County approves $3.05 million augmentation for Foresthill Bridge weld-testing and repairs
Loading...
Summary
Public works briefed the board on ultrasonic testing of T1 steel welds on the Foresthill Bridge and the board approved a $3,054,394 amendment to the consultant agreement to complete testing, drilling and incidental repairs and painting.
Placer County public works told the Board of Supervisors on Feb. 18 that ultrasonic inspection of welds on the Foresthill (Four‑so) Bridge has identified a higher-than-expected percentage of weld indications requiring further engineering analysis and limited drill‑out repairs. The board approved an amendment to the consulting agreement to fund the work.
The bridge, a high‑strength T1 steel truss spanning about 730 feet above the North Fork American River, was selected for special testing after Federal Highway Administration guidance required local agencies to examine welds in some older high‑strength steel bridges. Public works director representatives said about 75% of the planned weld inspections are complete and that roughly 37% of inspected welds showed some form of nonconformance; about 14% of the inspected welds had indications that required a drill‑out and crack‑arrest procedure.
Deputy director Matt Randall and project manager staff explained the process: inspectors must remove coating paint at weld locations, access the inside of boxed members (scaffolding, under‑bridge inspection equipment and personnel baskets were used), perform ultrasonic mapping and where a discontinuity is detected, perform limited drill‑outs and install crack‑arrest details per engineering analysis. The county has engaged Atlas Technical Consultants to do inspection, testing and repair design; Atlas works with subconsultant structural engineers and test crews.
The board adopted a resolution authorizing an amendment to the professional services agreement with Atlas, increasing the agreement by $3,054,394 to a new not‑to‑exceed amount of $8,465,381 and authorizing amendments up to 10% of the total for contract administration. Randall told the board the project is largely federally funded through the Federal Highway Bridge program and that county RMR (Road Maintenance & Rehabilitation) funds provide the local match. He said, to date, no indication required the bridge to be closed and that the work is preventative.
Ending: Public works said staff will continue testing, complete engineering analysis on rejectable indications, and return to the board if construction or large capital repairs beyond the current contract scope are required.
