胶结砂砾石坝坝料双屈服面弹塑性本构模型研究  

Study on elastoplastic constitutive model with the double-yield surface of cement-sand-gravel material

作　　者：江敏敏 李文伟 向欣 郭兴文[2] 蔡新[2] JIANG Minmin;LI Wenwei;XIANG Xin;GUO Xingwen;CAI Xin(China Three Gorges Corporation,Beijing 100038,China;College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 211100,Jiangsu,China)

机构地区：[1]中国长江三峡集团有限公司,北京100038 [2]河海大学力学与材料学院,江苏南京211100

出　　处：《水利水电技术（中英文）》2023年第3期96-104,共9页Water Resources and Hydropower Engineering

基　　金：国家重点研发计划项目课题(2018YFC0406804);国家自然科学基金重点项目(U2040222)。

摘　　要：【目的】为了准确预测不同胶结材料用量及围压下胶结砂砾石料的应力变形特征,【方法】采用理论推导与试验结果分析相结合的方法,在广义塑性位势理论框架下,依据胶结砂砾石料力学特性三轴试验结果,构建了新的剪切屈服函数和体积屈服函数。结合可反映硬化规律的塑性系数以及加卸载准则,建立了一个双屈服面本构模型,随后对比分析胶结材料用量20 kg/m^(3)、60 kg/m^(3)以及100 kg/m^(3)的胶结砂砾石料三轴剪切试验数据及本构模型的计算值。【结果】研究结果表明,抛物线型剪切屈服函数与椭圆型体积屈服函数可很好地反映胶结砂砾石料的剪切变形与体积变形机制。【结论】新的本构模型充分考虑了胶结材料用量、围压对胶结砂砾石料塑性变形、峰值强度、剪胀性等特性的影响;模型参数共有12个确定简单且物理意义明确的参数;该双屈服面本构模型的应力应变预测值与相应的三轴试验数据基本吻合。[Objective]In order to accurately predict the stress and deformation characteristics of cemented sand gravel(CSG)under different amount of cemented materials and confining pressure.[Methods]A new shear yield function and volume yield function is constructed by combining theoretical derivation with test result analysis under the framework of generalized plastic potential theory and based on the triaxial test results of mechanical properties of CSG.Combined with the plastic coefficient that can reflect the hardening law and the loading and unloading criterion,a double yield surface constitutive model is established.Then,the triaxial shear test data and the calculated values of the constitutive model of CSG with the amount of cemented material of 20 kg/m^(3),60 kg/m^(3)and 100 kg/m^(3)are compared and analyzed.[Results]The results show that the parabolic shear yield function and elliptic volume yield function can well reflect the shear deformation and volume deformation mechanism of CSG.[Conclusion]The new constitutive model fully considers the effects of the amount of cemented material and confining pressure on the plastic deformation,peak strength and dilatancy of CSG.There are 12 parameters with simple determination and clear physical meaning.The predicted values of stress and strain of the dual yield surface constitutive model are basically consistent with the corresponding triaxial test data.

关 键 词：胶结砂砾石料 胶结材料用量 双屈服面 弹塑性模型 

分 类 号：TU411[建筑科学—岩土工程] TV321[建筑科学—土工工程] TV649[水利工程—水工结构工程]