18/01/2011 CONSTRUCTION TECHNOLOGY & maintenance CEM 417 WEEK 3 Stages for construction 1. Building 2. Retaining walls, Drainage 3. Road, Highway, Bridges 4. Airports, Offshore/Marine structure ROADS, HIGHWAYS & BRIDGES 1 18/01/2011 WEEK 3 At the end of week 3 lectures, student will be able to : - Identify the different types of roads, highways and bridges and their respective functions. (CO1; CO3) flash.lakeheadu.ca/.../Highway%20Design%20- %20Class%20notes%202%20- %20Functional%20classification.ppt HIGHWAY Development Process and Functional Classification OVERVIEW OF THE HIGHWAY DEVELOPMENT PROCESS http://www.fhwa.dot.gov/environment/flex/ch01.htm 2 18/01/2011 HIGHWAY DEVELOPMENT PROCESS Highway design is only one element of the overall development process Five stages of highway development process: planning, project development, final design, right-of-way, and construction Different activities with overlap in terms of coordination Flexibility available for highway design during the detailed design phase is limited by decisions on early stages http://www.fhwa.dot.gov/environment/flex/ch01.htm PLANNING Initial definition of the need for any highway or bridge improvement project takes place in this phase Problems identified fall into these categories: Existing physical structure needs major repair/replacement Existing or projected future travel demands exceed available capacity, and access to transportation and mobility need to be increased (capacity). The route is experiencing an inordinate number of safety and accident problems that can only be resolved through physical, geometric changes (safety). Developmental pressures along the route make a reexamination of the number, location, and physical design of access points necessary (access). 3 18/01/2011 PLANNING (CONTD.) Once problem is identified, it is important that all parties agree that the problem exists and that it should be fixed Consider potential impacts of project: How will the proposed transportation improvement affect the general physical character of the area surrounding the project? Does the area to be affected have unique historic or scenic characteristics? What are the safety, capacity, and cost concerns of the community? Answers on this phase FACTORS IN PLANNING http://www.fhwa.dot.gov/environment/flex/ch01.htm PROJECT DEVELOPMENT Environmental analysis intensifies Includes a description of the location and major design features of the recommended project Try to avoid, minimize and mitigate environmental impacts Basic steps: Refinement of purpose and need Development of a range of alternatives (including the "no-build" and traffic management system) Evaluation of alternatives and their impact on the natural and built environments Development of appropriate mitigation 4 18/01/2011 PROJECT DEVELOPMENT (CONTD.) Assess area Consider context and physical location Data collection effort Identify constraints http://www.fhwa.dot.gov/environment/flex/ch01.htm Consider factors and select preferred alternative FINAL DESIGN After a preferred alternative is selected and the project description agreed on upon as stated in the environmental document, the final design occurs The product of this phase is a complete set of plans, specifications, and estimates (PS&Es) of required quantities of materials ready for the solicitation of construction bids and subsequent construction Depending on the scale and complexity, this phase may take from a few months to several years FINAL DESIGN (CONTD.) Need to employ imagination, ingenuity and flexibility Be aware of commitment of previous phases Ability of making minor changes to original concept Design considerations Developing a concept Considering scale Detailing the design 5 18/01/2011 RIGHT-OF-WAY, CONSTRUCTION AND MAINTENANCE During the right-of-way acquisition and construction phases, minor adjustments in the design may be necessary Construction may be simple or complex and may require a few months to several years Maintenance is very important to keep the character of the road Functional Classification FUNCTIONAL CLASSIFICATION Is the process by which streets and highways are grouped into classes, or systems, according to the character of traffic service that they are intended to provide Streets and highways classification Orderly grouping roads based on service Assist in geometric design features In accordance with operational needs Establishes hierarchy of roads Efficient and safe if road serve their purpose 6 18/01/2011 FUNCTIONAL CLASSIFICATION (CONTD.) Assessment of operating conditions Comparison between actual and intended purpose Chance to sort data based on type of road Collision data not yet available Three functional classifications: arterials