.8 liters/ minute per 300 linear meters (1 of beams where either encased flanges or gpm per 1000 linear feet) of tunnel. These limits reinforcement steel have corroded. They are are for reference purposes only, with the main similar in nature to transverse cracks. emphasis for determining repair needs placed on the location of the leak and the condition of the tunnel • Vertical Cracks – Vertical cracks occur in components that are affected. For this reason, walls and are similar to longitudinal cracks minor, moderate, and severe leakage rates are given in slabs and beams. in the following sections for use in classifying • Diagonal Cracks – These cracks are roughly individual leaks. Also, it is important for the tunnel parallel to each other in slabs and are inspector to be aware of any tunnel waterproofing skewed relative to the centerline of the system that was installed during the construction structure. They are usually shallow and of the tunnel. Many of the common civil/structural are of varying length, width, and spacing. defects are listed below: When found in the vertical faces of beams, a) Concrete Structures (Refer to ACI 201.1R-92 for they signify that a potentially serious representative pictures of these defects) problem exists.

FEDER A L HIGHW AY ADMINISTRATION Tunnel Inspectio n Manual | 33 • Pattern or Map Cracks – These of the surface of the concrete leaving small interconnected cracks vary in size and form holes. Generally, a shattered aggregate particle networks similar to that of sun cracking will be found at the bottom of the hole, with observed in dry areas. They vary in width a part of the fragment still adhering to the from barely visible, fine cracks to well- small end of the pop-out cone. defined openings. They are found in both • Minor – Leaving holes up to 10 mm (0.40 slabs and walls. in) in diameter, or equivalent. • D-Cracks – These cracks are a series of fine • Moderate – Leaving holes between 10 mm cracks at rather close intervals with random (0.40 in) and 50 mm (2 in) in diameter, or patterns. equivalent. • Random Cracks – These are meandering • Severe – Leaving holes 50 mm to 75 mm irregular cracks on the surface of concrete. (2.0 in to 3.0 in) in diameter, or equivalent. They have no particular form and do not Pop-outs larger than 75 mm (3 in) in logically fall into any of the classifications diameter are spalls. described above. (6) Mudballs All cracks in non-prestressed members may be classified as follows: These are small holes that are left in the surface by the dissolution of clay balls or soft • Minor - Up to 0.80 mm (0.03 in). shale particles. Mudballs should be classified • Moderate - Between 0.80 mm (0.03 in) and in the same way as pop-outs. 3.20 mm (0.125 in). (7) Efflorescence • Severe - Over 3.20 mm (0.125 in). This is a combination of calcium carbonate leached out of the cement paste and Any crack over 0.10 mm (0.003 in) in a other recrystalized carbonate and chloride prestressed member should be classified as compounds, which form on the concrete severe. Any crack ≤ 0.10 mm (0.003 in) should surface. be classified as moderate. (8) Staining (3) Spalling Staining is a discoloration of the concrete Spalling is a roughly circular or oval surface caused by the passing of dissolved depression in the concrete. It is caused by materials through cracks and deposited on the separation and removal of a portion the surface when the water emerges and of the surface concrete revealing a fracture evaporates. Staining can be of any color roughly parallel, or slightly inclined, to the although brown staining may signify the surface. Usually, a portion of the depression corrosion of underlying reinforcement steel. rim is perpendicular to the surface. Often (9) Hollow Area reinforcement steel is exposed. Spalling may be classified as follows: This is an area of a concrete surface that produces a hollow sound when struck by a Minor • – Less than 12 mm (½ in) deep or 75 hammer. It is often referred to as delaminated mm (3 in) to 150 mm (6 in) in diameter. concrete. • Moderate – 12 mm (½ in) to 25 mm (1 in) (10) Honeycomb deep or approximately 150 mm (6 in) in diameter. This is an area of a concrete surface that was not completely filled with concrete • Severe – More than 25 mm (1 in) deep and during the initial construction. The shape greater than 150 mm (6 in) in diameter of the aggregate is visible giving the defect a and any spall in which reinforcing steel is honeycomb appearance. exposed. (11) Leakage (4) Joint Spall This occurs on a region on the concrete This is an elongated depression along an surface where water is penetrating through expansion, contraction, or construction joint. the concrete. This defect should be classified as described • Minor – The concrete surface is wet above. although there are no drips. (5) Pop-Outs • Moderate – Active flows at a volume less These are conical fragments that break out than 30 drips/minute.

34 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION • Severe – Active flows at a volume greater (5) Protection System than 30 drips/minute. Steel is generally protected by a paint system, b) Steel Structures by galvanizing, or by the use of weathering steel. Most existing structures use either paint (1) Corrosion or galvanized steel. Paint systems fail through Corroded steel varies in color from dark red peeling, cracking, corrosion pimples, and to dark brown. Initially, corrosion is fine excessive chalking. The classification of the grained, but as it progresses, it becomes flaky degree of paint system deterioration is tied to or scaly in character. Eventually, corrosion both the physical condition of the paint and causes pitting in the member. All locations, the amount of corrosion of the member as characteristics, and extent of the corroded follows: areas should be noted. The depth of severe • Minor – General signs of deterioration pitting should be measured and the size of of the paint system but no corrosion yet any perforation caused by corrosion should present. be recorded. Corrosion may be classified as follows: • Moderate – Paint generally in poor condition and corrosion is present but not • Minor – A light, loose corrosion formation serious. (No section loss.) pitting the paint surface. • Severe – Paint system has failed and there is • Moderate – A looser corrosion formation extensive corrosion and/or section loss. with scales or flakes forming. Definite areas

of corrosion are discernible. c) Masonry Structures • Severe – A heavy, stratified corrosion or (1) Masonry Units corrosion scale with pitting of the metal The individual stones, bricks, or blocks should surface. This corrosion condition eventually be checked for displaced, cracked, broken culminates in loss of steel section and crushed, or missing units. For some types of generally occurs where there is water masonry, surface deterioration or weathering infiltration. can also be a problem. (2) Cracks • Minor – Surface deterioration at isolated Cracks in the steel may vary from hairline locations. Minor cracking. thickness to sufficient width to transmit light • Moderate – Slight dislocation of masonry through the member. Any type of crack is units; large areas of surface scaling. serious and should be reported at once. Look for cracks radiating from cuts, notches, and • Severe – Individual masonry units welds. All cracks in the steel will be classified significantly displaced or missing. as severe. (2) Mortar (3) Buckles and Kinks The condition of the mortar should be Buckles and kinks develop mostly because of checked to insure that it is still holding damage arising from thermal strain, overload, strongly. It is particularly important to note or added load conditions. The latter condition cracked, deteriorated, or missing mortar if is caused by the failure or the yielding of other deterioration is present such as missing adjacent members or components. Erection or displaced masonry units. or collision damage may also cause buckles, • Minor – Shallow mortar deterioration at kinks, and cuts. isolated locations. (4) Leakage • Moderate – Mortar generally deteriorated, This occurs on a region of the steel surface loose, or missing mortar at isolated where water is penetrating through a joint or locations, infiltration staining apparent. crack. • Severe – Extensive areas of missing mortar; • Minor – The steel surface is wet although infiltration causing misalignment of tunnel. there are no drips. (3) Shape • Moderate – Active flows at a volume less Masonry arches act primarily in compression. than 30 drips/minute Flattened curvature, bulges in walls, or other shape deformations may indicate unstable • Severe – Active flows at a volume greater soil conditions. than 30 drips/ minute.

FEDER A L HIGHW AY ADMINISTRATION Tunnel Inspectio n Manual | 35 (4) Alignment • Moderate – Checks with less than 15 percent penetration into the timber The vertical and horizontal alignment of the perpendicular to the plane of stress or tunnel should be checked visually. isolated checks with less than 40 percent (5) Leakage penetration parallel to the plane of stress. A region on the masonry surface where water • Severe – Checks greater than 15 percent is penetrating through a joint or crack. penetration into the timber perpendicular to the plane of stress or numerous checks Minor • – The masonry surface is wet greater than 40 percent penetration parallel although there are no drips. to the plane of stress. Moderate • – Active flows at a volume less (4) Fire Damage than 30 drips/minute. Classification is based on the amount of fire • Severe – Active flows at a volume greater damage. than 30 drips/minute. • Minor – Black or charred surface. No d) Timber Structures appreciable section loss. (1) Decay • Moderate – Less than 15 percent section Decay is the primary cause of timber loss. deterioration and is caused by living fungi, • Severe – Greater than 15 percent section which feed on the cell walls of timber. Molds, stains, soft rot (least severe), and brown or loss. white rot (most severe) are common types of (5) Hollow Area fungi that cause decay. Timber may become discolored and soft and section loss may A hollow area indicates advanced decay in the occur. Any decay should be noted and the interior of a timber member or the presence amount of section loss should be recorded. of insects. All hollow areas should be noted as Decay may be classified as follows: to size and location. • Minor – Discoloration of timber, molds, or (6) Leakage stains present A region on the timber surface where water • Moderate – Timber surface soft with section is penetrating through a joint, check/split, or loss less than 15 percent. the timber itself. • Severe – Brown or white rot present with • Minor – The timber surface is wet although section loss greater than 15 percent. there are no drips. (2) Insects • Moderate – Active flows at a volume less than 30 drips/minute. Any presence of insect infestation should be noted and type of insect recorded, if • Severe – Active flows at a volume greater known. Saw dust or powdered dust on than 30 drips/minute. or around the timber member may also e) Connection Materials indicate the presence of insects and should be noted. Termites and carpenter ants are (1) Bolts common types of insects that cause timber deterioration. The connection bolts on fabricated concrete, steel, and cast iron liners may be discolored (3) Checks/Splits due to moisture and humidity conditions Checks are cracks in timber, which extend in the tunnel. This condition does not partially through the timber member and downgrade the structural capacity of the are caused by shrinkage due to drying or bolt. Particular attention should be given to seasoning of the timber. Cracks that extend bolts in regions of leakage to ensure that completely through the member are called no detrimental loss of section has occurred. splits. All checks should be noted along with If losses in section are observed, such bolts the percentage of penetration through the should be noted for replacement. Also, the member. Checks may be classified as follows: location of all missing or loose bolts should be noted. • Minor – Surface checks perpendicular to the plane of stress or isolated checks parallel to • Minor – Bolts are discolored, but have no the plane of stress. section loss.

