桩-液化土相互作用p-y曲线修正计算方法研究

利用大型振动台桩–土–承台试验,以API规范为基础,提出可液化土层中桩基动力p–y曲线双参数修正方法及修正计算公式,解决目前API规范折减系数法计算可液化土层中桩基动力p–y曲线不符合实际、工程设计上难以接受的问题。采用4种不同密度可液化砂土层等幅波振动台试验,以砂土密度作为主要控制因素,对API规范计算公式中土体初始模量和极限土阻力这两个参数进行修正,提出修正系数。采用地震波输入大型振动台桩–液化土–承台相互作用试验进行验证,结果表明所提修正公式与试验结果较为符合。修正公式保留了API规范的基本模式,修正系数表达简单明了,物理含义明确,具备工程应用前景。

Modified calculation method of p-y curves for liquefied soil-pile interaction

Based on the API code, the double-parameter modified method and the revised computational formula for lateral dynamic p–y curves of pile foundation in liquefiable soil layers are presented by using pile-soil shaking table tests, and as a result, the unacceptable problem of the current coefficients for calculating the dynamic p-y curves by the API code in engineering practice can be solved. Using four different densities of liquefiable sand layers in the shaking table tests by incident sinusoidal waves and taking the sand density as a major factor, the initial modulus and ultimate soil resistance parameters in the API code are modified. Using shaking table tests on pile-soil liquefaction interaction by incident irregular seismic waves the modified method and the revised computational formula are verified. It is indicated that the modified method and the revised formula are agreeable with the test results. The expression of the revised formula is as simple as that in the API code and is convenient for practical engineering application.