初始主应力方向角对黄土动变形特性影响研究  

Effects of initial angles of principal stresses on dynamic deformation properties of loess

作　　者：王志杰[1,2] 骆亚生[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100 [2]亚琛工业大学岩土工程研究所,德国亚琛52074

出　　处：《地震工程与工程振动》2013年第1期184-191,共8页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(50578134);教育部新世纪优秀人才支持计划项目(NECT-06-0864)

摘　　要：建筑物和构筑物地基土体的主应力方向往往发生旋转,因此研究初始主应力方向角对黄土动变形特性的影响规律具有一定的现实意义。通过对不同初始应力状态下原状与重塑黄土进行动扭剪三轴试验,研究了初始主应力方向角对黄土动变形特性的影响规律,结果表明:在不同初始主应力方向角下,原状黄土抵抗剪切变形的能力大于重塑黄土;在其他条件相同的情况下,初始主应力方向角越大,黄土抵抗剪切变形的能力越弱;随着初始主应力方向角的增大,黄土的动剪切模量随动剪应变变化的规律呈现出减小的变化趋势,而阻尼比则呈现出增大的变化趋势;初始动剪切模量与最大动剪应力随初始主应力方向角的增大而减小。建议在初始平均主应力较大的情况下,考虑初始主应力方向角对黄土动变形特性的影响,试验成果可为黄土地区工程设计提供一定的参考。The principal stress orientations of the soil mass of the foundations under buildings and structures are always rotated. Therefore, conducting research on the effects of initial angles of principal stresses on loess dynamicdeformation properties is practically significant. Dynamic torsional shear triaxial tests were carried out on undisturbed and remodeled loess under different initial stress states. Influencing laws of initial angles of principalstresses on loess dynamic deformation properties were investigated. Results showed that capacities of resisting shear deformations of undisturbed loess are higher than that of remodeled loess under different initial angles of principalstresses. Under the same other conditions, the bigger the initial angles of principal stresses, the weaker the capacities for resisting shear deformations are. The changing laws of dynamic shear moduli of loess versus dynamicshear strains show a decreasing trend with increasing initial angles of principal stresses; while the changing laws of damping ratios show an increasing trend. Initial dynamic shear moduli and maximum dynamic shear stressesdecrease with increasing initial angles of principal stresses. Therefore, the effects of initial angles of principal stresses on loess dynamic deformation properties should be taken into consideration under the condition of largeinitial average principal stresses. The test results could be used as a reference for project designs in loess areas.

关 键 词：黄土 初始主应力方向角 动剪应力-应变关系 动剪切模量 阻尼比 动变形特性 

分 类 号：TU444[建筑科学—岩土工程] P315.93[建筑科学—土工工程]