膨胀土及其改良土静动力特性对比分析

研究了膨胀土及其改良土的基本物理性质，进行了膨胀土的静动三轴试验。通过资料对比，发现膨胀土的静应力-应变曲线呈硬化型，改良土的呈软化型，改良土的静强度和粘聚力比膨胀土的大：发现两类土的动应力都存在一个门槛值，由此将土体的变形分为稳定型及破坏型，得到了累积塑性变形与循环荷载次数间的关系表达式：还研究了两类土的骨干线、动弹性模量-动应变曲线的变化规律，未发现动荷载频率对土体变形有显著影响。

DYNAMOSTATIC ANALYSIS OF PROPERTIES OF EXPANSIVE SOIL AND IMPROVED SOIL

The physical properties of expansive soil and improved one are researched, and the dynamostatic triaxial tests are made on the two kind of soils. Compared with the other material, it is found that the stress-strain curve of expansive soil behaves as strain hardening, while that of improved expansive soil behaves as strain softening. The static strength and cohesion of improved expansive soil are bigger than that of expansive soil. There is a threshold of dynamical stress which divides the deformation of soil into steady-state deformation and destructive-state deformation for the two kinds of soils. The experimental formula between the cumulative plastic strain and the number of cycles of dynamic load is set up, and the dynamical stress-strain curve and dynamical elastic modulus-elastic strain curve for two kinds of soil are also studied. According to the testing results, it is not found for the frequency of dynamical load to affect the deformation of soils obviously.