36 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION • Moderate – Bolts are deteriorated with up to with the tunnel owner in advance and be prepared 15 percent section loss. to take the “critical action.” Oftentimes, this type of action is required for delaminated concrete that • Severe – Bolts are deteriorated with greater is on the verge of falling. The inspection team, than 15 percent section loss. However, bolts tunnel personnel, or a specialty contractor could with deterioration approaching 50 percent possibly perform the removal. This activity can be or more should be replaced. very dangerous and all safety precautions should (2) Gaskets be taken to prevent injury to inspectors and repair personnel. Gaskets between segmental tunnel liners can be lead, mastic, or rubber. These gaskets 4. Condition Codes can become dislodged from the joint due to Elements will be rated using the guidelines infiltrating water or loosening of the joint explained below. A numerical rating of 0 to 9 will bolts. They also can fail due to chemical or be assigned to each structural element, 0 being the biological deterioration of the material caused worst condition and 9 being the best condition. by the infiltrated water. Structural movements This rating system is a modified form of the one of the liner can also tear or otherwise distort described in the Bridge Inspector’s Training Manual the gasket and cause it to leak. All gasket published by the FHWA. A general description of deficiencies should be noted as to extent and the rating system is shown below in Table 4.1 and location. in Table 4.2 this system is specifically related to 3. Safety – Critical Repairs different liner types. The inspection may reveal severe defects that If a tunnel owner desires to use this system for could pose danger to the traveling public, tunnel mechanical or electrical systems or other tunnel personnel, or inspection team members. When appurtenances, then the codes can be adapted to this occurs, this particular severe defect should be represent a smaller set of conditions. An example categorized for a “critical repair.” This categorization would be to give numbers to the following would deem that one of the following critical conditions: excellent, good, fair, poor, and serious. actions be taken: This may be done in order to track conditions through the use of a tunnel management software • Close the tunnel until the severe defect is removed program. or repaired if such a defect is accessible by vehicles or trains The rating is dependent upon the amount, type, • Cordon off the area from public access until the size, and location of defects found on the structural defect can be removed or repaired element as well as the extent to which the element retains its original structural capacity. To judge • Shore up the structural member if this is the extent to which the structural element retains appropriate. its original structural capacity, the inspector must It is imperative that the inspection team coordinates understand how the element is designed and how

Rating Description 9 Newly completed construction. 8 Excellent condition - No defects found. 7 Good condition - No repairs necessary. Isolated defects found. 6 Shading between “5” and “7.” 5 Fair condition - Minor repairs required but element is functioning as originally designed. Minor, moderate, and isolated severe defects are present but with no significant section loss. 4 Shading between “3” and “5.” 3 Poor condition - Major repairs are required and element is not functioning as originally designed. Severe defects are present. 2 Serious condition - Major repairs required immediately to keep structure open to highway or rail transit traffic. 1 Critical condition - Immediate closure required. Study should be performed to determine the feasibility of repairing the structure. 0 Critical condition - Structure is closed and beyond repair. Table 4.1 – General Condition Codes

FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 37 the defect affects this design. To aid the inspectors the tunnel. This condition does not downgrade in evaluating specific conditions for the various the structural capacity of the bolt. Particular kinds of tunnel elements, more specific guidelines attention should be given to bolts in regions are presented hereafter to ensure consistency in of leakage to ensure that no detrimental loss assigning condition codes. of section has occurred. If losses in section are observed, such bolts should be noted for 5. Tunnel Segments replacement. a) Cut-and-Cover Concrete Box Tunnels and • The tunnels should be generally observed for Concrete/Shotcrete Inner Liners uniform cross-sectional shape from radial soil For several highway tunnels and for station areas pressures. As a means of monitoring possible in rail transit tunnels, the concrete/ shotcrete changes in cross section, measurements surfaces may be covered with another finish should be taken at approximately 60 m (200 material as described under Tunnel Finishes in ft) intervals on the inside face of the liners Chapter 2, Section A, Part 5. For ceramic tile between spring lines and from the underside and epoxy finishes, the general condition of the of the ceiling/roof at 12:00 to the top of rail underlying concrete surfaces is to be evaluated for rail transit tunnels or to top of walkway for and assessed a condition rating based upon the highway tunnels. Yellow paint should be used cracks and leakage through the finish material. to identify the measurement locations. The ratings for the elements of the tunnel liners are In addition to the descriptions of potential based on the general condition codes in Table defects presented in Chapter 4, Section A, Part 2, 4.1 and for degree of deterioration as shown in the concrete/shotcrete elements should be rated Table 4.2. according to the Condition Code Summary in Table 4.2. c) Rock Tunnel Liners The inspector needs to use good engineering These include cast-in-place concrete and shotcrete judgment when assessing the overall condition liners. rating of the segment being inspected. Although The entire exposed portion of the tunnel liner the specific guidelines presented in Table 4.2 above the roadway slab or rail transit invert are an excellent tool to ensure consistency of slab should be inspected for typical concrete evaluations among different inspectors, the deficiencies described in Chapter 4, Section A, defects presented will not always fall into the Part 2. In addition, the lining should be generally categories. For example, if a segment of the cut- observed for uniform cross-sectional shape. As and-cover concrete tunnel shows no defects (i.e., a means of monitoring possible changes in the no delaminations, no spalls, and no exposed cross section, measurements should be taken at reinforcement steel) other than one severe crack approximately 60 m (200 ft) intervals between with severe active leakage, the inspector may still the spring line or vertical sidewalls and from the want to rate this segment in “poor condition” underside of the ceiling/roof at tunnel centerline because a major repair is required to restore the to the top of the walkway for highway tunnels element to good condition. or the top of rail for rail transit tunnels. Yellow b) Soft-Ground Tunnel Liners paint should be used to mark the measurement locations. These liners include fabricated steel, precast concrete, cast iron or masonry liners, as well as The ratings for the rock tunnel, concrete/ connection bolts and gaskets on the fabricated shotcrete linings are based on the rating scale and liners. In addition to the descriptions of potential descriptions given at the beginning of this section defects presented in Chapter 4, Section A, Part 2, in Table 4.1 for degree of deterioration and as the inspector should be aware of the following supplemented in Table 4.2. requirements for these liners: d) Timber Liners • The ends of precast concrete liners may have The exposed portion of the timber liner shall be an embedded steel plate across the full width of inspected for typical timber deficiencies described the liner plus steel plate inserts for bolting two in Chapter 4, Section A, Part 2. The ratings for end-to-end liners together. The condition of the the timber liners are based on the rating scale and embedded steel plate is synonymous with the descriptions given at the beginning of this section precast liner and therefore should be inspected in Table 4.1 for degree of deterioration and as for degree of corrosion. supplemented in Table 4.2. • The connection bolts on fabricated concrete, e) Track Supports steel, and cast iron liners may be discolored due to moisture and humidity conditions in The track supports in this section are for direct

38 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION

repair repair decay

– and

minor liner

No exhibits

exhibits of minor defects splits.

originally –

timber

but –

Liners as decay,

leakage.

moderate found. moderate

tween minor Timber condi ti o n Timber contain

between be

Isolated locations “7.” “5.” completed minor and required

Timber water

condi ti on en t

condi ti on

defects isolated and and

functioning cessary.

