桥体爆破拆除塌落冲击对土体影响深度的计算方法

Calculation method of soil collapse impact influence depth of bridge blasting demolition

为确保建筑物拆除爆破时地下各类管线的安全,以漳州东立交桥整体爆破拆除工程为背景,将桥体爆破拆除时的塌落对土体的作用过程类比为强夯,基于强夯理论提出建筑物塌落冲击对土体的影响深度以及土体沉降值的计算方法。采用PLAXIS和ANSYS/LSDYNA分别对漳州市东立交桥逐跨塌落进行数值模拟,根据塑性区的范围和土体的位移大小判断影响深度。最后将数值模拟和现场实测数据与建立方法的计算结果进行对比分析,证明计算方法的可行性。研究成果可以为类似工程及相关研究提供参考。

In order to ensure the safety of all kinds of underground pipelines in the building blasting demolition, the blasting demolition project of Zhangzhou east overpass was taken as the background. The collapse effect of the bridge demolished by blasting was analogous to dynamic compaction. Based on the theory of dynamic compaction, the calculation formula of the soil influence depth and soil settlement value was put forward. PLAXIS and ANSYS LS-DYNA were used to numerically simulate the collapse of Zhangzhou east overpass span by span. According to the range of plastic zone and the magnitude displacement of the soil, the effect depth was judged. Finally, the numerical simulation, the field test data and the result of calculation methods were compared and analyzed. The method was proved feasible. It could provide a reference for similar projects.