San Francisco-Oakland Bay Bridge Self-Anchored Suspension Bridge Project Project Team Response to QA/QC Expert Panel Recommendations November 2011 (updated) March 2011 (original) Orthotropic Box East End Girder (OBG) OBG Lifts 12-14 Lifts 1-11 Crossbeams 17-19 Crossbeams 1-16 UPDATED FINAL Prepared by 11/03/11 The Self-Anchored Suspension Bridge Project Team: NOTE TO READER The following updated Project Team Report (dated November 3, 2011) includes supplemental weld data to the March 31, 2011 Project Team Report (Report) and incorporates comments received from the QA/QC Expert Panel and Seismic Safety Peer Review Panel in March/April 2011. The information provided in the updated November 3rd Report encompasses the complete collection of all data for the “welds of interest”, as previously defined in the Report. The steel orthotropic box girder fabrication welding is complete. San(cid:2)Francisco(cid:3)Oakland(cid:2)Bay(cid:2)Bridge(cid:2)(cid:2) Self(cid:3)Anchored(cid:2)Suspension(cid:2)Bridge(cid:2)Project(cid:2) Project(cid:2)Team(cid:2)Response(cid:2)to(cid:2)QA/QC(cid:2)Expert(cid:2)Panel(cid:2)Recommendations(cid:2) November(cid:2)2011(cid:2)(updated)(cid:2) March(cid:2)2011(cid:2)(original)(cid:2) (cid:2) The(cid:2)Self(cid:3)Anchored(cid:2)Suspension(cid:2)Bridge(cid:2)Project(cid:2)Team:(cid:2) (cid:2) PREPARED(cid:2)BY(cid:2) California(cid:2)Department(cid:2)of(cid:2)Transportation(cid:2) Tony(cid:2)Anziano(cid:2) Brian(cid:2)Maroney(cid:2) Ken(cid:2)Terpstra(cid:2) Peter(cid:2)Siegenthaler(cid:2) Bill(cid:2)Casey(cid:2) Ade(cid:2)Akinsanya(cid:2) (cid:2) Consultants(cid:2) Mazen(cid:2)Wahbeh,(cid:2)Alta(cid:2)Vista(cid:2)Solutions,(cid:2)Inc.(cid:2) Karen(cid:2)Wang,(cid:2)HNTB(cid:2)Corporation(cid:2) (cid:2) American(cid:2)Bridge(cid:2)/(cid:2)Fluor(cid:2)Enterprises,(cid:2)Inc.,(cid:2)A(cid:2)Joint(cid:2)Venture(cid:2) Brian(cid:2)Petersen(cid:2) Peter(cid:2)van(cid:2)der(cid:2)Waart(cid:2)van(cid:2)Gulik(cid:2) Bob(cid:2)Kick(cid:2) Kevin(cid:2)Smith(cid:2) Thomas(cid:2)Nilsson(cid:2) Steve(cid:2)Lawton(cid:2) (cid:2) CONTRIBUTORS(cid:2) California(cid:2)Department(cid:2)of(cid:2)Transportation(cid:2) Keith(cid:2)Hoffman(cid:2) Gary(cid:2)Thomas(cid:2) (cid:2) Consultants(cid:2) Marwan(cid:2)Nader,(cid:2)T.Y.(cid:2)Lin(cid:2)International(cid:2) Ted(cid:2)Hall,(cid:2)Bay(cid:2)Area(cid:2)Management(cid:2)Consultants(cid:2) (cid:2) Bay(cid:2)Area(cid:2)Toll(cid:2)Authority(cid:2) Peter(cid:2)Lee(cid:2) (cid:2) California(cid:2)Transportation(cid:2)Commission(cid:2) Stephen(cid:2)Maller(cid:2) Dina(cid:2)Noel(cid:2)(cid:2) (cid:2) (cid:2) i(cid:2) (cid:2) Table of Contents 1.0 EXECUTIVE SUMMARY .................................................................................................................. 1 2.0 INTRODUTION ............................................................................................................................ 3-5 3.0 PROJECT TEAM RESPONSE TO QA/QC EXPERT PANEL RECOMMENDATIONS .................................. 6 3.1 Previously Presented Recommendation #1 ................................................................................7 3.2 Previously Presented Recommendation #2 ................................................................................8 3.3 Additional Recommendations from the Panel #1 .......................................................................9 3.4 Additional Recommendations from the Panel #2 .................................................................... 10 3.5 Additional Recommendations from the Panel #3 .................................................................... 11 3.6 Additional Recommendations from the Panel #4 .................................................................... 12 3.7 Additional Recommendations from the Panel #5 .................................................................... 13 3.8 Additional Recommendations from the Panel #6 .................................................................... 14 3.9 Additional Recommendations from the Panel #7 ............................................................... 15-16 3.10 Additional Recommendations from the Panel #8 ................................................................... 17 4.0 CONCLUSION ............................................................................................................................... 18 ii Table of Contents (continued) 5.0 APPENDICES Statement by the QA/QC Fabrication Expert Panel Letter, dated March 29, 2011 ........................... A Weekly QA/QC VTC Lists / Weekly VTC Meeting Notes ..................................................................... B SAS Steel Fabrication Expert Monthly Review .................................................................................... C Weld Statistics Using New FCAW Welding Process ............................................................................ D Welding Inspection Mapping (updated as of March 16, 2011) ........................................................... E Simplified Service Load PPT ................................................................................................................. F OBG-Cross Beam Tension Mapping Slide Presentation by TYLin/MN ................................................ G Contract Change Order 22 – Revised NDT Table ................................................................................ H Steel Fabrication Expert Panel – Draft Report (November 2010, Issued January 12, 2011 - Rev 9) .... I Project Team Response to “Welding Procedure Requirements for New Welds,” dated October 2009 ..................................................................................................................................................... J Supplemental Data to New FCAW Welding Process Statistics Since March 31, 2011 Report ........... K Supplemental Data - Crossbeams 17 – 19 Bottom Corner Weld UT Summary ................................... L Supplemental Meeting Notes Since March 31, 2011 Report ............................................................ M a) Joint Meeting with the TBPOC-TBSSPRP-QA/QC Expert Consultants (4/25/11) b) SAS Steel Fabrication Monthly Review Meeting Notes (6/8/11 and 6/9/11) November 3, 2011 Documents ........................................................................................................... N a) Final Statement Letter from QA/QC Expert Panel dated November 3, 2011 b) SAS Steel Fabrication Monthly Review Meeting Notes (11/3/11) iii Self-Anchored Suspension Bridge Project Project Team Response to QA/QC Expert Panel Recommendations, March 2011 (original) November 2011 (updated) 1.0 EXECUTIVE SUMMARY The Self-Anchored Suspension (SAS) segment of the San Francisco-Oakland Bay Bridge East Spans Seismic Safety Project is advancing with the ongoing erection of the SAS Orthotropic Box Girders (OBG) as visual testaments to its progress. The SAS segment is part of the overall Toll Bridge Program under the direction of the Toll Bridge Program Oversight Committee (TBPOC). The construction contract is administered by the California Department of Transportation (CT). The Prime Contractor is American Bridge / Fluor Enterprises, Inc., A Joint Venture (ABFJV). The SAS steel OBGs and East End anchorages are being fabricated at Shanghai Zhenhua Heavy Industry Company, LTD. (ZPMC) in Shanghai, China under a contract with ABFJV. Twenty-two of the twenty-eight OBG lifts have been erected as of early March 2011. The remaining six OBG lifts are expected to ship from ZPMC in May and July of 2011. As is the case in all real-world fabrication-construction projects, fabrication is expected to require inspection and some rework. The rework is required to repair rejectable flaws. This document responds to the QA/QC Expert Panel (Panel) recommendations stated in a November 2010 draft report. A main focus to these recommendations is aimed to reduce and effectively eliminate the number of transverse linear indications (TLIs) related to, in part, an excess hydrogen contaminant problem present in the performance of certain welding processes and their environments. Significant and continued expertise and effort have been dedicated to Quality Control (Contractor) and Quality Assurance (Owner) resources to employ the requirements of the Contract Documents to identify and repair rejectable transverse crack-like indications. In some cases, contract changes have been made (i.e. implementation of the new FCAW welding process), and may be made in the future to continually improve the quality of the work and expedite the schedule. Continual efforts to reduce transverse crack-like indications have been on-going since initial discovery in November 2009. To further expand these efforts to the more challenging fabrication of the East End of the SAS, the Project Team solicited the services of the Panel. At the end of a weeklong QA/QC Steel Fabrication meeting conducted in November 2010 at ZPMC, a draft report by the Panel was generated and distributed. This draft report reemphasized earlier welding procedure recommendations made in November 2009 and provided additional recommendations on weld inspection testing and welding procedures and processes. Recommendations can be organized into two categories: 1) Recommendations for evaluation of welding previously performed (OBG Lifts 1-11); and 2) Recommendations for welding to be performed in future work (East End, OBG Lifts 12-14). A well-qualified and complex problem-focused team (Project Team) was assembled to directly and effectively address all elements of the Panel’s recommendations regarding transverse crack-like indications, while advancing the OBG fabrication work to its completion, and provide status reporting to the Toll Bridge Seismic Safety Peer Review Panel (TBSSPRP) and the TBPOC. Weekly videoconferences were held between the Project Team members in China and Oakland to maximize communications and effectively document progress and consensus. Monthly meetings with the Project Team and Panel have also been established to provide opportunity for interaction and updates on progress focused towards Page 1 Section 1.0 Executive Summary the development of a document formally addressing