土体动剪切模量及其衰减特性现场试验研究  

Field experimental study on dynamic shear modulus of soil and its decay characteristics

作　　者：王艳芳 顾伟杰 姜彦彬 WANG Yanfang;GU Weijie;JIANG Yanbin(Jinling Institute of Technology,Nanjing 211169,China;Shandong Yellow River Reconnaissance Design&Research Institute Co.Ltd.,Jinan 250013,China)

机构地区：[1]金陵科技学院,江苏南京211169 [2]山东黄河勘测设计研究院有限公司,山东济南250013

出　　处：《世界地震工程》2022年第3期144-152,共9页World Earthquake Engineering

基　　金：国家自然科学基金青年科学基金项目(51908278);江苏省高校自然科学基金面上项目(19KJD410002);金陵科技学院高层次人才科研启动项目(jit-b-202017)。

摘　　要：如何获取土体动模量原位衰减曲线是研究天然土层在循环动荷载下的动变形特性课题中亟待解决的难题。为此,本文自制了一套地震动参数现场试验系统,依据动剪切模量原位测试原理获得了不同深度土体在小应变范围内的动模量原位衰减曲线。试验数据表明:当剪应变小于4×10^(-5)时,土体变形处于线性阶段;当剪应变大于4×10^(-5)时,土体归一化动剪切模量G/G_(max)衰减加快,以塑性变形为主。同时,当向土层施加的垂向静荷载越大,归一化动剪切模量值G/G_(max)与对数剪应变值logγ_(d)之间的关系会逐渐上移,但直线段斜率值不变。相关成果可为试验场地的动模量取值提供一定参考。How to obtain the in-situ decay curve of soil dynamic modulus is a pressing problem in the study of the dynamic deformation law of natural soil layers under cyclic dynamic loading.In this connection,a set of field test system for ground motion parameters was made in this paper,and the principle of in-situ testing of dynamic shear modulus was used to obtain the in-situ decay curves of dynamic modulus of soils at different depths in a small strain range.The test data shows that when the shear strain is less than 4×10^(-5),the soil deformation is in the linear stage;when the shear strain is greater than 4×10^(-5),the decay of the normalized dynamic shear modulus G/G_(max) of the soil accelerates and plastic deformation dominates.Meanwhile,the relationship between the normalized dynamic shear modulus value G/G_(max) and the logarithmic shear strain value logγ_(d) gradually shifts upward when the vertical static load applied to the soil layer is larger,but the slope value of the linear segment remains unchanged.The related results would provide a certain reference for the value of the dynamic modulus of the test site.

关 键 词：动剪切模量 剪应变 现场试验 地震动参数现场试验系统 衰减特性 

分 类 号：TU4[建筑科学—土工工程]