Omega Pile Installation – 1600 Owens Project
Malcolm Drilling took on the 1600 Owens project, a six-story parking structure in San Francisco’s Mission District. They opted for vibration-free, full displacement Omega pile installation, considering the vertical load requirements exceeding 600 kips. The project presented challenges due to varying soil conditions and bearing layers ranging from 40 to 80 feet below grade, making it challenging to determine the pile lengths in advance.
In lieu of an extensive soil investigation program, Malcolm Drilling decided to use the drill rig’s capability to monitor pile installation in real-time to perform a ‘pile-by-pile’ design. Therefore, a comparison between the soil’s bearing capacity and the required pile Penetration Resistance had to be established. Multiple indicator piles were installed to compare the recorded penetration resistance values with available Cone Penetration Test (CPT) data. The Bauer BG40’s unique on-board monitoring system (B-Tronic) was used to supply various installation parameters and the required QC logs for each pile with real-time data processing. Correlation between the required penetration resistance and the CPT data could then be established. Several static load tests correlated the pile capacities and confirmed the required pile penetration length into the various bearing layers. This approach economized the overall cost by reducing the overall pile length by approximately 20%.