Collector local roads ROADWAY FUNCTIONAL CLASSES Determined by characteristics: function access density traffic demands trip length expected speed http://www.fhwa.dot.gov/environment/flex/ch01.htm ROADWAY FUNCTIONAL CLASSES (CONTD.) Arterial: highest level of service, high mobility, low access, long trips, fast speeds Collector: less highly developed level of service, lower speed for shorter trips, collects traffic from local roads and connecting them with arterials Local: all roads not defined as arterials or collectors, provides access to land with littler or not through traffic, low speed 7 18/01/2011 SERVICE FUNCTION SOURCE: TAC GEOMETRIC DESIGN GUIDE FOR CANADIAN ROADS FUNCTIONAL CLASSIFICATION IN THE DESIGN PROCESS The first step in the design process is to define the function that the facility is to serve. The level of service required to fulfill this function provides the basis for design speed and geometric criteria within the range of values available to the designer Functional classification decisions are made before the design phase, but there is flexibility in the major controlling factor of design speed DESIGN CLASSIFICATION SYSTEM Source: TAC Geometric Design Guide for Canadian Roads Classification system (differences in) Traffic and land service Design features Operational needs (adjacent land use) For all areas in Canada Rural (R) Urban (U) Lane Local (L) Local (L) Collector (C) Collector (C) Arterial (A) Arterial (A) Expressway (E) Freeway (F) Freeway (F) 8 18/01/2011 DESIGN CLASSIFICATION (CONTD.) Ten primary divisions Design subdivisions Divided (D) or undivided (U) Design speed (value) Example (See Table 1.3.2.1, next slide) RAD (90) UCU (80) Comments Number of classes: 63 Design speed increases from local to freeways All locals street are undivided All freeways are divided RURAL DESIGN CLASSIFICATION SOURCE: TAC GEOMETRIC DESIGN GUIDE FOR CANADIAN ROADS FACTORS CONSIDERED IN CLASSIFICATION Adjacent Land Use: Urban vs. rural classification Service Function: Access to land. Ex: local Service to traffic. Ex: freeways both Traffic Volume: Freeways: high volume Collectors and locals: low volume Flow Characteristics: Freeways: uninterrupted facility Locals; interrupted facility 9 18/01/2011 FACTORS CONSIDERED IN CLASSIFICATION (CONTD.) Running Speed: Generally increase from locals to collectors to arterials to freeways Vehicle Type: Proportion of passenger cars, buses, large trucks Connections: Normal for roads to connect to the same classification or one higher or one lower See Table 1.3.3.1 For Characteristics of Rural Roads See Table 1.3.4.1 For Characteristics of Urban Roads See Table 1.3.4.2 ROAD CONNECTIONS COMMENTS Comments: Rural and urban roads are the same in terms of service function, and land service Volumes are higher on urban roads than on rural roads Design speeds on urban roads are lower than in rural roads Vehicles types are different, especially for local streets Government agency responsible for each type of road: Municipal government -urban: local, collectors Provincial government –rural - freeways Similar roads have similar designs, construction, maintenance and operation Similar roads: similar costs 10 18/01/2011 BRIDGES Development Process and Functional Classification HTTP://WWW.BUZZLE.COM/ARTICLES/TYPES-OF- BRIDGES.HTML Top 20 Most Popular Bridges in the World Other than the above given names, here are some more names of the most famous bridges of the world. Kintai Bridge, Japan . Chengyang Bridge, China . Chain Bridge, Hungary . Akashi-Kaikyo Bridge, Japan . Ponte Vecchio, Italy . Alcántara Bridge, Spain . Pont des Arts, France . Millau Bridge, France . Bosphorus Bridge, Turkey . Chapel Bridge, Switzerland . Charles Bridge, Czech Republic . Galata Bridge, Turkey . Rialto Bridge, Italy . Tsing Ma Bridge, Hong Kong . Jacques Cartier Bridge, Canada . Banpo Bridge, South Korea . Stari Most, Bosnia and . Magdeburg Water Bridge, Herzegovina Germany . Great Belt Bridge, Denmark . Howrah Bridge, India Bridge is not a construction but it is a concept, the concept of crossing over large spans of land or huge masses of water. The idea behind a bridge is to connect two far-off points eventually reducing the distance between them. Apart from this poetic aspect of ‘bridges’, there is a technical aspect to them that classifies bridges on the basis of the techniques of their construction 11 18/01/2011 Beam Bridge: A beam bridge was derived from the log bridge. It is built from shallow steel beams, box girders and concrete. Highway overpasses, flyovers or walkways are often beam bridges. A horizontal beam supported at its ends comprises the structure of a beam bridge. The construction of a beam bridge is the simplest of all the