夹硬层土中单桩贯入挤土效应的数值模拟

桩贯入土体产生的挤土效应问题较为复杂。利用ABAQUS软件建立了单桩贯入夹硬层土和均质土的二维轴对称有限元模型，经过分析比较，得出了单桩贯入夹硬层土体所特有的位移场及应力场的变化规律。分析表明：桩贯入夹硬层土过程中，软硬土层交界处土体水平位移变化剧烈；硬土层的存在，会使土体水平及竖向位移受到约束；夹硬层土的水平挤压应力要远大于均质土情况；与水平应力相比，竖向挤压应力在硬土层处明显偏小。

Squeezing Effect of Pile in Hard Layered Soil

The squeezing effect of the pile penetration into soil is complicated. 2-dimensional axisymmetric finite element model is established with ABAQUS software for the pile penetration into hard layered soil and homogeneous soil. By the analysis and the comparison, the variation laws of special displacement field and stress field of single pile penetration into hard layered soil are obtained. The analysis shows that in the process of pile penetration into hard soil, the horizontal displacement dramatically changes between hard and soft soil layer junction. In hard soil layer, the horizontal and vertical displacements are limited, the horizontal compressive stress is obviously larger than in homogeneous soil; compared with horizontal stress, the vertical compressive stress is obviously smaller.