Bridge Inspection Report Sheet 1 of 17 Capitola Crossing Deck Truss (MP15.89c) April 24, 2012 CAPITOLA CROSSING DECK TRUSS (MP15.89c) BRIDGE INSPECTION REPORT DRAFT Prepared for J.L. Patterson & Associates, Inc. By Modjeski and Masters, Inc. 4510 Pennsylvania Ave, Suite E Charleston, WV 25302 June, 2012 Bridge Inspection Report Sheet 2 of 17 Capitola Crossing Deck Truss (MP15.89c) April 24, 2012 TABLE OF CONTENTS 1.0 INTRODUCTION ..................................................................................................... 3 2.0 DESCRIPTION ........................................................................................................ 4 3.0 INSPECTION PROCEDURE ................................................................................... 7 4.0 PREVIOUS CONSULTANT WORK ........................................................................ 7 5.0 STRUCTURAL CONDITION ................................................................................... 7 5.1 Stringers ............................................................................................................... 7 5.2 Floorbeams .......................................................................................................... 8 5.3 Stringer Cross Frames & Stringer Bracing........................................................ 8 5.4 Top Chord............................................................................................................. 9 5.5 Bottom Chord ....................................................................................................... 9 5.6 Verticals ................................................................................................................ 9 5.7 Diagonals.............................................................................................................. 9 5.8 Top and Bottom Lateral Bracing ...................................................................... 10 5.9 Bearings ............................................................................................................. 10 5.10 Piers .................................................................................................................. 10 6.0 PIN CONDITION ................................................................................................... 11 7.0 CONDITION PHOTOGRAPHS ............................................................................. 12 Bridge Inspection Report Sheet 3 of 17 Capitola Crossing Deck Truss (MP15.89c) April 24, 2012 1.0 INTRODUCTION The Capitola Crossing Deck Truss carries a single track over Soquel Creek in the town of Capitola, California. The bridge is positioned at milepost 15.89 with the main span (15.89c) as the subject of this report on the 31-mile Santa Cruz Branch Line (Branch Line) located along the Monterey Bay between the town of Davenport and Pajaro Junction, California. This report contains documentation of the Bridge Inspection performed on the Capitola Crossing Deck Truss by J.L. Patterson and Associates, Inc. (JLP) and Modjeski and Masters Inc. (MMI). This task was performed under Contract No. RT14019-01 for the Santa Cruz County Regional Transportation Commission (SCCRTC). The intent of this report is to document factual findings of the bridge inspection and no conclusions or recommendations are included here-in. The degree of corrosion is separated into four categories when listed on the figures detailing where the corrosion exists and are defined as follows: 1. Minor corrosion indicates paint failure with surface corrosion and no section loss of the member or any rivets, nuts and bolts that may be present. 2. Moderate corrosion indicates a slight buildup of corrosion with little to no section loss of the members and up to 25% section loss of any rivets, nuts and bolts present. 3. Significant corrosion indicates a large buildup of corrosion with minor section loss of members and up to 50% section loss and flowering of any rivets, nuts and bolts present. 4. Severe corrosion indicates large buildup of corrosion with moderate section loss of members and more than 50% section loss and flowering of any rivets, nuts and bolts present. Other descriptive terms used throughout the report include the following. Concrete is defined as unsound or delaminated when it is hollow sounding when struck with a hammer, and is generally characterized by cracking or voids in the underlying concrete down to the level of the reinforcing steel. Bridge Inspection Report Sheet 4 of 17 Capitola Crossing Deck Truss (MP15.89c) April 24, 2012 2.0 DESCRIPTION The Capitola Crossing consists of a single span open deck, pin connected deck truss that carries a single track over Soquel Creek in the town of Capitola, California flanked by timber trestles on