Newly No Shading Shading “5” Fair repairs is designed. numerous and checks, leakage. members Shading “3” construction. Excell Good ne isolated checks, minor

of of one

ft) ft)

repair repair

spalls, cracks

– or

but than lining lining (10 (10 No leakage.

minor staining

Min Liners –

exposed.

m presence – minor

cracks no 3m

contains

3 is a and and

moderate

active

to but

found. efflorescence.

required designed. condi ti o n Concrete/ than not

liner Tunnel with of between moderate ft) between cumferential

. “7.” “5.”

are completed

delaminations, cir (5 moderate cement condi ti on

condi ti on cracking

and and

Rock defects m present

cumferential moderate greater

florescence,

Shading Shading “5” Fair repairs element is functioning originally Concrete/shotcrete contains cir 1.5 intervals, longitudinal crack, ef to Minor map are reinfor Shading “3” Newly construction. Excell en t No Good necessary shotcrete minor at intervals presence

ft)

(10 for

than

leakage at minor of 3 one liners locations defects. Precast at

throughout

presence

retightening.

is more

concrete,

ss. y

than

or not minor cracks lo te

precast

minor

and isolated liner isolated

presence concrete leakage

and

liners. corroded more precast

but Steel,

greater modera have section contain . have spalls

Liners

liners. minor active moderate

(not

Summar no

Precast

Steel, a

numerous found. with replacement

surface

liners

liners between required panels

bolts with discolored, cracks loss. Tunnel

are

necessary

have

moderate Code and between contains are defects

but exhibits moderate

require walk “5.” “7.”

designed.

intervals

repairs gaskets to liners minor

No masonry liners section have

repairs

– bolts ft) and and

Ground the -

shapes, present and

safety No and Connection only

Masonry (10 is Minor construction. – minor “3” “5”

Masonry

corrosion Soft

–

panels

m segments)

and

originally 3 iron, masonry Condition with and plates,

through as shapes, significant -

cracks. condi ti on crack. walk liner

leakage Connection cast and

surface liners no between between locations. ft)

Steel

completed

4.2 condition two (5

condition plates,

minor iron, safety minor with m

minor

occurring

s isolated every Moderate Shading Excell en t Good concrete, defects. of concrete one efflorescence intervals. i Shading Fair functioning cast Steel but and two 1.5 efflorescence Newly

Table

ft)

exist

map (10 –

spalls unls Tunnel

no element element

elements is

cracks Minor – elements originally 3

minor minor minor

but but – Box

spalls,

Minor

as to steel Liners moderate

staining moderate found.

ons

and

ft) efflorescence efflorescence. to necessary

condi ti o n

Concrete

and certain with of of

between between (5 ning “5.” “7.” Inner

isolated C over moderate

required completed

concrete

- Concrete/ Shotcrete

leakage. cement

defects conditi on m

condi ti on

minor and and he

and repairs delaminati present. t -

1.5 No functio and

– Shading Shading “3” is designed. contain at intervals presence and active delaminations, cracking, on reinfor exposed. No although contain deficiencies presence No are Shading “5” Fair repairs Cut Newly construction. Excell en t Good

Isolated – no element

loss.

defects Minor

– originally moderate,

but

–

with

sever

but

found. necessary. section condi ti o n Minor,

between between

“5.” “7.” found. required completed

conditi on

condi ti on

and isolated and

defects repairs present General General pti Descri on

functioning

Shading Shading “3” significant Fair repairs is designed. and are Shading Shading “5” No Good No defects Newly construction. Excell en t

4 5 6 7 9 8 Rating

FEDERA LHIGHWAY ADMI N I STRTION A Tunnel Inspection Manual | 39

liner and

The

Lining and . the Timber

Liner and decay – –

– severe

and as Major

leakage of

capacity highway of

– are

liner area. keep Numerous cracked

to Liners all numerous splits, loads.

required and traffic.

to 50%

deteriorated. closed

required lost designed. defects of of the open significantly is

have extensive

condi ti o n

condition condi ti on

over repair.

splits, design are surface. members Timber checks, repairs transit has

functioning

conditi on

extensively

rail not

ructure

Serious Major immediately st or contains decay leakage timber timber completely Critica l has deflected lining sustain Critica l Structure beyond Poor repairs is originally elements moderate checks, over 50%

to to

are

and up up

The

and

Lining

the cracks,

and – cracks lining has – lining lining has

spalls – and

Major

exposed

of capacity l highway Liners –

o functioning keep cracked spalls, loss. and t Exposed

efflorescence, all steel loads. stee

required longitudinal and severe

traffic. to 50% designed.

staining. loss.

closed

not not

required

lost

open significantly is Tunnel

condi ti o n is condition condi ti on and

repair.

section design are

cumferential repairs transit leakage. has cement surface cement

conditi on

extensive section cir

extensive extensively Rock extensive

originally rail 40%

Serious Major immediately structure or Concrete/shotcrete has delaminations, active reinfor to Critica l has deflected lining sustain Critica l Structure beyond Poor repairs element as Concrete/shotcrete has and with leakage, Delaminations present over lining reinfor 15%

the

liner are or no

is layers, The

or repair. some capacity ection

repairs.

severe between segment.

section section Severe The

and can missing is precas

all

achieve loose contains

Conn deterioration loose

are traffic.

Connection

The loss age lost

beyond immediately tunnel

(continued)

masonry masonry

and

are to to 50%

retaining efflorescence, delaminations,

extensive leak

longer

the required. and elements immediate the locations. up have The masonry

transit locations. and

Liners loading. still Masonry material no section sections of units,

the . he

required. t required locations. and rail cracks, active

50% exhibit can closed

within

15% closure

extensive or are

that without isolated of is

major several

design e Tunnel

to serious

loadings. at Summary capacity at

although

repairs severe masonry Severe

locations. liners with the up through that , isolated such

loads

repairs

excess elements at

the locations nsive, highway

design Delaminations in with Major Structure units. Immediat such deterioration deteriorated deteriorated with Ground

Code cracks missing -

certain to – – –

exte capacity carrying prevalent

liner that isolated design Major support -

locations. extensive or of are –

Soft

at deflected occurring

rate are

the open major load is have iron segments original

such

staining.

numerous masonry design loose bolts

longer

mode several

at the cast

ondi ti on their have contains

deteriorated deteriorated condi ti on condition deteriorated c and are no at mortar missing

severely

of support leakage dislocation Condition

condition and or are are structure

elements

can

are missing and original -

sustain

elements to severely and bolts missing Critica l steel, deterioration full degree numerous leakage, slight missing active adjacent liner bolts loose Seriou s keep liner and longer Masonry and occurring Connection loss Critical Poor

4.2

are

up up

Table s Tunnel the exposed

Concrete Concrete

and – staining. staining. has has

spalls contain – –

and

Major

numerous highway

repairing –

with and cracks,

should Box spalls, keep and loss. and loss.

functioning

steel steel Liners of

required

traffic. 50% to Exposed

closed

closure

not

required efflorescence,

designed. cracks is Study open elements severe contain

surface is condi ti on condition

odt onconditi

Inner repair.

C over

section section are

Concrete/ Shotcrete

te leakage,

repairs transit cement cement

conditi on

sive leakage. structure.

feasibility and

- 40% 15% rail and

Critica l Structure beyond delaminations, delaminations, and reinfor to Critical Immediate required. determine to performed the the Delaminations present over concrete reinfor to Serious Major immediately structure or Concrete exten Cut Poor repairs element originally elements modera extensive severe

and – –

– and

Major present.

highway

–

repairing should

functioning keep

are

of required determine traffic. to

designed.

closed

closure not not

to required

is Study open is condi ti on condi ti on condition

repair.

are

defects

transit repairs

conditi on

ired. structure. feasibility General General pti Descri on originally

rail

the Critica l Structure beyond Critica l Immediate requ performed the structure or Seriou Major immediately Severe Poor repairs element as

0 1 2 3 Rating

40 | Tunnel Inspecti on Manual FEDERA LHIGHWAY ADMI N I STRTION A fixation fasteners to concrete plinth pads, flooding of the tunnel space, thus posing a continuous concrete pedestals, and the invert safety hazard to the tunnel occupants. Transit slab. tunnels are particularly sensitive to this due to the amount of equipment that can reside These concrete elements should be inspected for on the tunnel invert such as the signals and the deficiencies described in Chapter 3, Section A, communications equipment, and the third Part 2 and rated according to the general criteria rail power systems. Excessive ponding of water listed at the beginning of this section. around such equipment can lead to equipment f) Finishes malfunctioning and potential shut down of the system. As described previously, the primary tunnel Similarly to the tunnel finishes above, it is finishes include ceramic tiles, porcelainenameled recommended that the inspector use a rating metal panels, precast concrete panels, and epoxy scale of excellent, good, fair, and poor condition. coatings. Whereas it does not make sense to The rating should be based on the particular use a rating scale of 0 to 9 for such finishes, the system component’s ability to convey or store inspector could use ratings such as excellent, the required amount of water, i.e., whether it is good, fair and poor condition that follow the clogged or leaking. general definitions given at the beginning of this section. h) Miscellaneous Tunnel Appurtenances For ceramic tiles, the inspector should lightly These appurtenances include railings, safety tap a majority of tiles to determine if they are walks, utility supports, CCTV camera supports, loose from the substrate. Such tapping will easily enclosures adjacent to the roadway/track etc. reveal a hollow sound if the tiles have been These miscellaneous elements are to be carefully dislodged. Where hollow areas are noted, the inspected for the degree of deterioration in the inspector should freely define the extent of the elements as well as the extent to which they hollow area by tapping all adjacent tiles. The area retain their original design structural capacity. should be so noted in the inspection findings. In The inspector shall assign a rating for each addition, the inspector should evaluate the tiles element based upon the general ratings listed at for reflectivity and general condition (broken or the beginning of this section and in Table 4.1. missing).

