Proceedings - 13th International Workshop on Micropiles - 2017, Vancouver, BC, Canada, (ISM, DFI, ADSC)
USE OF HIGH CAPACITY MICROPILES TO RESIST SEISMIC OVERTURNING OF COLUMNS
Peter Speier, P.E.
As a result of California State Law enacted in 1994, Sharp Memorial Hospital in San Diego, CA required an extensive seismic retrofit in order to remain in service past January 1, 2015. When built in 1972, the structure was founded on spread footings below the core columns. While these footings remain in service to support static dead loads and live loads, high capacity micropiles were needed to resist overturning moments that would occur at the base of the columns in a seismic event. Rather than tying the micropiles into the existing footings, the micropiles were anchored directly to the retrofitted column base plates. Complicating the installation was the fact that the hospital needed to remain fully operational throughout the entire construction. Not only were the micropiles to be installed in severely limited access conditions, complex management of phase construction, dust control, and spoils management were required to comply with the hospitalís infection control policy. This paper will discuss the complex nature of this project in further detail. Additionally, it will highlight the benefits of how partnering between Contractor, Owner, Engineers, and manufacturers resulted in an efficient, safe, and cost effective solution to an extremely difficult foundation problem.
|article #2626; publication #1033 (ISM- 2017)|