固原重塑黄土动力特性共振柱试验研究

Resonance Column Tests on the Dynamic Characteristics of Remolded Loess in Guyuan

摘要:

利用GCTS共振柱测试仪研究了干密度和固结压力对固原黄土重塑土动剪切模量和阻尼比的影响及试验数据误差的基本规律。通过设计不同工况的试验条件，对比分析结果表明：相同含水率条件下，最大动剪切模量G_dmax随固结压力和干密度的增大而增大。相同干密度条件下，黄土的动剪切模量比随围压的增大而增大；阻尼比随围压的增大而减小；相同围压条件下，黄土动剪切模量比随干密度的增大而增大，阻尼比随干密度的增大而减小；不同剪应变特征点的动剪切模量比和阻尼比试验数据呈现一定的离散性，且离散程度阻尼比明显高于动剪切模量比。研究成果可为该地区场地地震反应分析及工程建设提供基础资料。

Abstract:

Dynamic shear modulus and damping ratio are important indicators in characterizing the mechanical properties of soil under the action of an earthquake. The influences of dry density and consolidation pressure on the dynamic shear modulus and damping ratio of remolded loess in Guyuan, and the basic rule of the error of test data were studied by the GCTS resonant column apparatus. The comparative analysis results under different test conditions indicated that the maximum dynamic shear modulus increases with increasing consolidation pressure and dry density under constant moisture content. Under the same dry density, the dynamic shear modulus ratio of loess increases and the damping ratio decreases with increasing confining pressure. Under the same confining pressure, the dynamic shear modulus ratio of loess increases and the damping ratio decreases with increasing dry density. The test data of dynamic shear modulus ratio and damping ratio of different shear strain points showed a certain discreteness, and the discrete degree of the damping ratio was obviously higher than that of the dynamic shear modulus ratio. The research results can provide basic information for local seismic response analysis and engineering construction.