Installing Omega Piles at Data Centers.
Malcolm Drilling was awarded the design build contract to install a foundation system for the Terremark Data Center in Santa Clara, CA.. This new facility was constructed within the existing footprint of a concrete tilt up building next to an operational data center. The roof of the concrete tilt up was removed and the walls were internally and externally braced during construction. To develop and support the pile design, Cone Penetration Tests (CPT’s) were performed within the building footprint. Due to the variable soils conditions, all CPT’s were conducted in a grid pattern to determine the pile depth across the site. Based on the soil profile generated by the data collected from the CPT’s, a preliminary pile design was proposed. This design was verified with two compression load tests within the building foot print. Once the test program was accepted, the production piles were installed using the machines on-board automatic monitoring system.
All OMEGA piles were installed using a Bauer BG-28 drill rig equipped with an 18 inch full displacement auger tool. The test program included two compression pile tests, one to a depth of 30 feet and to a maximum compression test load of 350 Kips, and the second to a depth of 54 feet and to a maximum compression test load of 750 Kips. Test piles were not instrumented with tell tales or strain gauges. Only pile head deflection was measured. Both test results exceeded the load carrying expectation of the soil and allowed for design modification. Skin friction values were revised but end bearing was not evaluated since no detailed test data was available. The cooperation between owner and contractor allowed for a quick and effective re-design of most of the production piles within one week allowing production work to start as scheduled. Pile length savings of almost 15% were realized.