高速公路碎石桩复合地基加固数值模拟

通过数值模拟分析了高速公路碎石桩复合地基在桩体施工、路堤填筑、运行期全过程和地震动荷载等作用下的受力问题。计算结果表明:碎石桩在路堤的填筑和运行期中起到明显的排水固结作用,当桩长大于6m后复合地基中的孔压最大值变化较缓慢;在桩长大于10m后路堤底面的沉降量和坡脚的水平位移量变化均会较小。地震荷载作用下路堤顶部的水平向加速度峰值较底面更大;在碎石桩加固范围内,复合地基的水平刚度大于天然地基,而在整个地基内,复合地基的竖向刚度均大于天然地基,在地基刚度较大的情况下位移最大值较大;天然地基在路堤坡脚下方、路堤边坡等位置较易发生液化,经过碎石桩加固后降低了地基液化的可能性。

Numerical Simulation of Stone Columns Reinforced Foundation of Expressway

A numerical analysis is studied on the construction,runtime and earthquake condition of stone columns reinforced foundation.Calculation results indicate that: the stone columns has a significant effect on drainage of excess pore pressure under construction and runtime,when pile length is larger than 6 m,maximum pore pressure changed slowly,when pile length is larger than 10 m,settlement developed under embankment and horizontal displacement developed under slope toe changed slowly.Under earthquake the maximum acceleration on top of the pave is larger than bottom of the model;in reinforced scope,horizontal stiffness of composite foundation is larger than natural foundation,in the whole foundation,vertical stiffness of composite foundation is larger than natural foundation,maximum displacement is larger in large stiffness foundation;toe position and slope of embankment is more liquefied under earthquake,but stone column composite foundation can reduce liquefaction possibility.