砂土应力-应变包络线的唯一性初探  

Preliminary study on uniqueness of stress-strain envelope curves of sand

作　　者：邵龙潭[1,2] 高睿 夏平心 郭晓霞[1,2] 孙衍朴 SHAO Longtan;GAO Rui;XIA Pingxin;GUO Xiaoxia;SUN Yanpu(State Key Laboratory of Structural Analysis for Industrial Equipment,Dalian University of Technology,Dalian 116024,China;Department of Engineering Mechanics,Dalian University of Technology,Dalian 116024,China;Department of Civil Engineering,Changzhou University,Changzhou 213164,China)

机构地区：[1]大连理工大学工业装备结构分析国家重点实验室,辽宁大连116024 [2]大连理工大学工程力学系,辽宁大连116024 [3]常州大学土木工程系,江苏常州213164

出　　处：《岩土工程学报》2025年第2期265-274,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(52079018,4240070651);常州领军型创新人才引进培育项目(KYZ23020054)。

摘　　要：土体循环加卸载外包络线是否具有唯一性在认识土体固有属性上具有重要意义。基于土样全表面变形数字图像测量系统,选用硅微粉和福建标准砂为研究对象,开展了一系列三轴剪切试验和三轴循环加卸载试验,探索等应力幅值、阶梯应力幅值和随机应力幅值循环加卸载下应力-应变外包络线与相应的单调加载应力-应变曲线的一致性。试验结果表明土样在相同密度和围压条件下,单调加载的应力-应变曲线与经历不同循环应力历程的加卸载应力-应变外包络线近似一致,提出了砂土应力-应变外包络线的唯一性;讨论了循环应力历史和应力水平对曲线回归速度的影响以及应力-应变包络线唯一性在建立轴向应变累积模型中的应用。The uniqueness of the stress-strain envelope curves of sand under cyclic unloading is of great importance in understanding the inherent properties of the sand.A series of monotonic triaxial compress tests and cyclic triaxial tests,considering constant amplitude,step stress amplitude as well as random stress amplitude,are conducted on the silica powder and Fujian standard sand to explore the consistency between the stress-strain envelope curves and monotonic curve by employing the full-surface digital image measurement system.The results show that the monotonic stress-strain curves of the soil samples with the same density and confining pressure are approximately consistent with the stress-strain envelope curves that undergo different cyclic stress processes,and the uniqueness of the stress-strain envelope curves of the sand is proposed.The influences of the cyclic stress history and stress level on the regression velocity of the curves and the application of the uniqueness of the stress-strain envelope curves in the establishment of the axial strain accumulation model are discussed.

关 键 词：应力-应变外包络线 循环荷载 砂土 轴向累积应变 

分 类 号：TU43[建筑科学—岩土工程]