含黏粒砂土动力特性试验研究

为研究含黏粒砂土的动力特性,使用GDS共振柱试验仪器,以青岛地区典型含黏粒砂土为原型,利用福建标准砂和马来西亚高岭土配置试样,进行饱和排水试验,分析动剪切模量、阻尼比随动应变的变化规律及其影响因素。实验结果表明:含黏粒砂土G-γ曲线、D-γ曲线形状与无黏粒砂土类似,动剪切模量随动应变的增加而减小,阻尼比随动应变的增加而增加。对比发现,相同干密度条件下,对应同一动应变,含黏粒砂土围压越大,动剪切模量越大,阻尼比越大;无黏粒砂土围压越大,动剪切模量越大,阻尼比越小。相同围压及干密度条件下,含黏粒砂土的动剪切模量要小于无黏粒砂土,阻尼比要大于无黏粒砂土。

Experimental Study on Dynamic Properties of Clayey Sand

In order to study the dynamic properties of clay-bearing sands, GDS resonant column instrument was used to test the dynamic shear modulus and damping ratio. The typical clayey sand in Qingdao area was taken as prototypes. Fujian standard sand and Malaysian Kaolin soil were used to make samples to conduct saturated drainage tests. The variation of dynamic shear modulus and damping ratio with dynamic strain and their influencing factors were analyzed. The experimental results show that, the shape of G-γ curves and D-γ curves of clayey sand are similar to that of non-clayey sand. The dynamic shear modulus decreases with the increase of dynamic strain, and the damping ratio increases with the increase of dynamic strain. Under the same dry density, for the clay-bearing sand, the greater the confining pressure, the greater the dynamic shear modulus and the greater the damping ratio would be. For the non-clayey sand, the greater the confining pressure, the greater the dynamic shear modulus and the smaller damping ratio would be. Under the same confining pressure and dry density, the dynamic shear modulus of clay-bearing sand is smaller than that of non-clayey sand, and the damping ratio is larger than that of non-clayey sand.