Bridge Driveway Underpinning in Alamo, CA
Challenge
According to the Soils Report that was done for this home, the bridge that served as the driveway for this home was experiencing an erosion of the soil near the grade beams that supported the wood columns that held up the bridge. This was due to a clogged drain inlet that caused the ravine beneath the bridge to flood for a long period of time. Most of the work we do involves installing push piers directly beneath the foundation of a home. Installing push piers to lift and stabilize a driveway bridge was something we had never encountered before.
Solution
Our solution was to install 15 Push Pier 288s, 5 of which had HA175 Helical Piers and Lateral Restraints installed from the outer edge of the grade beams into the center of the soil beneath the bridge. Each push pier was hydraulically pressed into the earth to an average length between 22 to 25 feet where they met resistance and the bedrock/strata where the load of the bridge would be transferred from the settling grade beams. Now the homeowner can live better knowing that his driveway bridge is stabilized and safe.
