Seismic Tests of a Pile-Supported Structure in Liquefiable SandUsing Large-Scale Blast Excitation

摘要

Extensive, large-amplitude vibration tests of a pile-supported structure in a liquefiable sand deposit have been performedrnat a large-scale mining site. Ground motions from large-scale blasting operations were used as excitation forces for vibrationrntests. A simple pile-supported structure was constructed in an excavated 3m-deep pit. The test pit was backfilled withrn100%-water-saturated clean uniform sand. Accelerations were measured at the pile-supported structure, in the sand in therntest pit and in the adjacent free field. Excess pore water pressures in the test pit and strains of one pile were also measured.rnVibration tests were performed with six different levels of input motions. The maximum horizontal accelerationrnrecorded at the adjacent ground surface varied from 20 Gals to 1353 Gals. These alternations of acceleration providedrndifferent degrees of liquefaction in the test pit. Sand boiling phenomena were observed in the test pit with larger inputrnmotions. This paper outlines vibration tests and investigates the test results.