灰土桩复合地基有限元分析

Finite Element Analysis of Collapsible Loess Reinforced by Lime Piles

应用弹塑性有限元方法,研究了灰土桩复合地基受力机理.结果表明:在固结作用最大位移发生在布桩的位置,沿着桩径的增大,位移逐渐减小;桩顶附近的超静孔隙水压力比较大,桩端下地基上中的超静孔隙水压力较小,且沿着桩身长度方向孔压值呈现一种递减的趋势;下卧层和加固层间水压力差逐渐减小,桩间土的有效应力明显小于桩和桩下端土体的有效应力;荷载作用下整个复合地基桩的位移比桩间土位移小,桩左右边界附近均有一定量的隆起,但是隆起量不大,对工程不会造成太大的影响,在地基稳定性的模拟与计算中,桩左右的隆起所产生的影响也是不可忽视的;在荷载作用下桩的有效应力明显大于桩间土的有效应力,在桩头和桩端有明显的应力集中现象,最大有效应力发生在桩端与土体接触的界面附近.

Using elastic-plastic finite element method to study the dust pile composite foundation bearing mechanism.The results showed that：the largest displacement of the consolidation occurred in the pile location,along the pile diameter increases,the displacement decreases; the ultra-quiet pore water pressure that near the top of the pile is quite strong,the ultra-quiet pore water pressure that foundation under the pile in is smaller,and the value of the pore pressure along the pile length presenting a decreasing trend; the water pressure difference between underlying layer and the reinforcement layer decreases,the effective stress of soil in the pile is smaller than the bottom of piles and pile; displacement under load in the composite foundation pile smaller than the soil in the pile,around the boundary of right and left pile has a certain amount of swell,but the value is nor large,will not cause too much influence on the project.in the foundation stability simulation and calculation,the impact of the value of swell can not be ignored; under the load the effective stress of the pile is significantly greater than soil between piles,in the pile head and pile tip stress concentration significantly and the maximum effective stress occurred near the contact surface between pile tip and soil.