干密度对预剪应力下重塑黄土动力特性影响的试验研究

Experimental Study on the Effects of Dry Density on Dynamic Properties of Remodeled Loess under Condition of Pre-shearing Stress

摘要:

干密度是岩土工程建设中重要的控制指标。本文以不同干密度与不同初始平均主应力状态下重塑黄土为对象,通过进行主应力轴旋转(α0=45°)产生预剪应力条件下的动扭剪三轴试验研究,得出:干密度对预剪应力条件下重塑黄土动剪切模量的影响较小,而初始平均主应力对其有一定的影响;在其他条件相同时,动剪切模量与初始动剪切模量分别随干密度与初始平均主应力的增大而增大;阻尼比随动剪应变的增大先减小而后缓慢增大;干密度与初始平均主应力对重塑黄土阻尼比的影响不明显。

Abstract:

Dry density is an important controlling index of the geotechnical engineering constructions.With different dry densities and different initial average principal stresses,the dynamic torsional shear triaxial tests are carried out on remodeled loess under the condition of pre-shearing stress,which is produced by rotation of principal stress axes（α0=45°）.Research results show that the dry density has little effect on the dynamic shear modulu of remodeled loess under the condition of pre-shearing stress.Initial average principal stress has some certain effect on the modulu.If other conditions being the same,the dynamic shear modulu and initial dynamic shear modulu increase with the increase of dry density and initial average principal stress.The damping ratios of remodeled loess first decrease with the increase of the dynamic shear strain and then increase gradually.The effects of dry density and initial average principal stress on damping ratio of remodeled loess are insignificant.