Del Norte Addresses Roadway Safety
Built in 1948, the Big Flat Road at Hurdygurdy Creek Bridge, is a critical route providing access to local residences and to Big Flat campground and off-road hiking trails. Additionally, the bridge is a critical route for forest fire suppression efforts in the event of a wildfire. The existing bridge was a single-lane, two-span steel truss with a concrete deck with concrete seat abutments, and a single concrete column. After nearly 70 years of use, the bridge was rated by Caltrans under the Federal Highway Administration (FHWA) as “structurally deficient.”
Bridge Replacement at Hurdygurdy Creek
The project replaced the existing two-span bridge over Hurdygurdy Creek on the existing alignment. The new bridge is a single-span, pre-stressed, cast-in-place box girder structure. A key challenge for the project involved construction over an active creek, requiring extensive permitting, monitoring, and strict timeframes in which to complete construction.
Ghirardelli’s Dynamic Services
Ghirardelli provided Construction Management and Inspection services for the project. This included diligent contract administration and coordination. Because of the limited work window, our team first reviewed the Baseline schedule, provided monthly schedule updates, and regularly communicated with the design team to make sure construction was completed during the narrow work window. Because our team understood the Environmental Commitment Record, had experience in active stream channels and effectively coordinated with permitting agencies, the project complied with all permits.
Our team also provided public outreach support and developed effective relationships with locals who relied on the road to access their homes and community. We informed neighboring communities of the schedule and potential impact associated with this project, such as traffic on South Fork Road during concrete pours and active construction. Our personnel also ensured that South Fork Road was not adversely impacted during the construction period.
Our field inspectors monitored the contractor’s compliance with project plans, details, and all applicable specifications required to properly construct the project. Our inspectors prepared electronic daily reports, mitigated issues and provided resolutions, conducted safety meetings, and reviewed traffic control plans prior to construction. Our assigned Structures Representative reviewed, approved, and inspected falsework, shoring systems, formwork systems, concrete mix designs, post-tensioning operations, and joint seal calculations. Their efforts helped ensure that the bridge was constructed safely and was structurally sound.
Post Construction Support
After construction finished, our team provided claims management support, project closeout, new as-built plans, completion reports, and cataloged contract records per Caltrans’ file management system.
Delivering the Project on Time Despite Unforeseen Changes
During excavation, it was determined that the bedrock was five feet below the water table, requiring a substantial contract change order the deepen the footing and maintain traffic with the necessary embankment slope to accommodate the deeper excavation. This was a very big concern as the budget and timeline for construction were very limited. If not redesigned and constructed in time, the contractor could have missed the construction window for work over the streambed, resulting in a full-year delay. To keep the project on track, Ghirardelli staff coordinated with the project team to successfully comply with environmental requirements and succeeded in constructing a fully functional bridge before the end of the construction season.