For porcelain-enameled metal panels and precast B. INSPECTION OF MECHANICAL SYSTEMS concrete panels, it is crucial that the attachments

to the substrate be carefully evaluated and 1. Frequency assessed, as a loose panel would pose a dangerous condition. For metal panels, any corrosion of the It should be noted that if a proper preventive panels along the edges or at scrapes/nicks, will maintenance program is strictly adhered to, the indicate a downgrading of the surface condition. main purpose of an in-depth inspection is to verify For precast concrete panels, careful attention that the mechanical systems are performing as should be given to determine if there are any expected. For this reason, recommended preventive cracks or delaminated areas in the panels. maintenance procedures and frequencies for specific mechanical systems and equipment are listed in Epoxy coatings are not structural in nature, but the accompanying Maintenance and Rehabilitation do offer a protective covering to the concrete Manual. Table 4.3 lists the inspection frequencies for for changing environmental conditions or for highway and rail transit agencies throughout the additional reflectivity to improve visibility in country for their mechanical systems, which include the tunnel. Note the condition of the coating pumps, fans, motors, etc. Also, a percentage of all primarily due to peeling or debonding from the the tunnel owners that inspect their mechanical substrate. systems are given for each specific frequency. g) Drainage Systems The inspection frequencies shown should only be It is crucial that the tunnel drainage system be used as a guide to what is currently done, not as inspected to ensure that it is capable of handling a suggestion of what should be done. It is up to the water flow for which it was designed. the tunnel owner to determine the frequency of This water flow could be ground water from these in-depth inspections. They can be performed the exterior of the tunnel lining, rain water concurrently with the civil/ structural inspections that enters the portals or vent structures, and or as deemed necessary by the owner because of the drainage from emergency fire protection systems age of the mechanical equipment and the amount of equipment needed for proper tunnel operation. during their use. Failure of this system could It is difficult to determine from the data provided result in ponding of the water and subsequent

FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 41 Table 4.3 – Mechanical Inspection Frequency

Type of

Months

Months Months

Daily

Months

Months Months

Agency

Weekly

Monthly

3 6

12 24 36 84

120

Twice/Month

X X X X X X X X X X Highway 4.0% 4.0% 28.0% 4.0% 4.0% 20.0% 24.0% 4.0% 4.0% 4.0% X X X X X X Rail Transit 8.3% 8.3% 50.0% 8.3% 16.7% 8.3%

in Table 4.3 the actual scope of the inspection • Note the physical condition of each fan, airway, being conducted. It can be assumed that a frequent louver, motor-operated dampers, and drive inspection (generally less than semi-annually, but trains. dependent on the equipment being inspected) is • Verify that each fan and the associated typically a walk-through visual inspection in which motor-operated dampers and components are the inspector is only looking at critical mechanical operational. equipment to verify that it is functioning properly. On the other hand, a less frequent inspection • Engage a special testing firm to perform (generally semi-annually or greater) should be an vibration analysis on the fans, motors, and indicator of a full, in-depth inspection in which bearings during typical fan operations and every piece of mechanical equipment is inspected inspect the fan drive system and bearings. and its condition assessed to ensure proper • Ensure that the airways, where accessible, are operation. free of obstruction and debris. 2. What to Look For • Test the operation of the CO monitoring The mechanical inspection will consist of verifying equipment (if such a system exists in highway the condition and operation of tunnel equipment tunnels). and systems. The inspection will include a review of b) Air Conditioning the physical condition of each piece of equipment for damage due to environmental and operational The inspection of the air conditioning systems in conditions. Any procedures involving the operation control rooms, etc., should include the following of system components must be coordinated with items: the tunnel owner prior to performing any testing. • Review the maintenance records for each piece Each system or piece of equipment should be of equipment and note any special or frequent checked for operation, unless operation of the previous maintenance problems. equipment would cause damage to equipment and/ or inspection personnel, or significant disruption • Note the physical condition of air handling to the operation of the tunnel. Any equipment units, condensing units, packaged units, that cannot be operated should be identified, its chillers, pumps, cooling towers, exposed air physical condition noted, and such information distribution systems, cooling piping, and immediately reported to the tunnel owner. The terminal units. inspection should encompass the following systems: • Verify that the system is operational. The tunnel ventilation, air conditioning, heating, temperatures at the time of the inspection may controls, plumbing, tunnel drainage, fire protection, dictate if the system is able to be in operation. and wells / septic systems. Each system should be inspected as follows: • Engage a special testing firm to perform vibration analysis and inspections on chillers, a) Tunnel Ventilation cooling towers, and pumps. The inspection of the tunnel ventilation system • Engage a special testing firm to perform lube oil should include, as a minimum, the following analysis on all bearing lubricants. items: c) Heating • Review the maintenance records for each piece of equipment and note any special or frequent The inspection of the support area heating system previous maintenance problems. should include the following items:

42 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION • Review the maintenance records for each piece include the following items: of equipment and note any special or frequent • Review the maintenance/inspection records for previous maintenance problems. the system and note any unusual maintenance • Note the physical condition of air handling issues. units, pumps, steam and water distribution • Note the physical condition of the fire systems, terminal units, boilers, exposed air protection system in the tunnel and tunnel distribution systems, heating piping, and steam support areas. This will include the fire converters. extinguishers, hose connections, pumping • Engage a special testing firm, preferably one systems, piping, circulating pumps, and hose that is commissioned by the National Board reels. of Boiler and Pressure Vessel Inspectors, to • Note the physical condition of the fire analyze the boilers to determine their operating protection storage tanks, alarms, and level efficiency and to inspect the boiler breeching switches. for corrosion and holes. • Check fire control panel for faulty detectors, • Verify that the system is operational. The signals, and wiring. temperatures at the time of the inspection may dictate if the system is able to be in operation. C. INSPECTION OF ELECTRICAL SYSTEMS d) Controls 1. Frequency The inspection of the tunnel controls should include a visual observation that the control As with the mechanical systems, it should be noted panel indicators represent the operating that if a proper preventive maintenance program condition(s) of the equipment each control is strictly adhered to, the main purpose of an serves. in-depth inspection is to verify that the electrical systems are performing as expected. For this reason, The use of a SCADA (Supervisory Control and recommended preventive maintenance procedures Data Acquisition) System often controls the and frequencies for specific electrical systems entire facility. These systems operate with a and equipment are listed in the accompanying minimal amount of hardware maintenance, with Maintenance and Rehabilitation Manual. Table 4.4 the exception of the component level sensors. lists the inspection frequencies for highway and Software changes for additional programming rail transit agencies throughout the country for and periodic upgrades are required to maintain inspecting electrical systems. Also, the percentage of flexibility and reliability of system operation. tunnel owners that inspect their electrical systems is e) Plumbing given for each specific frequency. The inspection of the support area plumbing These frequencies should only be used as a guide to system should be conducted according to any what is currently done, not what should be done. It applicable plumbing code requirements and is up to the tunnel owner to determine the frequency should also include the following: of and which items should be checked during these in-depth inspections. They can be performed • Review the maintenance records for the concurrently with the civil/ structural inspections plumbing system and note any special or or as deemed necessary by the owner because of frequent maintenance problems. the age of the electrical equipment and the amount • Note the physical condition of the bathroom of equipment needed for proper tunnel operation. fixtures, water heaters, and drainage system. It is difficult to determine from the data provided in Table 4.4 the actual scope of the inspection

• Verify that the plumbing fixtures are being conducted. It can be assumed that a frequent operational and the piping is free of leakage. inspection (generally less than semi-annually, but • Look for watermarks on tunnel surfaces to dependent on the equipment being inspected) is identify locations of leaks in plumbing system. typically a walk-through visual inspection in which the inspector is only looking at critical electrical

f) Tunnel Drainage equipment to verify that they are functioning The tunnel drainage system including sump properly. On the other hand, a less frequent pumps should be inspected to determine if the inspection (generally semi-annually or greater) tunnel drains are clear of debris to permit water should be an indicator of a full, in-depth inspection runoff to flow freely through the drains. in which every piece of electrical equipment is inspected and its condition assessed to ensure proper g) Fire protection operation. Further recommendations on inspections The inspection of the fire protection system should are given in NETA MTS 1 and NFPA 70B.

