饱和黄河岸滩粉土循环荷载后的变形强度特性
发布时间：2019-08-03 07:46
【摘要】：对黄河岸滩饱和粉土在固结不排水条件下进行了一系列单调加载、循环荷载后单调加载的三轴试验,研究了动应力幅值、围压及动孔压比对循环荷载后力学特性的影响,提出了可考虑围压及动孔压比影响的粉土循环荷载后单调加载应力应变关系的变形模式。试验结果表明:循环荷载作用完全液化时,动应力幅值变化对液化后力学特性的影响很小;循环荷载后单调加载的有效应力临界状态线与单调加载时相同,不受循环荷载作用历史的影响。与单调加载时相比,循环荷载后的不排水强度及初始切线模量皆产生衰化,衰化程度随动孔压比的增大而增大,初始切线模量的衰化程度更明显;不同围压下循环荷载后的不排水强度比、初始切线模量比及破坏比,皆与动孔压比之间有良好的归一化关系;粉土循环荷载后的应力应变关系可以用双曲线模型来描述,模型计算值与试验实测值基本吻合。
[Abstract]:A series of triaxial tests of saturated silt on the Yellow River beach under consolidation and undrained conditions were carried out. The effects of dynamic stress amplitude, confining pressure and dynamic pore pressure ratio on the mechanical properties after cyclic loading were studied, and the deformation model of monotone loading stress-strain relationship after cyclic loading of silt considering the effects of confining pressure and dynamic pore pressure ratio was put forward. The experimental results show that when the cyclic load is completely liquefied, the dynamic stress amplitude has little effect on the mechanical properties after liquefaction, and the critical state line of effective stress after cyclic loading is the same as that under monotone loading, which is not affected by the history of cyclic load. Compared with monotone loading, the undrained strength and initial tangent modulus after cyclic loading decay, the degree of decay increases with the increase of dynamic pore pressure ratio, and the decay degree of initial tangent modulus is more obvious, and there is a good normalization relationship between undrained strength ratio, initial tangent modulus ratio and failure ratio after cyclic loading under different confining pressures. The stress-strain relationship of silt under cyclic loading can be described by hyperbolic model, and the calculated values of the model are in good agreement with the measured values.
【作者单位】： 西安理工大学岩土工程研究所;恒大地产集团石家庄有限公司;
【基金】：国家重点基础研究发展计划(973计划,2011CD403305) 陕西省教育厅省级重点实验室重点科研资助项目(2010JS086)
【分类号】：TU411
[Abstract]:A series of triaxial tests of saturated silt on the Yellow River beach under consolidation and undrained conditions were carried out. The effects of dynamic stress amplitude, confining pressure and dynamic pore pressure ratio on the mechanical properties after cyclic loading were studied, and the deformation model of monotone loading stress-strain relationship after cyclic loading of silt considering the effects of confining pressure and dynamic pore pressure ratio was put forward. The experimental results show that when the cyclic load is completely liquefied, the dynamic stress amplitude has little effect on the mechanical properties after liquefaction, and the critical state line of effective stress after cyclic loading is the same as that under monotone loading, which is not affected by the history of cyclic load. Compared with monotone loading, the undrained strength and initial tangent modulus after cyclic loading decay, the degree of decay increases with the increase of dynamic pore pressure ratio, and the decay degree of initial tangent modulus is more obvious, and there is a good normalization relationship between undrained strength ratio, initial tangent modulus ratio and failure ratio after cyclic loading under different confining pressures. The stress-strain relationship of silt under cyclic loading can be described by hyperbolic model, and the calculated values of the model are in good agreement with the measured values.
【作者单位】： 西安理工大学岩土工程研究所;恒大地产集团石家庄有限公司;
【基金】：国家重点基础研究发展计划(973计划,2011CD403305) 陕西省教育厅省级重点实验室重点科研资助项目(2010JS086)
【分类号】：TU411
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