SCH Number 2023100206

Project Info

Title

GPC 22-11 Wolf Creek Road over Wolf Creek Bridge Replacement Project

Description

The bridge has a sufficiency rating of 60.1 and has been designated as functionally obsolete per the Caltrans Structure Maintenance & Investigations, Local Agency Bridge List (July 2015). The functionally obsolete designation is a result of the insufficient deck width. Wolf Creek Road is a two lane road and the clear width of the existing bridge is too narrow to support standard lane and shoulder widths for a two lane facility. Additionally, the existing bridge fails to meet the current Caltrans design standard for freeboard requirements. Hydraulic studies indicate that the existing bridge may be overtopped during a 100-year storm event. Caltrans has reviewed the preliminary details of the project and supports a full replacement scope. The purpose of the proposed project is to provide a replacement structure that is consistent with appropriate Caltrans structural design standards, is placed on a road alignment that meets the appropriate American Association of State Highway and Transportation Officials (AASHTO) roadway geometry standards, and is hydraulically capable of passing and clearing the design storm events (50-year storm plus 2 feet of freeboard and 100-year storm). The replacement bridge will be wider to comply with current AASHTO standards for local rural roads, including 9-foot travel lanes and 2-foot shoulders, plus crash-tested vehicular barriers. A 5-foot sidewalk (Lake County standard) will also be proposed on the north side of the replacement structure to accommodate school children accessing a nearby bus stop. The replacement bridge will be approximately 84 feet long. This length is appropriate for a single span bridge, which would reduce the construction duration and increase the hydraulic capacity of the channel. It is anticipated that deep foundations will be needed to support the replacement bridge. The underlying formation of the soil is rock overlaid by alluvial and fan deposits which have washed down from the mountains. The upper material is subject to scour; this is often best suited for concrete piles, as they can be designed to act as columns if the soil material scours away. The most feasible pile type will be determined during the type selection process, when further geotechnical information is available.

2 documents in project