土体小应变刚度特性的试验研究

Experimental Study of Small Strain Stiffness Properties of Soil

摘要:

土体的小应变刚度在深基坑或隧道开挖等以变形控制为主的工程中是起决定性作用的参数.利用固结仪、应力路径三轴仪和共振柱联合测定江苏常州地区3个典型土层原状土的小应变刚度特性，得到了土体小应变硬化模型(HSS)的相关参数，包括土体的初始剪切模量、模量退化曲线、土体强度参数、加卸载模量等.分析了土体有效应力对土体小应变刚度特性的影响，并对如何选择合适的小应变模型参数提出了初步建议.

关键词:土体刚度; 小应变硬化模型; 固结试验; 三轴试验; 共振柱

Abstract:

Small strain stiffness properties of soil play an important role in predicting the deformation of deep foundation pit and tunnel excavation. This paper used oedometer, stress path triaxial apparatus, and resonant column apparatus to measure the small strain stiffness properties of three typical undisturbed soils in Changzhou, Jiangsu province. The parameters involved in the hardening soil model combined with the small strain model (HSS), including the initial shear modulus, modulus reduction curve, the soil strength parameters, and unloading and reloading modulus, were determined. The influence of effective stress on small strain stiffness properties was also studied, and suggestions were proposed on how to choose suitable small strain model parameters.

Key words:stiffness of soil; small strain hardening model; oedometer test; triaxial test; resonant column