振动台试验饱和机制砂模型土动力特性研究

Study on dynamic characteristics of saturated manufactured sand model soil for shaking table test

根据饱和砂土-结构相互作用振动台试验的相似性要求,对饱和砂土的相似性要求进行探讨,提出以机制砂作为通用的饱和砂土模型材料。通过动力三轴分级循环加载试验,研究饱和机制砂模型土的最大动剪切模量Gmax、动剪切模量比G/Gmax-γ曲线、阻尼比λ-γ曲线、孔压比ru-ΔW曲线的变化范围,得到其动力本构模型参数随有效粒径d10、不均匀系数Cu、曲率系数Cc和相对密度Dr的变化规律和拟合公式,并根据相似要求和拟合公式分不同情况给出饱和机制砂模型土的配制方法。与文献中多种原型砂土的相似性分析表明,饱和机制砂模型土可以对大部分原型砂土有效实现动力特性相似和液化特性相似,证明其广泛适用性。

According to the similarity requirements of shaking table tests for saturated sand-structure interaction,the similarity of saturated sand was discussed,and the manufactured sand was proposed to be used as the universal model material for saturated sand.Through dynamic triaxial tests,the variation ranges of the maximum dynamic shear modulus Gmax,dynamic shear modulus ratio curve G/Gmax-γ,damping ratio curveλ-γ,and pore pressure ratio curve ru-ΔW of saturated manufactured sand model soil were studied.The variation laws and fitting formulas of the dynamic constitutive model parameters with effective particle size d10,uniformity coefficient Cu,curvature coefficient Cc and relative density Dr were obtained.And then,based on the similarity requirements and fitting formulas,the preparation method of saturated manufactured sand model soil was proposed for different situations.The similarity analysis with various prototype sand in the literatures showed that saturated manufactured sand model soil could effectively achieve similarity in dynamic and liquefaction characteristics for most prototype sand with wide applicability.