and responding to the recommendations stated in the November 2010 draft report. Through these efforts, the Project Team, along with the Panel, has clarified the intent of the recommendations from which practical and reasonable consensus has been achieved on both the evaluation and the actions to be taken on the completed welds (Lifts 1 thru 11 and Crossbeams 1 thru 16) and future welds (Lifts 12 thru 14 and Crossbeams 17 thru 19). Tremendous effort has been directed to identify weld types and processes that were thought to potentially contribute to the TLIs caused by excess hydrogen contamination in order to eliminate this problem in future welds. Based upon Non-Destructive Examination (NDE) data provided from welds placed after November 30, 2010, the Project Team and the Panel concluded that TLIs caused by excess hydrogen have been effectively eliminated by implementation of multiple enhancements to the welding procedures. The November 2010 draft report conservatively placed all weld types into a broad set of welds of interest, requiring detailed evaluation for all future (East End, Lifts 12 thru 14) welds. However, after a thorough technical evaluation by the Project Team and subsequent consensus from the Panel, it was determined that only a relatively small and select subset of welds was of further interest. The criteria in defining the welds of interest included type of weld, welding procedure used to perform the weld, welding wire, welds subjected to tensile stresses during the service life of the bridge, and weld inspection criteria. In certain cases, additional inspection has been directed either by the Contractor or the Owner. In all cases, the fabrication of the East End meets or exceeds the requirements of the Contract Documents. The majority of the SAS OBG fabrication (Lifts 1 thru 11) has been completed, and as stated previously, has been erected in the field after undergoing the rigorous inspection as required in the Contract Documents. In the early stages of the efforts to address the Panel’s recommendation regarding OBG Lifts 1 thru 11 (Ref. Additional Recommendation From The Panel #6), many welds were thought to be welds of interest prior to all of the supplemental and detailed inspection and bridge analysis data being fully organized and evaluated together. With such information made available, it was determined that the vast majority of the welds in OBG Lifts 1 thru 11 are not welds of interest. The weld inspection data for the relatively small set of welds identified as welds of interest provided in this response document indicates inspection percentages ranging from 50 to near 100%, exceeding contract NDE requirements. Such high percentages of weld inspection using inspection methods required in the Contract Documents and the American Welding Society D1.5 Bridge Welding Code can confidently detect systemic hydrogen generated TLIs. In all cases, detected rejectable indications, including TLIs, were removed and welds repaired as required by the Contract Documents. After review of all data, it has been demonstrated that the investigated welds have in general been of high quality with very low rejection and repair percentages due in large part to the highly automated welding process at ZPMC. Final evaluation results of the OBG steel fabrication, as summarized within this response, clearly confirms that any necessary follow-up actions taken were well-founded and were based on proper technical information and contract administrative procedures. After extensive investigation, review, and consideration, the steel fabrication of the OBGs is advancing and is being completed in compliance with the Contract Documents, including the American Welding Society D1.5 Bridge Welding Code. Page 2 Self-Anchored Suspension Bridge Project Project Team Response to QA/QC Expert Panel Recommendations, March 2011 November 2011 (updated) 2.0 INTRODUCTION Project Background The Self-Anchored Suspension (SAS) segment of the San Francisco-Oakland Bay Bridge East Spans Seismic Safety Project consists of twenty-eight steel Orthotropic Box Girder (OBG) lifts and nineteen crossbeams spanning 605 meters of total length. Fabrication of these steel pieces commenced in late 2007 at Shanghai Zhenhua Heavy Industry Company, LTD. (ZPMC) in Shanghai, China under a contract with American Bridge / Fluor Enterprises, Inc. (ABFJV). Main Focus on Quality Efforts and Issue Resolution Continual efforts to reduce transverse crack-like indications have been on-going since initial discovery in early 2008 and additional discovery in mid-2009. Through a series of destructive tests and evaluations performed in November 2009, an initial assessment of potential excess hydrogen being a root cause was made. While all rejectable crack-like indications were removed and welds repaired in compliance with the Contract Documents, the following improvements were implemented: (cid:2) Modified Welding Procedures were put into effect in a November 2009 report that was prepared by consultants to Caltrans and ABFJV; (cid:2) Amended UT Procedures were developed to address