SuperPile 2017 Online Proceedings, (DFI)
Yucca Loma Bridge Drilled Shaft Foundation Piles
Rick Walsh, P.E., G.E. and Chuck Danache
The Yucca Loma Bridge project is located in Apple Valley, California. The foundations for the bridge include: 12 ea. abutment shafts, 72" dia., and 48 ea. pier shafts 120" dia. Working grade elevations were up to 20' above the pile cutoff elevations, with groundwater approx. 5' below existing grade. Pile tip elevations were approximately 115' below the existing ground surface. The project required that the first two 120" diameter CIDH production pier shafts were to be tested with Osterberg Cells (O-Cells). Each of these load tests required O-cells with a test capacity of 8,400 kips. After installation and testing of the load test piles, Hayward Baker continued installation of the production piles. Once concrete in the load test shafts attained the required strength, load tests were conducted. The results of this testing verified the original design and allowed optimization of the design, resulting in a shortening of the remaining production piles of approximately 13. This resulting pile shortening included a deductive change order for the decreased length as well as shortening the work schedule. The O-Cell testing had an overall impact of verifying the design parameters utilized. The deductive change order was in an amount exceeding the cost of the testing. Other non-destructive testing required for all piles included the Mini Shaft Inspection Device, SoniCaliper, and Gamma-Gamma testing. All shafts were evaluated with the SoniCaliper and Gamma-Gamma testing. The SoniCaliper is used to provide a profile of the shaft, including the verticality and shape of the shaft sidewalls. Gamma-Gamma testing is used to evaluate the drilled shaft concrete for any potential anomalies. Based on the SoniCaliper testing, very few shafts required remedial work to remedy slightly out of tolerance verticality that included a small amount of sidewall shaving. The Gamma-Gamma testing did not indicate any anomalies requiring remediation. The Mini SID was conducted on the first 5 shafts and then was discontinued after testing results indicated very clean shaft bottoms with the methodologies employed by Hayward Baker. Foundation Drilling article regarding project attached. Project has not been previously presented at any industry event.
|article #2692; publication #1031 (SP-2017)|