Fitch Avenue over Mint Canyon Wash Bridge Replacement

The Fitch Avenue Bridge over Mint Canyon Wash is located just west of Sierra Highway in the Los Angeles County unincorporated community of Canyon Country. The Fitch Avenue Bridge serves as the only bridged connection to a nearby rural community and plays a critical role during major storm events. The original Fitch Avenue Bridge was built in 1927 as a single span, timber on steel frame superstructure, measuring 20-feet long by 10-feet wide. The bridge was widened and extended several times over the years and in 1963 was expanded to a two-span timber structure measuring 43-feet long by 28-feet wide. Throughout its 88-year life, the bridge survived a number of natural disasters including a fire in 1974 and heavy rains in 1993. The 1993 storms caused scouring of the pier which led to significant vertical settlement. Horizontal displacements of the superstructure also occurred due to debris flows that were much larger than could be passed beneath the bridge. A safe and sustainable bridge that could accommodate the needs of the community and resist the natural disasters that plagued the previous bridge was vital. In 2015, the Los Angeles County Department of Public Works began construction of a single-span reinforced concrete bridge. The replacement bridge consists of a cast-in-place T-beam superstructure measuring 60-feet long by 54-feet wide and is founded on 24-inch diameter cast-in-drilled-hole deep pile foundations. The roadway can accommodate a 12-foot wide traffic lane, 8-foot wide shoulder, and 6-foot wide sidewalk in each direction of travel. A 3-foot tall concrete barrier with attached 4-foot high picket rails line each side of the bridge. Vehicular safety was improved by increasing the load carrying capacity of the bridge to current AASHTO standards and the addition of Caltrans Type 26 concrete barriers that provide greater collision protection. Current Caltrans seismic design standards were utilized to ensure safety and serviceability of the bridge after a maximum credible earthquake. Pedestrian safety was also increased. Residents can now utilize the 6-foot wide ADA accessible sidewalks to cross the bridge instead of walking in the roadway, exposed to traffic. The new 8-foot wide shoulders also provide ample space between cyclists and motorists. The reinforced concrete bridge no longer poses a fire risk in an arid wildfire-prone mountain area. Deep abutment pile foundations provide embedment below the scour depth to protect the bridge from settlement and a raised soffit elevation will allow the flow from a 50-year storm to pass safely beneath the bridge. The new bridge serves a critically important role by providing the only bridged pedestrian, bike, and vehicular traffic ingress and egress route to a rural community. This project has improved the quality of the local roadway system within Los Angeles County. It has enhanced safety, increased mobility, improved a vital emergency disaster route, and enriched the lives of the community.