NUMERICAL SIMULATION OF THE EFFECT OF BLASTING LOAD ON EXISTING UNDERGROUND CONSTRUCTION

摘要

An analytical solution and simplified design procedure is presented for evaluating the dynamic response of existing chamber subjected to blasting seismic. Based on the practical project, dynamic finite element and wavelet packet transform methods are used together to study its seismic effect, it is a effective method for us to master the propagation mechanism of blasting vibration and energy laws. In this paper, dynamic effect of blasting vibration on underground construction is simulated through dynamic finite element program, in which ALE and Lagrange arithmetic are coupled. The velocity field, displacement field and stress field in the surface of existing chamber are obtained. On the base of simulation results, "db4" wavelet in the MATLAB wavelet toolbox is used in the compiled program to analyze energy and frequency of the vibration, and blasting energy visual distribution map in time-domain and frequency-domain is gained. The numerical simulation results prove its precision by comparing with field measured data. The results from this article provide valuable understanding of the effect of blast on existing underground structure, and will be helpful in design of blast as well as for developing protective retrofits for existing underground structures.