【摘要】 利用土工静力-动力液压三轴-扭转多功能剪切仪,对黄河三角洲埕北海域原状粉土试样进行了循环三轴和循环扭剪试验,以此探讨了原状海底粉土的动力变形与强度特性,确定了最大动剪切模量及动力变形参数随剪应变的变化规律。基于循环三轴试验结果,建立了残余孔隙水压力发展变化规律的双曲线经验模式,对动强度关于循环次数的依赖性提出了经验关系,确定了有关试验参数及其关于固结应力比的依赖性。与循环三轴试验结果相对比,认为在土工抗震设计中采用循环三轴试验结果稍偏于保守。更多还原

【Abstract】 The soil static and dynamic universal triaxial and torsional shear apparatus was employed to perform both undrained cyclic triaxial tests and cyclic torsional tests for undisturbed silty soil samples.Based on the experimental test results,dynamic characteristics of both deformation and strength of undisturbed marine silty soil is investigated.The maximum dynamic shear modulus and the dependency of dynamic shear modulus and damping ratio on shear strain are defined through cyclic triaxial shear tests.An empirical pattern is established for residual pore water pressure generated during cyclic shear which is represented by a hyperbolic function with respect to the number of cycles of dynamic stress.And an empirical formula is developed to describe the cyclic strength with respect to the number of cycles.The related parameters involved in both patterns of pore water pressure and cyclic strength are determined by experimental tests;and their dependency on the consolidation stress ratio is clarified.The experimental data achieved from cyclic torsional shear tests are used to validate the results from the triaxial shear tests.It should be more conservative using the cyclic strength determined by triaxial shear tests in geotechnical earthquake design.更多还原