both sides of the main span acting as the immediate approaches to the structure designated segment numbers 15.89b and 15.89d. Beyond the timber trestles, a pre-stressed concrete box stinger span and pre-stressed concrete trough span with respective segment numbers 15.89a and 15.89e exist before the rail transitions back to ground level. For span 15.89c the rail is supported on stringers with floorbeams as the load transfer mechanism to the upper chord. The stringers, floorbeams, top chord, vertical members, and bracing are all fabricated as various built-up sections and are fastened with rivets. Both the top and bottom chord have pin connections at joint locations with the bottom chord members consisting of eye-bar type members. The superstructure supports additional components, including wooden walkways and wooden railings. Two concrete piers with cut stone pier caps support the structure and have unknown foundation support types. Photograph 1 – General view of north approach looking south. Bridge Inspection Report Sheet 5 of 17 Capitola Crossing Deck Truss (MP15.89c) April 24, 2012 Photograph 2 – General view of south approach looking north. Photograph 3 – General elevation view looking upstream at Span 15.89c. Bridge Inspection Report Sheet 6 of 17 Capitola Crossing Deck Truss (MP15.89c) April 24, 2012 Bridge Inspection Report Sheet 7 of 17 Capitola Crossing Deck Truss (MP15.89c) April 24, 2012 3.0 INSPECTION PROCEDURE The team of JLP and MMI performed an inspection on the Capitola Crossing Deck Truss during the period of April 23 through April 24, 2012. The inspection performed for the Santa Cruz County Regional Transportation Commission (SCCRTC) consisted of a condition inspection to support the previous condition assessment and a load capacity rating of the structure. The dates that each of the team members were in attendance on the bridge are as follows: Dan L. Davis (Team Leader) JLP April 23-24, 2012 R. Shawn Brannon, P.E. (Team Leader) MMI April 23-24, 2012 Bradly C. Croop, P.E. MMI April 23-24, 2012 Joseph B. Neeley, E.I.T. MMI April 23-24, 2012 The concrete substructure and lower portions of the truss were inspected by technical access climbing (rappelling). The upper portions of the truss, truss floor system, and rail ties were inspected using a highrail UBIU inspection vehicle (See Photograph 4) while the walkway and walkway railings were inspected from track level. The truss pins were ultrasonically inspected on April 23 and 24, 2012. The results of the ultrasonic pin testing are contained within a separate report. 4.0 PREVIOUS CONSULTANT WORK HNTB had previously performed an inspection and load rating on the Capitola Crossing Deck Truss in April of 2006. 5.0 STRUCTURAL CONDITION 5.1 Stringers The stringers are built-up members and generally had areas of minor section loss due to pitting of the steel on the flanges and webs (See Photograph 5). At connection points with floorbeams the bottom and top flanges and webs exhibited minor to moderate section loss. The flanges at cross frame connection points typically exhibited minor to moderate section loss. Noted deficiencies other than those discussed above are listed in Table 1. Bridge Inspection Report Sheet 8 of 17 Capitola Crossing Deck Truss (MP15.89c) April 24, 2012 Table 1 – Stringer Deficiencies PANEL STRINGER LOCATION NOTE 2 DS - Top flange has 1/8” SL full length 3 US - Bottom flange has 1/8” SL full length 3 DS MIDSPAN Bottom flange has 25% SL full length 3 DS - Bottom flange has 1/8” SL full length 4 US AT FB3 Top flange has 50% SL full length 4 DS AT FB3 Top flange has 50% SL full length SL – Section Loss US – Upstream DS – Downstream FB – Floorbeam 5.2 Floorbeams The floorbeams are built-up members and generally had areas of minor section loss due to pitting of the steel on the flanges and webs. At connection points between the floorbeam and stringers the bottom and top flanges exhibited minor to significant section loss. The exposed ends of the floorbeams generally had minor to moderate section loss due to pitting (See Photograph 6). Noted deficiencies other than those discussed above are listed in Table 2. Table 2 – Floorbeam Deficiencies FLOORBEAM SIDE NOTE 1 - 25% SL on bottom flange under both stringers 1 - 50% SL to top flange at DS stringer connection 2 - 25% SL to top flange at US stringer connection 2 - 25% SL to bottom flange at DS stringer connection 2 - 75% SL to top flange at DS stringer connection 3 - 75% SL to bottom flange at US stringer connection 3 - 90% SL to bottom flange at DS stringer connection 3 - 1/8” SL to bottom flange in general 3 NORTH Bottom flange has 1/2” recess due to corrosion 4 - 1/4” SL to bottom flange at US stringer connection 4 - 1/8” SL to bottom flange at DS stringer connection 4 - 1/8” SL to US end