FEDER A L HIGHW AY ADMINISTRATION Tunnel Inspectio n Manual | 43 Table 4.4 – Electrical Inspection Frequency

Type of

Months

Months Months

Daily

Months

Months Months

Agency

Weekly

Monthly

3 6

12 24 36 84

120

X X X X X X X X X X Highway 3.1% 3.1% 15.6% 3.1% 3.1% 28.1% 34.4% 3.1% 3.1% 3.1% X X X X X Rail Transit 15.4% 61.5% 7.7% 7.7% 7.7%

2. What to Look For • Check that adequate working space is provided in accordance with NFPA 70, Article 110 and The electrical system inspection will consist of is clear in front of equipment with no material verifying the condition and operation of all of the stored in the working space. following systems: power distribution, emergency power, lighting, fire detection, and communication. • Evaluate the condition of enclosures and Each of these systems are described herein and are to conduit and ensure that all enclosures and box be inspected for the specific requirements listed below covers are in place, conduits are not broken, etc. and the following general items: • Visibly inspect wiring systems for damage and • Visibly inspect wiring systems for damage and corrosion. corrosion. • Check power distribution system for conformity • Ensure that all enclosures and box covers are in to NFPA 70 and NFPA 130. place and secure. • Check that all disconnects are properly • Check for conformity to NFPA 70, 70B, 70E, 72, identified as to what items they disconnect. 130, and NETA MTS 1. • Check that all loads are properly identified as to the source or means of disconnects. • Check that all disconnects are properly identified as to the items they disconnect. • Check all motor controllers for proper operation. • Check that all loads are properly identified as to the source or means of disconnect. • Have a NETA testing agency perform a thermographic (infrared) inspection for hot

• For all large power systems, Electrical Safety spots and an internal inspection, and note any Operating Diagrams should be posted to comply deficiencies. Have this same agency review the with OSHA and NFPA 70E. previous maintenance records to see if prior a) Power Distribution System discrepancies were corrected. Verify that all tests meet industry standards, including NETA MTS1. This system consists of the electrical equipment, wiring, conduit, and cable used for distributing b) Emergency Power System electrical energy from the utility supply (service This system consists of the electrical equipment, entrance) to the line terminals of utilization wiring, conduit, and cable used for providing equipment. The system would include equipment electrical power in case of utility service failure. such as transformers, switchgear, switchboards, Equipment included in this system consists of unit substations, panelboards, motor control emergency generators or uninterruptible power centers, starters, switches, and receptacles. supply (UPS) systems, transfer switches, and other Specific inspection includes: equipment supplying emergency power. • Take voltage and load readings on the electrical • Ascertain the ability of the emergency power system using any of the installed meters. system to operate when the normal power fails, by disabling the normal power supply (i.e., the • Check that all indicator gages on the supply that supplies any transfer switch or other transformers show that fluid levels, means of transferring loads) and operating the temperatures, and pressures are within range. emergency system with selected emergency • Check for signs of damage and overheating of loads for a sufficient period to evaluate its all equipment. condition.

44 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION • Have a NETA testing agency perform an internal e) Communication System inspection and an inspection for hot spots, and This system consists of the communication note any deficiencies. Have this same agency equipment (SCADA, CCTV cameras, telephones, review the previous maintenance records to see radios, etc.) used to provide communication if prior discrepancies were corrected. Verify that within and from the tunnel. all tests meet industry standards, to include NETA MTS1 and NFPA110. • Verify the operation of the SCADA system by ensuring a positive indication is received for c) Lighting System each required operation. This system consists of the electrical equipment, • Verify that the CCTV cameras, telephones, wiring, conduit, cable, luminaries, sensors, radios, or other communication devices are and controllers used to provide lighting for the operational. tunnel. • Inspect traffic signals for proper operation • Measure the light levels within highway tunnels during all phases. using an Illuminating Engineering Society (IES) • Verify that any over-height detectors are not LM-50 device and compare the results against triggering at any heights just below the desired the requirements of IES RP-22. setting and also verify that they are triggering at • Measure the light levels at intervals suggested or just above the desired setting. by IES LM-50. D. INSPECTION OF OTHER SYSTEMS/ • Measure the light levels at emergency egress APPURTENANCES exits and compare with the IES Handbook recommendations. 1. Inspection of Track Elements • Inspect all lighting that is above the roadway It is recommended that rail transit owners require surfaces for visible damage, to include corroded their internal inspectors, outside consultants, or or damaged housings, loose attachments, specialized testing agencies be familiar with and broken lenses, and burnt out bulbs. Also, note if follow the recommended procedures established by lenses should be cleaned. their own internal guidelines or the current revision of the US DOT’s Federal Railroad Administration – • Verify the operation of the lighting controls for Office of Safety’s, Code of Federal Regulations for the different ranges of nighttime and daylight Title 49, Track Safety Standards Part 213 Subpart A illumination. to F, Class of Track 1-5 (TSS Part 213). The current • For transit tunnels, verify that all emergency revision of this document is dated June 9th, 2001. In and continual-use lighting is operational and fact, it is recommended that each inspection team provides the required amount of illumination. be required to have a copy of this “pocket-size” book and any owner’s specific requirements available • For transit tunnels, test operation of Emergency when conducting track inspections. Trip Switch (ETS) lighting, which is linked to the third rail power system to indicate when TSS Part 213 provides the following guidelines for third rail power is properly shut off. These lights class of track and maximum operating speeds for are typically spaced every 240 m (800 ft). passenger trains shown in Table 4.5. d) Fire Detection System It is not the intent of this manual to duplicate the material in TSS Part 213. Rather, key elements of This system consists of control panels, initiating track will be described and the general deficiencies devices (heat and smoke detectors, pull-stations, that an inspector must look for and evaluate when etc.), notification appliances (strobes, horns, etc.), conducting track inspections will be listed. wiring, conduit, and cable used to detect a fire in Table 4.5 – Passenger Train Operating Speeds the tunnel. Maximum Allowable Operating • Inspect the fire detection system by operating Class Speed for Passenger Trains, the drill switch and assuring that all of the of Track km/h (mph) annunciators and notification appliances operate. Class 1 25 (15) • Check existing records to determine if the Class 2 50 (30) system has been tested at regular intervals in accordance with NFPA 72. NFPA 72 requires that Class 3 100 (60) a copy of the records for the last seven years be Class 4 130 (80) available. Class 5 140 (90)

FEDER A L HIGHW AY ADMINISTRATION Tunnel Inspectio n Manual | 45 a) Frequency vertical cracks in the steel, horizontal and vertical split heads, transverse and compound TSS Part 213 Subpart F describes the frequencies fissures, fractures, split web, piped rail, bolt- for inspecting various classifications of track. hole crack, head web separation, broken base, It also explains how such inspections can be detail fracture, engine burn fracture, broken performed by vehicle or on foot. Inspection or defective weld, and surface defects. See TSS frequencies vary from twice weekly for typical Part 213 and the Rail Defect Manual compiled rail transit Class 4 and 5 track to weekly for lower by Sperry Rail Service for explanation of these speed track (Classes 1 through 3). TSS Part 213 defects. The severity of these defects range Subpart F also provides inspection frequency from minor to major. guidelines for switches, track crossings and lift rail assemblies or other transition devices on (2) Gage moveable bridges. These requirements include The gage of the track is the distance from monthly visual inspections on foot and the the center to center of rail heads measured at physical operation of mechanized switches every right angles to the rails in a plane five-eighths three months. In addition, TSS Part 213 requires of an inch below the top of the rail head. that the rail on all Class 3 and higher track The gage may deviate from construction be inspected for rail or rail joint defects with over time, thus exceeding tolerances for specialized rail defect detection equipment at tangent and curved tracks. TSS Part 213 gives least once a year. the appropriate gage distance according to The questionnaires sent out revealed that rail classification of track as follows in Table 4.6: transit owners perform track inspections that vary (3) Alignment from daily to yearly based upon their internal procedures. The established frequencies need not Alignment of tracks may not deviate from change unless the requirements of TSS Part 213 uniformity more than the amounts shown in are not being achieved. Table 4.7: b) What to Look For Table 4.6 – Track Gage Distances This section provides general guidance Class of Track Gage must be at least But not more than on defects that occur in track elements as listed in TSS Part 213, Subparts C, D, and Class 1 1400 mm (4’ – 8”) 1450 mm (4’ – 10”) E. Specifically, these Subparts cover the Class 2 and 3 1400 mm (4’ – 8”) 1444 mm (4’ – 9 ¾”) following track elements: Class 4 and 5 1400 mm (4’ – 8”) 1438 mm (4’ – 9 ½”) • Subpart C – Track Geometry (Gage, Alignment, Curves – Elevation and Table 4.7 – Track Alignment Speed Limitations, Elevations of Curved Track – Runoff, and Track Surface). Tangent Track Curved Track The deviation of The deviation of The deviation of • Subpart D – Track Structure (Ballast, the mid-off-set the mid-ordinate the mid-ordinate Crossties, Gage Restraint Measurement Class of from a 18.6 m from a 9.3 m (31 from a 18.6 m Systems, Defective Rails, Rail End Track (62 ft) line1 may ft) chord2 may (62 ft) chord 2 Mismatch, Continuous Welded Rail, not be more than not be more than may not be more Rail Joints, Torch Cut Rail, Tie Plates, Rail Fastening Systems, Turnouts and mm (inches) mm (inches) than mm (inches) Track Crossings, Switches, Frogs, Spring 3 Rail Frogs, Self-Guarded Frogs, and Frog Class 1 125 (5) N/A 125 (5)

Guide Rails and Guard Faces – Gage). 3 Class 2 75 (3) N/A 75 (3) • Subpart E – Track Appliances and Track- Class 3 43 (1¾) 43 (1¾) 43 (1¾) Related Devices (Derails). An inspection program should ensure Class 4 37 (1½) 25 (1) 37 (1½) that each of the track elements in each Class 5 18 (¾) 12 (½) 15 (�/) Subpart are reviewed and evaluated to 1 maintain safe operation of the trains. The ends of the line shall be at points on the gage side of the A brief description of the inspection line rail, 15 mm (� / in) below the top of the railhead. Either required for some of the major track rail may be used as the line rail; however, the same rail shall be elements is as follows: used for the full length of that tangential segment of track. 2 The ends of the chord shall be at points on the gage side of the (1) Rail outer rail, 15 mm (� / in) below the top of the railhead. Inspect the rail for horizontal and 3 N/A – Not Applicable

