不同细粒含量饱和粉土动力特性及微观结构研究

Study on dynamic property and microstructure of saturated silty soil with different fine grained contents

本文针对不同细粒含量的杭州饱和粉土动力特性进行了研究,并对土的微观结构进行测定,用以探究粉土的强度、动剪切模量和微观结构的关系。研究结果表明,当粉粒含量不变而粘粒含量在8%~15%之间变化时,动强度会随粘粒含量的增高呈现抛物线型变化,最低点在粘粒含量为12%附近出现;而保持粘粒含量不变,粉粒含量在40%~70%变化时,动强度随粉粒含量变化呈现单一增长。动剪切模量测定结果显示,当细粒含量变化时,最大动剪切模量G_(max)和动强度的变化规律呈正相关关系;通过电子扫描电镜对试样的微观结构进行观察,解释了由细粒含量变化而引起土样动力特性变化的内在原因。

The influence of different fine grained contents on dynamic property of saturated silt soil in Hangzhou area is studied in this paper. The microstructures are measured to determine the relationships among strength, dynamic shear modulus and microstructure. Research shows that if the clay content varies from 8% to 15% with the same silt content, the dynamic strength will be a parabola type with the clay content increases, and the lowest dynamic strength appears at the clay content of 12% ; if the silt content varied from 40% to 70% with the same clay content, the dynamic strength enhances with the silt content increases. According to dynamic shear modulus determination test, the maximum dynamic shear modulus is positively associated with dynamic strength when the fine content changes. The inherent reasons of fine grained content variation leading to the dynamic property＇ s change is explained by electronic microscopy scanning of the microstructures of saturated silt specimen