Liquefaction Mitigation using Vertical Composite Drains: Full-Scale Testing for Pile Applications. Highway IDEA Program

摘要

This follow-on activity to a previous NCHRP-IDEA project (NCHRP-94) involved full-scale field tests to evaluate the liquefaction mitigating effect of vertical composite drains for pile applications. Work in the first phase focused on site characterization and blast testing in an untreated area. A pattern of small explosive charges was established for detonation to simulate the liquefaction process produced by an earthquake, and pilot tests were performed with various charge weights and delays to better simulate the duration and intensity of an earthquake and to determine the energy required to induce liquefaction. The field tests were performed at a site near Vancouver, British Columbia. The tests also included pile load testing before and after blast testing in areas treated and untreated with drains. The field test results were complemented with modeling analysis to determine likely pore pressure response in the area treated with drains. The test results and modeling analysis verified the effectiveness of the proposed approach.