深部重塑土高压应力路径试验研究

Study of the Stress Paths Tests for the Deep Reconstituted Soils at High Pressure

为了获取高压条件下应力路径对深部土力学特性的影响,采用自行设计的室内高压试验方法研究了深部重塑土在K0固结基础上4种典型应力路径下的应力-应变行为和强度特性.结果表明:三轴压缩路径下的应力-应变曲线形态呈应变软化型,三轴拉伸路径下的应力-应变曲线则由线性段和应变硬化段组成;三轴压缩路径下深部重塑土的屈服强度和屈服变形均大于三轴拉伸路径,而抵抗破坏的能力刚好相反,且加荷条件下深部土抵抗破坏的能力高于卸荷条件.深部重塑土的室内高压试验应根据工程实际选取合理路径以避免重大事故的发生.

The stress-strain behavior, and strength properties of reconstituted deep soils were studied to evaluate the effect of stress path on mechanical properties. An independently designed high pressure laboratory test method was used to study K0 consolidated soils under four representative stress paths. The results show that triaxial compression causes strain softening.The triaxial decompression stress-strain curves may be divided into a linear and a strain hardening stage. Yield stresses and strains are larger under compression loading than they are under decompression un-loading. Resistance to fracture shows the opposite behavior. Resistance to fracture is greater during compression than it is during decompression. The appropriate stress path must be chosen for laboratory experiments on deep, reconstituted soils to avoid project accidents.