苏州第四纪沉积土动剪切模量比和阻尼比试验研究

通过深入分析苏州第四纪土的海相、陆相沉积环境及土层分布特征， 对苏州第四纪土 311 个原状土样进行了土的动剪切模量比和阻尼比试验研究 ，结果发现：海侵作用和土层深度对苏州第四纪各类土的动剪切模量比、阻尼比与剪应变幅值关系曲线的影响有明显差异，深度 0 ～ 30 m 的海相黏土动剪切模量比和阻尼比曲线分别低于和高于陆相黏土的曲线，深度 30 ～ 100 m 的海相黏土动剪切模量比和阻尼比曲线分别高于和低于陆相黏土的曲线；土 层深度对海相黏土、粉质黏土和海、陆相粉细砂的动剪切模量比曲线 以及对海相黏土、粉质黏土和陆相粉细砂的阻尼比曲线的影响较为明显；对黏土、粉质黏土、粉土、粉细砂按土层深度 0 ～ 30 m 和 30 ～ 100 m 以及淤泥质土、中粗砂不区分土层深度，给出了苏州第四纪各类土的动剪切模量比和阻尼比曲线经验关系的拟合参数值及其平均关系曲线推荐值。

Experimental study on dynamic shear modulus ratio and damping ratio of Suzhou quaternary sedimentary soil

Based on the comprehensive analysis of the marine and continental depositional environments and distribution characteristics,the comparative experiments are carried out on 311 undisturbed soil samples to study the dynamic shear modulus ratio and damping ratio of Suzhou quaternary sedimentary soils.The results show that the influences of transgression and soil depth are significantly different for various Suzhou quaternary sedimentary soils on the relationship between shear modulus ratio and shear strain as well as between damping ratio and shear strain.The dynamic shear modulus ratio and damping ratio of marine clay at the depth of 0～30 m are smaller and larger than those of continental clay at the same elevation,respectively.However,a contrary relationship exists for the marine clay at the depth of 30～100 m.The depth has a distinct impact on the curves of dynamic shear modulus ratio with shear strain for the marine clay,silt clay,silt sand and continental silt sand as well as on the curves of damping ratio for the marine clay,silt clay and continental silt sand.The fitting parameters and recommended values for the average curves of dynamic shear modulus ratio and damping ratio are given after distinguishing the clay,silt clay,silt and silt sand layers from the depth of 30 m while keeping muddy soil and medium coarse sand as one layer.