双向简谐波荷载作用下群桩的力学性状分析

Mechanical characteristics analysis of multi-pile foundations under two-way simple harmonic loads

为研究双向简谐波荷载作用下群桩的力学性状及其受力性能,采用PLAXIS有限元软件建立相应的数值模型,分析了群桩基础在双向简谐波荷载作用下内力、位移响应情况,探究了桩周土体的动应力应变关系,进而对其在循坏水平荷载作用下的受力性能进行探讨。研究结果表明,与水平静载作用相比,桩基在循坏水平荷载作用下的承载能力有所降低;桩顶荷载-位移曲线出现"滞回圈",基桩产生"疲劳效应";桩周土抗力的变化使得各排桩内力分配不均匀;桩周土体的动应力应变关系呈现滞后性、非线性及累积性。

In practical engineering, multi-pile foundations are subjected to （significant） cyclic lat- eral loads. In this research, a numerical model of multi-pile foundation subjected to two-way sym- metric harmonic loads was established via PLAXIS finite element software to investigate the interac- tion （effect） between the internal force and the displacement and the lateral bearing capacity of the foundation. The lateral bearing capacity slightly decreased compared to that in static load with a hys- teresis loop-like load-displacement curve. The stiffness of multi-pile foundation （groups） reduced, and the displacement of soil in the pile group accumulated gradually with the internal forces of each pile row distributing unevenly. The results indicate that all the phenomena can be attributed to the swaying motion of the pile cap induced by two-way symmetric harmonic loads.