杭州海积软土应力–应变特征与结构强度损伤规律研究

STUDY ON STRESS-STRAIN CHARACTERISTICS AND DAMAGE RULE OF STRUCTURAL STRENGTH FOR MARINE SOFT SOIL IN HANGZHOU

杭州海积软土是结构性土,其结构效应十分显著。海积软土在剪切试验中只产生剪缩现象,且其应力–应变曲线总体上呈一种特殊的应变硬化型,因而不同于典型的应变软化型结构性土。通过求取海积软土先期固结应力和结构屈服应力,得出了软土结构强度随埋深的变化规律以及软土在单向压缩条件下随压力的损伤规律,由此较好地实现了结构性土结构强度的求取,明确了结构强度的概念。

Previous laboratory testing studies showed that marine soft soil in Hangzhou is a structural soil, which has obvious structural effect. But in this research, shear shrink phenomenon of the marine soft soil is only observed in shear tests, and the stress-strain curve of the marine soft soil is of hardening of special pattern. These two characteristics differ from typical strain softening of structural soil, so it can be concluded that marine soft soil in Hangzhou is a special structural soil. The pre-consolidation pressure and structural yield stress of the soil are obtained, the rules of structural strength varying with cover depth and damage rules under varying uniaxial compressive pressure are determined. Then, the calculation of structural strength of structural soil is optimized, and the concept structural strength is clarified.