上部结构-土-隧道相互作用体系振动台试验模型土的设计与试验研究  

Design and experimental research on model soils used for shaking table tests of superstructure-soil-tunnel interaction system

作　　者：谢军 包淑贤 胡英飞 倪雅静 李延涛 XIE Jun;BAO Shu-xian;HU Ying-fei;NI Ya-jing;LI Yan-tao(School of Civil Engineering and Transportation,Hebei University of Technology,Tianjin 300400,China;School of Civil Engineering,Hebei University of Architecture,Zhangjiakou 075000,China)

机构地区：[1]河北工业大学土木与交通学院,天津300400 [2]河北建筑工程学院土木工程学院,河北张家口075000

出　　处：《岩土工程学报》2020年第3期476-485,共10页Chinese Journal of Geotechnical Engineering

基　　金：河北省科技计划项目(16275406D);河北建筑工程学院研究生创新基金项目(XY202016)。

摘　　要：为使上部结构-土-隧道相互作用体系各部分的加速度相似比相匹配,真实还原地震作用下整个体系的动力响应,采用理论分析和试验相结合的方法,设计了一种以锯末、河砂、粉质黏土以及水为成分的模型土。对试配的不同材料配比的模型土进行了大量30 kPa围压下的共振柱试验,并以此为基础设计进行了正交试验,创建Y(Sγr,Sα,Q)函数以判定模型土与原型土G/Gmax-γ动力特性曲线的相似性。正交试验结果表明:模型土的材料锯末、河砂与粉质黏土最优质量比为18%:27%:55%,含水率为50%;最优方案模型土基本满足了其与原型土加速度相似比Sa等于3、动剪切模量比G/Gmax随剪应变?变化的关系曲线相似的预期目标;并获得了各添加材料对模型土相关动力参数的影响规律。另外,进行了50,70 kPa围压下的最优配比模型土的共振柱试验,验证了其基本满足与原型土在不同围压下G/Gmax-γ动力特性曲线的相似性,同时对比二者的阻尼比?随剪应变?的变化关系曲线,得出二者关于阻尼比的相似性尚可;并基于卓越周期相似分析再次验证模型土与原型土的相似性。研究结论可为今后有关振动台试验模型土的配制提供一定的参考。In order to match the similitude ratio of acceleration of a superstructure-soil-tunnel interaction system and truly restore its dynamic response under earthquake action, a kind of model soil composed of sawdust, river sand, silty clay and water is designed by combining the theoretical analysis with experiments. A large number of resonant column tests on the model soils with different material ratios are carried out at confining pressure of 30 kPa, then the orthogonal test scheme is designed and conducted, and Y(Sγr, Sα, Q) function is created to judge the similitude about dynamic shear modulus ratio-shear strain curves between model and prototype soils. The orthogonal test results show that the optimal mass ratio of sawdust, river sand and silty clay is 18%∶27%∶55%, and the moisture content is 50%. The model soil with the optimal proportion basically satisfies the expected target that its similitude ratio of acceleration to the prototype soil is 3 and its correlation curve of dynamic shear modulus ratio-shear strain is similar to that of the prototype soil. The influence laws about dynamic parameters of model soils are obtained for various additive materials. In addition, the resonant column tests on the model soil with the optimal proportion are carried out at confining pressures of 50 and 70 kPa. It is verified that the similitude between the model and prototype soils at different confining pressures is basically satisfied, their correlation curves about damping ratio and shear strain are compared, and it is obtained that their similitude about damping ratio is reasonable. Based on the similarity analysis of the predominant period, the similitude between the model and prototype soils is verified again. The research conclusions may provide some reference for the preparation of model soils in shaking table tests in the future.

关 键 词：振动台试验 模型土 共振柱试验 正交试验 

分 类 号：TU317.1[建筑科学—结构工程] P315.93[天文地球—地震学]