爆破技术在城市基坑工程中的应用越来越广泛，但爆破活动对邻近设施和环境可能产生一定的扰动，在爆破施工时产生的振动作用会影响基坑支护结构的力学响应规律，这关系到基坑工程的安全与稳定。运用数值模拟的研究方法，借助ANSYS/LS-DYNA有限元软件，基于青岛齐鲁医院二期基坑开挖工程的相关参数，建立基坑开挖三维模型，通过调整各炮孔爆破时的间隔时间，分析不同微差条件下岩质基坑爆破施工过程中岩石的破碎情况与支护结构的动态力学规律。结果表明：当炸药起爆存在微差时，炮孔周围岩石中的裂纹长度更加发育，岩体中粉碎区的面积也随之增大。与无微差爆破情况相比，桩体上所测得的有效应力与振动速度曲线在微差逐孔起爆时表现出更为分散的波动特征，出现多组波峰，并未形成应力波的叠加效应。微差爆破可有效提高破岩效果并减低爆破振动对钢管柱的影响。

Blasting technology is more and more widely used in urban foundation pit engineering, but blasting activities may cause certain disturbance to neighboring facilities and environment, and the vibration generated during blasting construction will affect the mechanical response law of foundation pit supporting structure, which is related to the safety and stability of foundation pit engineering. The numerical simulation research method and finite element software ANSYS/LS-DYNA were used to establish a three-dimensional foundation pit excavation model based on the relevant parameters of the second phase foundation pit excavation project of Qingdao Qilu Hospital. By adjusting the blasting interval of each gun hole, the dynamic mechanical laws of rock breakage and support structure during blasting construction of rock foundation pit under different differential conditions were analyzed. The results show that when there is a slight difference in explosive initiation, the crack length in the rock around the gun hole is more developed, and the area of the crushing zone in the rock mass is also increased. Compared with non-differential blasting, the effective stress and vibration velocity curves measured on the pile show more scattered wave characteristics, and there are multiple groups of wave peaks, and the superposition effect of stress waves is not formed. Differential blasting can effectively improve the rock breaking effect and reduce the effect of blasting vibration on steel pipe column.