The deformational machanism of deepexcavation in soft clay is that the deformation of the pit is induced by unloading and plasticdeformation of the soil mass.

• 软土基坑的变形是由于基坑开挖后卸荷回弹及应力重分布后土体的塑性变形所致，变形类型包括侧向位移、坑底隆起和地表沉降三个方面，三者之间存在着体积上的联系。