去除非有效段桩侧阻力的静载试验隔离措施

ISOLATION METHOD OF WIPING OFF UNEMPLOYED SEGMENT PILE SHAFT RESISTANCE IN STATIC LOAD TEST

当单桩静载试验存在较长的非有效段时,需要采取有效措施去除非有效段桩侧摩阻力,以求得在实际工作标高上的单桩承载特性。结合北京地区某工程测试实例,说明通过双套筒法可以有效地去除非有效段桩侧摩阻力,并与实际工程桩的测试结果进行对照分析,表明直接应用试桩结果存在一定风险,需要在实际工程设计的应用中考虑上覆土层对测试结果的影响。

In pile static load test, effectual isolation method must be adopted to wipe off the unemployed segment pile shaft resistance in order to get the bearing characteristics of a single pile at the actual working elevation, when there is a relatively long unemployed pile segment. It is illustrated with an engineering test example in Beijing that double steel casing method is an efficient way to wipe off the unemployed segment pile shaft resistance. Farther, by comparing the tested result of the work pile, it shows that there will be a risk in directly applying the test result data in project, and the effect of overburden on thee test results should be considered in pile foundation design.