静三轴试验中水泥土力学特性及本构模型研究  

Study of mechanics behavior and constitutive model of cemented soil under static triaxial tests

作　　者：王军[1] 丁光亚[1] 潘林有[1] 蔡袁强[1] 高玉峰[1,2] 

机构地区：[1]温州大学建筑与土木工程学院,浙江温州325035 [2]河海大学岩土工程科学研究所,南京210098

出　　处：《岩土力学》2010年第5期1407-1412,共6页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.50808145;No.50979096;No.50778136);浙江省自然科学基金项目资助项目(No.Y1090105);浙江省建设厅科研项目(No.08Z027);浙江省高校优秀青年教师资助计划项目

摘　　要：通过不排水三轴压缩试验对水泥土的力学特性进行研究,重点分析了围压与水泥掺入比对水泥土体强度、孔压及刚度的影响。试验结果表明,随着围压与水泥掺入比的增加,水泥土体的强度与刚度均增加,而孔压随之减少;随着轴应变的增加,刚度逐渐减少。而在加载初期,刚度衰减较快,随着轴应变的继续增加曲线渐趋平缓,衰减现象并不明显;随着无量纲化偏应力的增加,无量纲化刚度逐渐减少,并且两者为曲线关系。通过对水泥土的刚度软化规律进行描述,得到了修正的邓肯-张模型。通过对试验曲线进行回归分析确定了模型参数。与实测数据对比发现,该修正模型不仅可以较好地模拟水泥土的应力-应变关系,还体现了水泥土应变软化型曲线的特点。Undrained triaxial compressive tests were carried out on cemented soil to investigate the effects of confining pressure and cement ratio on the strength,pore water pressure and stiffness of cemented soil.It was observed that with the increase of confining pressure and cement ratio,the strength and stiffness increase and pore water pressure decreases.The stiffness decreases as the axial strain increased.The stiffness decreases greatly at the beginning of the tests and then the stiffness curves become smooth with a small degradation rate with the increase of axial strain.The relationship between normalized deviator stress and stiffness shows a nonlinear.With the increase of the normalized deviator stress,the normalized stiffness decreases.The stiffness degradation behavior of soft clay was described and Duncan-Chang model was modified.The parameters for modified Duncan-Chang model were obtained by regression.The comparison of simulation results with test data shows the modified model can simulate the strain-softening stress-strain relations of cemented soil.

关 键 词：水泥土 强度 孔压 刚度 本构模型 

分 类 号：O319.56[理学—一般力学与力学基础]