Stress-strain curves and outlook change of specimens after test show that specimen failure is of different features according to different confining pressure and initial structures.

• 受土体结构（主要是粗大未全风化的钾长石团斑边缘弱区和残余结构面）和围压条件控制，剪切过程中土体细观损伤呈空洞-裂隙-空洞形式的演化。