孔隙水压力静力触探动态贯入过程的有限元模拟

The FEM simulation of dynamic penetration process of CPTU

孔隙水压力静力触探作为一种新型的土体勘测技术已被广泛应用,但是,其机理的研究尚存在很大的不足。笔者系统分析了孔压触探的贯入特征,提出了“孔隙水压力体积基准值”的概念,借此推导出用土体体积变形量计算超孔隙水压力的公式。在此基础上,用轴对称有限单元法模拟探头的动态贯入过程,揭示应力-应变的变化特征,寻找超孔隙水压力生成与消散的规律,对孔压触探的机理进行了研究。

As a new kind of investigating and testing technology of soils,Piezocone Penetration Test(CPTU)has been used widely.But there is insufficient in its mechanism study.In this paper,the characteristics of penetration process of CPTU were analyzed,and the concept of 'volume base value of pore water pressure'was put forward,by which the formula of calculating the excessive pore water pressure with the volume deformation value of soil was deduced.Based on these,the axisymmetric finite element method is used to simulate the process of the cone dynamic penetration in soil,in order to disclose the features of strain and the stress developing,look for the regulation of the generation and dissipation of the excessive pore water pressure,and study on the mechanism of Piezocone Penetration Test.