transverse linear crack-like indications; (cid:2) Over-checks of non-destructive testing were performed by ABFJV QC in addition to non- destructive testing performed ZPMC QC. The QA/QC Expert Panel (Panel) To further expand the ongoing efforts to improve quality and place additional emphasis on the more challenging fabrication of the East End of the SAS, the Project Team solicited the services of subject matter expert consultants that are already associated with the project through either ABFJV or Caltrans or Bay Area Toll Authority. Those third party consultants were Mr. Don Rager (Chair of the American Welding Society Code Committee for Structural Steel Welding), Mr. David McQuaid (Chair of the American Welding Society Code Committee for Bridge Steel Welding), Dr. John Barsom (Fracture Mechanics Specialist and Metallurgist) and Mr. Alan Cavendish-Tribe (Professional Welding Engineer). This group of four formed the QA/QC Expert Panel who was tasked to work collaboratively with the Project Team in the requested assessment of quality within the ongoing OBG steel fabrication in China. The steel fabrication and erection of the OBGs, at the time of the QA/QC Expert Panel Visit and development of their November 2010 Draft Report, was as follows: (Reference Exhibit 2.0 below) OBG Lifts 1 through 11, Crossbeams (CB) 1 through 16 - (cid:2) OBG Lifts 1 through 9 and Crossbeams (CB) 1 through 12 were completed, shipped and erected; (cid:2) OBG Lift 10 and CB 13 and 14 were shipped on November 15, 2010; (cid:2) OBG Lift 11 and CB 15 and 16 were 92% complete in fabrication. East End, OBG Lifts 12 through 14 and CBs 17 through 19 - (cid:2) OBG Lift 12 and CB 17 were 83% complete in fabrication; (cid:2) OBG Lifts 13 and 14 and CBs 18 and 19 were 62% complete in fabrication; (cid:2) OBG Lifts 13 and 14 and CBs 18 and 19 had completed their parts fabrication and had commenced segment and crossbeam assembly in which the major and more complicated welding was to be performed. Page 3 Section 2.0 Introduction Exhibit 2.0: OBG Segment Fabrication Status as of November 19, 2010 (Information obtained from Caltrans’ Weekly China Fabrication Status from 11/19/10) Orthotropic Box Girder (OBG) East End Lifts 1-11 OBG Lifts 12-14 Crossbeams 1-16 Crossbeams 17-19 The initial draft report was issued by the Panel at the conclusion of the meetings conducted during the week of November 15, 2010. The Project Team’s response is based on the November 2010 draft report, Revision 9, issued on January 12, 2011. Project Team Response The Project Team, as a special assignment, formed a task group to address, react and respond to the Panel’s recommendations. Proactive measures such as the following were implemented within two weeks from receipt of the report: 1. Weekly videoconferences were held between the Project Team members in China and Oakland to maximize communications and effectively document progress and consensus. 2. Monthly meetings with the Project Team and Panel have also been established to provide opportunity for interaction and updates on progress focused towards the development of a document formally addressing and responding to the recommendations stated in the November 2010 draft report. 3. Extensive “live” (prepared real-time during the meeting) meeting minutes were concurred by all attendees and provided in organized matrices for all weekly and monthly meetings. (Ref. Appendices B and C) Page 4 Self-Anchored Suspension Bridge Project Project Team Response to QA/QC Expert Panel Recommendations, March 2011 November 2011 (updated) Through the weekly and monthly meetings, the Project Team addressed the following major topics in the process of clarifying and responding to the Panel’s recommendations (Ref. Section 3.0): 1. Clarification of the welds of interest. (Ref. Additional Recommendations From The Panel #1 and #2) 2. Welding Process – Implementation of a new FCAW welding process, includes revisions to gas mixture and delivery system, additional focus on controls of preheat, continual evaluation of the new FCAW welding process results focusing on findings of any apparent hydrogen-related TLIs, verification of fracture critical requirements for certain weld repairs are met. (Ref. Previously Presented Recommendation #1 and #2, Additional Recommendations From the Panel #3) 3. Welder Performance – Engaged the Panel in discussions with ZPMC QC on welder performance incentive and disciplinary programs. (Ref. Additional Recommendations From The Panel #4) 4. Inspection – Collected and organized weld inspection mapping for welds of interest and reviewed and evaluated data (Ref. Additional Recommendations From the Panel #6 and #7); confirmed that the CWI process was meeting or exceeding contract requirements. (Ref. Additional Recommendations From The Panel #5) 5. Tension/Compression Mapping – Presented summary of tension/compression mapping to explain in a more visual and more graphical form stress magnitude and range, stress direction and stress location in the efforts to obtain the welds of interest. (Ref. Additional Recommendations From The Panel #6) Page 5