Abstract: Based on the actual condition of engineering, the finite element analysis software PLAXIS is adopted to simulate two different asymmetric excavation conditions of the foundation pit: (1) different excavation depth differences, (2) different excavation interface places. Based on study of practical engineering simulation, with the increase of the excavation depth difference, surface settlement on the two sides both increase; settlement value and effect range on the deep side are also larger than the shallow side. Meanwhile, there is a large diversity deformation of bottom heave on the interface; the deformation difference becomes obvious with the increase of excavation depth difference. With the interface movement to the shallow side, the bottom heave on the deep side tends to be stable; and the variation tendency of the bottom heave increases to the shallow side. Through research, there is a better understanding of characteristic and negative factor of stress and deformation on asymmetric excavation pit, which can guide the construction and control excavation depth difference and interface location of asymmetric excavation, then reduce the engineering risk.

Key words: foundation pit, asymmetric excavation, surface settlement, bottom heave