裂隙性黄土在减压三轴压缩下的变形破坏特征

Deformation and failure characteristics of fissured loess under decompressed triaxial compression condition

为了研究黄土地区各种开挖工程所引起的土体变形乃至破坏现象,通过对裂隙性黄土样进行减压三轴压缩试验,得到其应力应变关系曲线,总结了裂隙性黄土的变形破坏特征。试验结果表明:减压三轴压缩试验下,裂隙性黄土的应力应变曲线以近似理想塑性或软弱化型为主,随着轴向压力的增大,其软化现象越明显;其总体变形方式为轴向变形和侧向弯曲变形;当土样裂隙角度为45°,60°时,容易沿原裂隙发生剪切破坏。

For studying the loess deformation and failure characteristics induced by engineering excavation,we studied the failure characteristics of fissured loess by the decompressed triaxial compression test and obtained the stress- strain curve. The summarization of the deformation and failure characteristics of fissured loess shows that the stress- strain curve of fissured loess is strain- soften type or approximately perfect plasticity,the softening phenomenon turns to be obvious with increase of axial stress,the deformation type is mainly axial and lateral bending deformation; the shear deformation is prone to occur along the original fissure when the fissure angles is 45° or 60°.