46 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION (4) Curves (8) Ballast The maximum crosslevel on the outside rail Inspect the ballast for condition. Insufficient of a curve may not be more than 200 mm (8 or fouled ballast is described as any ballast in) on Track Classes 1 and 2 and 175 mm (7 that will not a) transmit and distribute in) on Classes 3 through 5. the load of the track and railroad rolling equipment to the subgrade; b) restrain the (5) Fasteners/Bolts/Spikes track laterally, longitudinally, and vertically Each of these elements is extremely important under dynamic loads imposed by railroad for safe operation of the rail transit system, rolling equipment or thermal conditions; c) especially in securing the gage of the track. provide adequate drainage for the track; and Spikes should be inspected to ensure they d) maintain proper track crosslevel, surface, are tight and snug against the rail if they are and alignment. used for lateral restraint of the rail. Fasteners (9) Rail Joints include special clips or attachments on both regular jointed and continuous welded rail Rail joints occur where the ends of two rails (CWR) and should be inspected for missing, meet and are spliced together with bolts to broken, or loose fasteners. For CWR, fasteners maintain vertical integrity of the rail. These can also serve as longitudinal restraint. joints should be inspected for cracks or loose joint bars; worn joint bars (such that Special testing of the fasteners is required to excessive vertical movement is permitted); ensure the proper clamping force is being broken joint bars; and missing, broken, or applied to restrain the rail. Bolts are used at deteriorated bolts. The proper number of rail joints for splicing the rail or for attaching crossties in the vicinity of the rail joint is also tie plates to the underlying anchorage system, critical and should be reviewed in accordance whether ties or direct fixation. They should be with crossties mentioned before. inspected for condition and missing, loose, or broken fasteners. 2. Inspection of Power Systems (Third Rail/Catenary) (6) Tie Plates a) Third Rail Power System Tie plates are used to distribute the rail uniformly to the supporting tie or concrete (1) Frequency bearing system with grout. These should be It is recommended that visual inspections of inspected for condition and to determine if uniform bearing is being achieved. If point the third rail system be performed for normal loading on the tie plates is prevalent, this tunnel sections or at crossovers in tunnels on a monthly basis. This visual inspection may affect the gage of the rail, alignment, or curvature. should be made on foot and should note any defects that would affect the movements of (7) Crossties the electric rail transit vehicles. In addition, it Crossties support and secure the rail. They is recommended that testing equipment such are typically made of timber or precast as ohmmeters; a direct current power supply, generator, or equivalent alternating current concrete although fiber reinforced plastic ties are currently being manufactured or used to supply; and miscellaneous leads be used to rehabilitate existing timber ties. They should test resistance of rail joints on a yearly basis. be inspected for condition and for effective Any deficiencies should be repaired during support in accordance with TSS Part 213, this testing period. Subpart D, Section 213.109. (2) What to Look For Timber crossties should be inspected to insure The third rail system provides power to that they are not: broken through, split or electric rail transit vehicles via direct contact otherwise impaired such that ballast can work with the third rail from current collectors through or spikes and rail fasteners cannot (shoes) attached to the transit vehicles. The be held, so deteriorated that the tie plate or third rail system is comprised of the steel base of rail can move laterally 12 mm (½ in) contact rail, protection boards, protection relative to the crosstie, or cut by the tie plate board brackets, insulators, insulator caps, through more than 40 percent of the crosstie’s anchors, and negative running rail bonded thickness. joints as shown in Figure 2.19. A brief For concrete crossties, they should be description of the inspection required for inspected for cracks, deteriorated concrete, some of the major third rail system elements spalls, etc. is as follows:

FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 47 (a) Steel Contact Rail Use the following testing equipment to perform the test: The contact rail should be inspected to determine if it is resting evenly and • Ductor, low resistance ohmmeter. uniformly on all insulators, for excessive • Direct Current (D.C.) power supply. wear and damage on the contact surface, • Miscellaneous leads. to determine if its alignment follows the • Generator or equal for Alternating same radius as any curve in the tunnel, Current (A.C.) supply. and to ensure that all ends are terminated (f) Negative Running Rail Bonded Joints with end approach castings. Inspect all negative running rail bonds, (b) Contact Rail Insulators impedance bond locations, turnout and The contact rail should be inspected to crossover bonds to complete a continuous verify that insulators are present, that they negative circuit. Ensure that no defective rest directly on each bracket, and that joints exist. Perform a resistance test on a they are held in place by a centering cup 750 mm (30 in) length of rail across the that forms an integral part of the bracket. joint with a length of solid rail necessary Each insulator shall be covered with an to give an equal resistance. The solid rail insulator cap. This cap is held in place by reading should not be greater than 1200 the lug hole, which is an integral part of mm (4 ft). Use the same equipment as the insulator. Inspect each insulator for described for the contact rail splice test. condition. Those that are dirty should be (g) Third Rail Insulated Anchor Arms thoroughly cleaned; any that are broken or chipped should be replaced. Inspect all bolts, insulators, contact clamps, and anchor plates used at contact (c) Protection Board rail anchor locations. Inspection should Protection boards should be of sufficient note loose or worn bolts, nuts or clamps, length to be supported by not less than broken insulators, or any removal of two brackets. On curves these boards assemblies. should be cut to conform to the radius of b) Catenary Power System the curve. Inspect these boards to ensure they are in good condition, properly (1) Frequency attached, and cover the contact rail. It is recommended that the catenary (d) Protection Board Brackets inspection include two levels – a visual inspection and an in-depth inspection. Two For timber ties, inspect the protection agencies have specific frequency requirements board brackets to determine if the brackets that may be indicative of other rail transit are placed on the long timber ties, that agencies and are discussed herein. These they are horizontally gaged accurately, agencies include Metro-North Commuter that they rest directly on the tie, and that Railroad and AMTRAK. they are fastened by two lag screws. Also, verify that no brackets are installed on ties Metro-North recommends that a visual supporting joints in the running rail. For inspection of the catenary system be made concrete base supports, the brackets are on foot at bi-monthly intervals. They also to be fastened with bolts and a 3 mm (1/8 recommend that an in-depth inspection in) thick polyethylene pad is to be placed be made from a track vehicle with a high- between the steel bracket and the concrete level platform bi-annually. On the other for isolation purposes. hand, AMTRAK recommends that a visual inspection of the catenary system be made (e) Contact Rail Splices from the head end of a train on a weekly All contact rail splice joints, except joints basis. AMTRAK also requires a quarterly at end approaches, should have a bonded geometry car inspection, a yearly catenary joint. Two bonds are required at each car inspection, and a bi-annual up-close bonded joint, one on each side of the inspection and repair be made from the top contact rail. Inspect this bonded joint by of a catenary car, wire train, or highway-rail performing a resistance test on a two- vehicle. foot length across the joint with a length (2) What to Look For of solid rail necessary to give an equal resistance. The solid rail reading should There are at least two documents available not be greater than 800 mm (32 in). that give specific requirements for inspection

48 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION of the catenary system. These include the supporting the catenary system within Catenary System Inspection Procedures the tunnel are in good condition and for the Metro-North Commuter Railroad anchored firmly to the substrate. Note and the Catenary Inspection Manual for any deficiencies. AMTRAK. Since Metro-North was included (b) In-depth Inspection in the inventory for this project, some of their recommended procedures will be briefly The in-depth inspection will be used to defined herein. However, this would not perform the following inspection tasks preclude an owner from using his own or even as well as give inspection personnel the AMTRAK’s recommended procedures. A brief opportunity to complete general repairs description of the inspection required for and preventive maintenance. some of the major catenary system elements • Contact Wire Wear – Check contact is given below. Note that a particular element may have different procedures for wire wear at each registration point with particular attention to phase gaps and a visual inspection than for an in-depth inspection. overlaps. Verify that vertical thickness of contact wire does not measure less than (a) Visual Inspection 11 mm (0.42 in). If this is not the case, In addition to noting general observations then the contact wire should be replaced in that location. for the following elements, a walk- through inspection should record • Clamped Electrical Connectors – excessive arcing in a matrix that Randomly remove and check clamped shows location, train speeds, number connections at “C” jumpers, feeder and type of pantographs, direction of points and full section overlap jumpers travel, climatic conditions, and any for corrosion or burning. If the above unusual circumstances. This will help conditions are found, the clamps should determine if arcing is due to equipment be removed, cleaned, and tightened. mal-adjustment or to a pattern of In addition, high melting point circumstances. grease should be applied to stranded • Support and Registration Insulators conductors. – Check for broken sheds and any • Hangers – Check for evidence of build-ip of deposits that could cause mechanical wear or electrical arcing. tracking. Insulator support steel should Inspect neoprene sleeves between the be checked for missing or loose nuts and messenger and the retainer. any evidence of movement. • Messenger Supports – Check for • Hangers – Check that alignment is electrical tracking across the insulator vertical. Hangers consistently leaning and check stainless steel wire and one direction indicate that stretch or thimbles for signs of mechanical wear; slippage has occurred and this should be replace as necessary. investigated immediately. Make note of detached hangers and determine cause; • Registration Assembly – Check this may be due to loose or damaged registration components at same carbons on pantographs. Check contact location as messenger assembly for wear. wire clip for evidence of impact. Open contact wire clamps, check for wear, and regrease. Inspect hinge pin, • Jumpers – Check “C” jumpers and full clevis pin and all bolted connections. section continuity jumpers at overlaps Tighten or replace as necessary. for loose clamps, movement or evidence of burning and that they do not sag • Support and Registration Insulators below contact wire level. – Check for contamination, signs of electrical tracking, and broken or • Pull-Off Arrangements – Check for chipped sheds. Check tightness of fixing evidence of clamp slippage and ensure bolts into ends of insulators. that heel settings are higher than the contact wire and that the drop bracket • Overlaps – Verify the contact wire is vertical. Verify that the messenger is profiles at overlaps to ensure efficient positioned vertically over the contact transition of the pantographs. Inspect wire at pull-off locations. underside of contact wires for signs of • Anchors – Check to see if the anchors arcing and adjust, if necessary.

