砂土与EPS颗粒混合的轻质土的动剪切模量衰减特性分析  

Study on degradation behavior of dynamic shear modulus for lightweight sand-EPS beads soil

作　　者：王庶懋[1] 高玉峰[1] 

机构地区：[1]河海大学岩土工程研究所,南京210098

出　　处：《岩土力学》2007年第5期1001-1004,1014,共5页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.50479020);江苏省青蓝工程资助项目(2006)

摘　　要：动荷载下砂土与EPS颗粒混合的轻质土(LSES)的割线剪切模量Gsec随着剪应变的累积会发生衰减,基于不同水泥掺量和EPS含量的LSES试样的动三轴试验结果,建立了与围压、剪应变、水泥掺量等因素相关的Gsec的经验衰减模型。通过比较发现,LSES与砂及胶结砂的Gsec衰减模型具有一定相似性,即Gsec与γd呈双曲线关系,与σc为指数关系。此外,由于水泥胶结的约束作用,Gsec对σc的依存度随水泥掺量的增加而减小,这种依存程度通过参数n反映出来,但当水泥掺量达到10%时n随其的变化就不明显了,这是因为胶结强度已经增大到使得LSES中颗粒间的相对位置不易发生错动的程度。The secant shear modulus of lightweight sand-EPS beads soil （LSES） under dynamic loads will degrade with increasing strain. Based on cyclic triaxial test data on LSES of different cement contents and EPS contents, a degradation model of Gsec is set up relating to factors such as confining pressure, shear strain and cement content. After comparison, the Gsec model of LSES is similar with those of sand and cemented sand, that is, Gsec-γd is hyperbolic and Gsec is linear to σc. Additionally, due to the bonding effect of cementation, the confining pressure dependency of Gsec decreases with increasing cement content, which is responded by the parameter n. While cement content reaches to 10 %, the variation of n is not clear. This is because cementing strength increases to the level which makes the relative location between particles of LSES uneasy to change.

关 键 词：砂土与EPS颗粒混合的轻质土 割线剪切模量 衰减特性 

分 类 号：TU435[建筑科学—岩土工程]