Installing Cased Drilled Shafts for the Cypress Avenue Bridge Replacement
For this project, Malcolm Drilling was contracted to perform the cased drilled shaft work for the Cypress Avenue bridge replacement over the Sacramento River in Redding, California. In total, 28 drilled shafts, 8 feet in diameter and up to 92 feet deep, were required. Due to large cobbles and boulders with diameters up to 2 feet, the installation of a temporary casing was the only viable option. Malcolm employed one of its large oscillator machines to install heavy-duty Leffer casing for the full shaft depth. Near the river banks, work was performed on rock pads, while most of the shafts were installed from a temporary steel trestle. In addition to concrete integrity testing of each shaft, one full-scale load test was performed ahead of construction using the Osterberg Load test method. Exceptionally good test results enabled the reduction of individual shaft lengths, which resulted in overall cost savings for the entire project.