FEDER A L HIGHW AY ADMINISTRATION Tunnel Inspectio n Manual | 49 • Section Insulators – Check for evidence Interlocking tests - 2 years of burning of the skids and arcing horns. Trip stops Adjust turnbuckles on the support Height and alignment - monthly hangers of each unit to keep units level Operation - 6 months and vertically in line with contact wire. (2) Communication Systems • Disconnect Switches – Open and close to Specific frequencies for inspection of ensure operation of switches. communication systems range from 3. Inspection of Signal/Communication Systems continuously (by use) to monthly. Examples of these frequencies are shown below: Similarly to track inspections, it is recommended for inspection of signal systems that rail transit owners Emergency telephones - monthly require their internal inspectors, outside consultants, Radiating cables - prior to work or specialized testing agencies be familiar with and Backbone cables - continuously(by use) follow the recommended procedures established Communications by their own internal guidelines or the US DOT’s equipment - per manufacturer. Federal Railroad Administration – Office of Safety’s, As another source of frequency recommenda- Code of Federal Regulations for Title 49, Part tion, a survey of current rail transit tunnel 236 – Rules, Standards, and Instructions Governing owners showed actual inspection frequencies the Installation, Inspection, Maintenance, and Repair for both signal and communication systems of Signal and Train Control Systems, Devices, and that range from daily to every six months, 8 Appliances , further referred to as FRA Part 236. with monthly being most common. For communication systems, the same office of the Federal Railroad Administration has produced b) What to Look For 9 Title 49, Part 220 – Railroad Communications , (1) Signal Systems further referred to as FRA Part 220. However, this publication contains little in regard to inspection Comprehensive and timely inspections and testing and more on actual operations of such of signal systems are necessary due to the systems. possible consequences if a component of the system fails. According to FRA Part 236: It should be noted that there is no current “When any component of a signal system, requirement for rail transit tunnel owners to follow the proper functioning of which is essential to the guidelines in FRA Part 236 or Part 220, but in the safety of train operation, fails to perform lieu of developing their own, many transit agencies its intended signaling function or is not in have adopted these as standards. correspondence with known operating Given the complexity of FRA Part 236, it will not be conditions, the cause shall be determined and reproduced in this manual in its entirety, but rather the faulty component adjusted, repaired or key sections have been identified and generalized replaced without undue delay.” In addition to give basic direction for inspection of signal to the visual and operative inspection systems. To establish a comprehensive signal system procedures given in the above frequency inspection program, it is recommended that a copy section, a brief description of the inspection of FRA Part 236 be consulted directly. required for some additional signal system elements is as follows: a) Frequency • Verify that legible and correct plans are kept (1) Signal Systems at all interlockings, automatic signals, and Specific inspection procedures outlined in controlled points. FRA Part 236 for the various components of • Verify that open-wire transmission lines the signal system range in frequency from 1 operating at voltage of 750 volts or more month to 10 years. Some of these frequencies shall be placed not less than 1,200 mm (4 ft) include the following: above the nearest crossarm carrying signal Switch circuit controller - 3 months or communication circuits. Switch obstruction - monthly • Verify that each wire is tagged or marked so Semaphore/searchlight - 6 months that it can be identified at each terminal. Relays (type dependent) - 2 years Also, verify that tags and wires do not Ground tests (power supplies) - 3 months interfere with moving parts of any signal Insulation tests (cables) apparatus. New - 10 years • Test the operating characteristics of all parts Resistance < 500,000 ohms - yearly of semaphores or searchlights. Timing devices - yearly

50 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION • If a block signal system is being used, then its center line to gage side of the nearest verify that each signal governing train running rail are in accordance with the movements into a block will display its specifications of the carrier. most restrictive aspect when any of the • Ensure that results of all tests performed following conditions are met within the are recorded on preprinted or computerized block: forms provided by the rail transit authority • Occupancy by a train, locomotive, or and are retained until the next record is car. filed or for one year, whichever is greater. • When points of a switch are not closed (2) Communication Systems in proper position. As with signal systems, it is critical that • When an independently operated communication systems be kept in good fouling point derail-equipped with working condition; therefore, accurate and switch circuit controller is not in frequent verification of working condition derailing position. is pertinent. In addition to the procedures described in the above frequency section, the • When a track relay is in de-energized following actions are suggested: position or a device which functions as a track relay is in its most restrictive • Verify that all emergency telephones are in state; or when signal control circuit is proper operating condition by placing a call de-energized. from each location. • Verify that insulated rail joints are • Test signal strength of radiating cable. maintained to prevent sufficient track • Visually inspect backbone cables for signs of circuit current from flowing between the degradation. rails separated by the insulation to cause a failure of any track circuit involved. • Follow all manufacturers’ recommendations for inspection and preventive maintenance • Verify that the trip stop arm is maintained of communications equipment. at the height above the plane of the tops of the rails and the horizontal distance from

CHAPTER 5: INSPECTION DOCUMENTATION A. FIELD DATA depth (if applicable).

For consistency in documenting the inspection 1. Tunnel Structure findings, each inspector should use the following The inspection should be thoroughly and system both to describe the defect and to classify accurately documented. For the tunnel structure, them as minor, moderate or severe: the documentation of severe defects should Description of Defect Classification include a sketch showing the location and size of the defect and a verbal description of the Crack - CR 1 - Minor defect. All severe defects should be photographed; Scaling - SC 2 - Moderate however, a representative photo of minor or Spall - SP 3 - Severe moderate defects will be sufficient. All defects Staining - ST should be described but sketches need only to be Exposed Reinforcement - E made for severe defects. Corrosion - C The sketches of the defect can be made on forms Honeycomb - H developed during the mobilization phase or on Patch Failure - PF computer screens, as appropriate. These forms Hollow Area - HA should show the necessary plan and elevation Debris - D views of the structural element to which they Buckle - B pertain. Blank forms should also be provided for Efflorescence - EF additional sketches where deemed necessary by the inspectors. All defects should be located on Leakage - LK sketches or the computer screen by dimensioning Check - CK their location in reference to the beginning Rot - RT or end of the element. Each defect should be Fire Damage - FD dimensioned showing its length, width, and Paint Deterioration – PD

FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 51 For example, a moderate spall should be in an inspection report format and/or entered into a labeled as SP2, a severe crack as CR3, etc. This structural database for scheduling repairs/rehabilitation designation should be placed on the sketch and and for historical purposes. The following repair connected to the defect by means of a leader to classifications are suggested: clearly identify the defect. Samples of completed 1. Critical field sketches for tunnel segments, developed using both a tablet PC data collector and a As discussed in Chapter 4, Section A, Part 3, a pre-printed form, are shown in Figures 5.1 and defect requires this designation if it requires 5.2, respectively. In addition, Figure 5.3 shows “immediate” action including possible closure of an example of a defect location form for an the structure or areas affected for safety reasons auxiliary space that was completed using a pre- or from system operation until interim remedial printed form. Upon completion of each section measures can be implemented. or miscellaneous appurtenance being inspected, 2. Priority a summary rating sheet as shown in Chapter 3, Section D, Part 3, should be completed as a record Refers to conditions for which further investiga- of the inspection. tions, design, and implementation of interim or long-term repairs should be undertaken on Before placing any other information on a a priority basis, i.e., taking precedence over all form, always complete the spaces at the top of other scheduled work. These repairs will improve the form identifying the structural element. the durability and aesthetics of the structure or This will eliminate any confusion when element and will reduce future maintenance numerous structural elements are completed. costs. Elements that do not comply with code A 35 mm or digital camera should be used to requirements are also in these classifications. take photographs during the inspection. Each Such repairs should be scheduled for completion inspector will keep a log of all photographs within two years. taken. This log should identify the element being inspected, a description of the photograph, 3. Routine the counter number, and the roll number (if Refers to conditions requiring further investiga- appropriate). Examples of photo log sheets and tion or remedial work that can be undertaken as sketch sheets are shown in Chapter 3, Section D, part of a scheduled maintenance program, other Part 3. scheduled project, or routine facility maintenance 2. Track Structure depending on the action required. All items identified in the preventive maintenance program TSS Part 213, Subpart F, Section 213.241 – should also be incorporated in this category. Such Inspection Records requires that rail transit items should be scheduled for completion after owners are to keep records of each inspection two years. performed. This section identifies when the records are to be completed and the method of C. REPORTS record retention – either paper or electronically. Undoubtedly, rail transit owners already have Upon completion of all elements of the inspection, developed in-house forms for these inspections the tunnel owner should require a formal report be so none will be presented herein. It is suggested developed that summarizes the findings from each that these procedures be followed by all rail element that was inspected. This report will be used transit owners, even if it requires changes to their to educate the tunnel owner of deficiencies within current documentation procedures. the tunnel and enable him/her to schedule repairs and allocate sufficient funding. The report should 3. Specialized Testing Reports be supplemented with a computerized database that To inspect certain mechanical, electrical, and includes the rating information on structural elements. other associated track systems requires the use of This database will permit the tunnel owner to query specialized testing agencies and equipment. All and develop reports as necessary for any inspected such reports derived from these special testings element in the tunnel. Below is a suggested outline for shall become a part of the documentation of the the report along with a description of the contents to particular inspection period. be included in each section. • Letter of Transmittal – Formal identification of

