基于CPTu的状态相关边界面模型标定研究  

The state-dependent bounding surface model calibration based on CPTu data

作　　者：汪明元 孙吉主[2] 王勇[3] 杨洋 WANG Ming-yuan;SUN Ji-zhu;WANG Yong;YANG Yang(Power China Huadong Engineering Corporation Limited,Hangzhou,Zhejiang 310014,China;School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan,Hubei 430070,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;Huadong Engineering(Fujian)Corporation Limited,Fuzhou,Fujian 350003,China)

机构地区：[1]中国电建集团华东勘测设计研究院有限公司,浙江杭州310014 [2]武汉理工大学土建学院,湖北武汉430070 [3]中科院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [4]华东勘测设计院(福建)有限公司,福建福州350003

出　　处：《岩土力学》2023年第11期3280-3287,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51979269)。

摘　　要：对土工结构进行数值分析时,需要引入土的有效应力本构模型,以预测土体变形或液化破坏。然而,由于土单元初始状态的不确定性和缺乏适当的试验结果,模型参数标定经常成为实际工程应用的障碍。在现有边界面模型中引入状态相关的剪胀性概念,使得土体破坏时处于临界状态。基于现场孔压静力触探试验(piezocone penetration test,简称CPTu)的测试数据,提出了模拟单调和循环荷载下土体液化和破坏的边界面模型的参数标定方法。取现场残余强度为室内试验的临界状态,用于标定临界状态线相关参数。基于现有CPTu数据的抗液化强度图,以及震级比例系数与液化等效循环次数之间的联系,建立了土体液化应力比与等效循环次数的关系,在此基础上简要介绍了标定卸载体积模量参数的方法。最后基于CPTu实测地层数据,具体说明了模型相关参数的标定过程。When soil structures are analyzed with numerical method,effective stress-based nonlinear soil models are used to predict soil deformation or liquefaction.However,model parameter calibration often becomes an obstacle to the practical applications of the model because of the uncertainties and lack of appropriate laboratory test results.In this paper,the state dependent dilatancy concept is incorporated into the existing bounding surface model,it makes soil's failure conform to critical state.Based on the piezocone penetration test(CPTu)results,a procedure is proposed to calibrate a bounding surface model for simulating liquefaction and ultimate failure under monotonic or cyclic loading.The in situ residual strength is utilized as critical state obtained from laboratory tests,it is used to calibrate the parameters related to critical state line.A relationship between soil liquefaction resistance and equivalent number of cycles is developed based on published CPT-based liquefaction triggering charts,together with correlations between a magnitude scaling factor and number of equivalent cycles to liquefaction,further the procedure is introduced to calibrate unloading plastic modulus simply.Based on the profiles of piezocone penetration test,examples to illustrate the calibration procedure of the model parameters are presented finally.

关 键 词：孔压静力触探 边界面模型 状态相关 残余强度 参数标定 

分 类 号：TU443[建筑科学—岩土工程]