线性扰动条件下饱和土体扩张计算分析

Calculation and Analysis of Soil Expansion with Linear Disturbance

针对饱和软土扩张时土体易受扰动的问题,通过引入扰动系数描述扰动程度,在塑性区内通过线性插值给出了不同位置处土体屈服准则,并基于不排水条件推导了扩张过程中的应力分布,采用Henkel孔隙水压力理论给出了扩张后超孔隙水压力分布规律,对比分析了不同扰动程度下的扩张结果。试验结果表明:(1)外部作用对土体的扰动主要体现为对土体结构性的影响,具体体现为土体强度的降低,塑性区内扰动程度随距离的增大而降低,在塑性区半径处扰动程度降低为0;(2)不考虑扰动情况下的计算结果会偏大,不利于工程安全性评价,考虑扰动的影响更加符合工程实际情况,结果更合理。

Aiming at the problem that the soil is easy to be disturbed when expanding in saturated soft soil,the disturbance coefficient is introduced to describe the degree of disturbance.In the plastic zone,the yield criteria of soil at different positions are given by linear interpolation,and the stress distribution in the expansion process is deduced based on the undrained condition.The distribution law of excess pore water pressure after expansion is given by using Henkel pore water pressure theory.The expansion results under different disturbance degrees are compared and analyzed.