B. REPAIR PRIORITY DEFINITIONS report and introduction to the recipient. • T able of Contents – Self-explanatory. When summarizing inspection data and making recommendations for future repairs it is necessary to • List of T ables – Used to identify the title and define categories that prioritize the repairs that are to location of any tables that were used to summarize be performed. These recommendations can be included the inspection findings.

52 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION

_ TUNNEL INSPECTORS

STRUCTURAL INSPECTION DATE

TUNNEL NO. 2

______

STATION EDGE OF NORTH WALL STATION

Rubber Draina g e

System C C C C C C

EF2 EF2 EF2 EF2

* EF2 EF2 Hole 2" Dia.x7" (24 drops /Min.)

7 sf HA EF2 EF2 (LK-2)

E H

* EF2

CR2 * EF2 WEST Stala c ti t e EAST * EF2

CR2 C C C

EF2 EF2 EF2 EF2 EF2

EDGE OF SOUTH WALL Hole 2"x4"x2"Dp. (LK3 Continuously) LENGTH

TOP OF TUNNEL PANEL NO. XX (REFLECTED)

SHEET

Figure 5.1 – Tunnel Inspection Form (Tablet PC Data Collector)

FEDER A L HIGHW AY ADMINISTRATION Tunnel Inspectio n Manual | 53

Figure 5.2 – Tunnel Inspection Form (Pre-Printed Form)

54 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION

______TUNNEL INSPECTORS STRUCTURAL INSPECTION DATE

SHEET

Figure 5.3 –Portal Inspection Form(Pre-Printed Form)

FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 55 • List of Figures and Drawings – Used to identify • Track, Third Rail, Catenary, Signals, and the title and location of any figures or drawings Communications – For the inspection of track, that were used to describe the inspection. traction power, signals, and communications, the inspectors shall discuss the overall findings • List of Photographs – Used to identify the title and provide copies of specialized testing results. and location of any photographs that were taken to document the inspection findings. • Recommendations – This section will include actual recommendations for repair/ rehabilitation • Executive Summary – Provide a concise summary of the tunnel components that were found to of the inspection, findings, and recommended be deficient or that did not meet current code repairs. requirements. The owner may desire that an • General Description – Provide a general estimate of cost be made by the inspectors to description of the tunnel or tunnels that were correct the defective elements. If substantial inspected. This information could include the rehabilitation is required, the owner may request location of the tunnel(s), age, general geometry, a life-cycle cost comparison be made comparing and any other pertinent descriptive information. repair options in the short-term versus long-term rehabilitation. The repair/rehabilitation should be • Inspection Procedures – The procedures used broken down for each of the main tunnel systems to perform the inspection of the various tunnel into the different categories listed below, which elements below should be explained and were defined in the previous section. illustrated if necessary. Recognition should also be given to any special testing agencies that were • Critical used to complete the inspection. • Priority

• Civil/Structural • Routine. • Mechanical • Appendices – The appendices should be used • Electrical to display detailed and extensive inspection • Track, Third Rail, Catenary, Signals, and summaries that were too lengthy to include in the Communications. body of the report, such as structural panel ratings • Inspection Findings – A detailed description of and lighting illuminance levels. Also, reports the results of the inspection should be included for provided by special testing agencies should be the various tunnel elements below. included in their entirety. Other items that should be included in the appendices are special permits • Civil/Structural – For civil/structural elements, or qualifications that were needed to perform the the report should contain descriptions of the inspections. An example of this would be confined various deficiencies found, their locations space entry permits, qualifications, and procedures and their severity. Any special testing, such needed for entering certain areas of a tunnel, such as concrete strength, freeze-thaw analysis, or as the air plenums above or below the tunnel petrographic analysis should be included with space. the findings.

• Mechanical – For the mechanical inspections, the general condition and operation of all This summary report along with the testing results equipment should be described and deficiencies will provide an historical document recording the noted. Specialized testing required to effectively condition of the tunnel and its inherent systems for determine the operational condition of the the period indicated. This document can be compared equipment, such as vibration testing and to documents from future inspections for tunnel oil analyses, shall be included for historical owners to evaluate the overall long term condition of purposes. various tunnel elements. • Electrical – For the electrical inspections, the general condition and operation of all equipment should be described and deficiencies noted. Specialized testing required to effectively determine the operational condition of the equipment, such as power distribution and emergency power, shall be included for historical purposes. In addition, measurement of light levels versus that recommended should be provided to the owner. Where testing agencies performed remedial work along with the testing, such as tightening loose wires, etc., it should be included.

56 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION GLOSSARY

AASHTO American Association of State Highway and ITE Institute of Transportation Engineers Transportation Officials Km/h Kilometers per hour AC Alternating Current mph Miles per hour ATSSA American Traffic Safety Services Association MTS Maintenance Testing Specifications CCTV Closed Circuit Television MUTCD Manual on Uniform Traffic Control Devices Chord A line segment that joins two points on a curve NATM New Austrian Tunneling Method (synonymous with SEM) CO Carbon Monoxide NBIS National Bridge Inspection Standards CWR Continuous Welded Rail NBS National Bureau of Standards DC Direct Current NEMA National Electric Manufacturers Association ETS Emergency Trip Switch NETA InterNational Electrical Testing Association FHWA Federal Highway Administration NFPA National Fire Protection Association FRA Federal Railroad Administration FTA OSHA Occupational Safety and Health Federal Transit Administration Administration Gunite Term commonly used for fine-aggregate PEI Porcelain Enamel Institute shotcrete SEM Sequential Excavation Method gpm Gallons per minute (synonymous with NATM) IES LM-50 Illuminating Engineering Society, Lighting TBM Tunnel Boring Machine Measurements – 50 TSS Track Safety Standards IES RP-22 Illuminating Engineering Society, Recommended Practices – 22 UPS Uninterruptible Power Supply

REFERENCES

Arnoult, J. D., Culvert Inspection Manual FHWA – IP – 86 SYSTRA Consulting, Electric Traction Catenary Inspection – 2, Federal Highway Administration, 1986. Field Manual, AMTRAK, 1998. Bickel, J.; E. King, and T. Kuesel, Tunnel Engineering U.S. Department of Transportation, Federal Railroad Handbook, Second Edition, Chapman & Hall, New Administration – Office of Safety, Code of Federal York, 1996. Regulations, Title 49, Track Safety Standards Part 213, Subpart A to F, Class of Track 1-5, Simmons- Haack, A.; J. Schreyer, and G. Jackel, State-of-the-art Boardman Books, Inc., Omaha, NE, 2001. of Non-destructive Testing Methods for Determining the State of a Tunnel Lining, Tunnelling and U.S. Department of Transportation, Federal Railroad Underground Space Technology, 10.4 (1995): 413- Administration – Office of Safety, Code of Federal 431. Regulations, Title 49, Part 236, Rules, Standards, and Instructions Governing the Installation, Inspection, anual for Metro-North Commuter Railroad, M Maintenance, and Repair of Signal and Train Control Maintenance and Inspection of Constant Tension Systems, Devices, and Appliances, 2001. Catenary Systems. U.S. Department of Transportation, Federal National Fire Protection Association, NFPA 502: Railroad Administration – Office of Safety, Code Standard for Road Tunnels, Bridges, and Other Limited of Federal Regulations, Title 49, Part 220, Railroad Access Highways, 2001. Communications, 2001. Sperry Rail Service, Rail Defect Manual, Sperry Rail Service, 1968.

FEDERAL HIGHWAY ADMINISTRATION Tunnel Inspection Manual | 57

U.S. Department of Transportation Federal Highway Administration

Office of Asset Management Federal Highway Administration U.S. Department of Transportation 400 7th Street, S.W. HIAM-1 Washington, DC 20590

Telephone: 202-366-0392 Fax: 202-366-9981

FHWA-IF-05-002

58 | Tunnel Inspection Manua l FEDER A L HIGHW AY ADMINISTRATION