摘要
在土中掺入一定量的胶结物形成具有显著结构性的人工胶结土,被广泛应用于天然岩土体的改良。然而,结构性的存在往往会诱发胶结土相较重塑土呈现出更为复杂的力学特性,实现其力学行为的定量化分析及合理预测十分必要。此处针对胶结土力学行为的共性问题,开展了不同初始状态水泥胶结土的三轴压缩与剪切试验,系统分析了其力学特性的状态相关性,并采用状态相关模型开展其力学行为的计算预测。结果表明:(1)胶结土的峰值剪切应力比受初始状态量(孔隙比、围压、胶结性)的影响显著,而残余剪切应力比受初始状态量的影响较小,表明残余强度可作为一个状态无关的力学特性参数;(2)胶结土的等向压缩曲线受初始状态量(孔隙比、胶结性)的影响显著,但结构性损伤使得压缩曲线会逐渐向重塑胶结土压缩曲线趋近,表明重塑胶结土压缩曲线可作为固有压缩曲线;(3)通过计算能够较好地再现上述不同初始状态胶结土的等向压缩与三轴剪切试验结果,表明所采用的状态相关本构模型能够合理地描述胶结土的复杂力学行为。
Mixing soil with a certain amount of binding agent can form artificial cemented soil with remarkable structure,which is widely used in the improvement of natural geomaterials.However,the existence of structure often induces cemented soils to appear more complex mechanical characteristics than remolded soil,and it is necessary to achieve quantitative analysis and reasonable prediction of their mechanical behaviors.This paper focuses on the common mechanical characteristics of cemented soil,the triaxial compression and shear tests of cement-bonded soil with different initial states are carried out,and then the state dependence of its mechanical characteristics is systematically analyzed.Finally,the state-dependent model is used to calculate/predict its mechanical behavior.The research results show that:(1)The peak shear stress ratio of cemented soil is significantly affected by its initial state(void ratio,confining pressure,cementation),while the residual shear stress ratio is less affected by the initial state,indicating that the residual strength can be used as a state-independent mechanical parameter;(2)The isotropic consolidation curves of cemented soil is significantly affected by the initial state(void ratio,cementation),but the damage of structure makes these compression curves gradually converge to that of remolded cemented soil,indicating that the consolidation curve of the remolded cemented soil can be used as the inherent compression curve;(3)The isotropic compression and triaxial shear test results of the above-mentioned cemented soils with different initial states show an encouraging agreement with date by calculation,indicating that the state-dependent constitutive model here can reasonably describe the complex mechanical behavior of cemented soil.
作者
陆勇
冯海华
朱文轩
周亚
叶冠林
Lu Yong;Feng Haihua;Zhu Wenxuan;Zhou Ya;Ye Guanlin(School of Civil Engineering,Suzhou University of Science and Technology,Suzhou,Jiangsu 215011,P.R.China;School of Naval Architecture,Ocean&Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,P.R.China;ZYF Construction Group Co.,Ltd,Suzhou,Jiangsu 215131,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2024年第5期1541-1554,共14页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(52331010,42207220)
江苏省高等学校基础科学(自然科学)研究项目(22KJB170020)。
关键词
胶结土
力学特性
状态相关性
本构模型
cemented soil
mechanical characteristic
state-dependency
constitutive model
