Study On Dynamic Load Of Blasting Demolition Of Frame Structures Under Different Blasting Partitions

With the progression of blasting demolition technology,it was widely used in urban building demolition project,from multi-layer to high-level,from a single structure to the composite structure,Meanwhile the surrounding environment is more complex and harsh,Such as proximity of the building(structure)only allow the collapse in a small range,a variety of dense underground pipelines and developed transport lines.These harsh surrounding environmental conditions impose higher and finer requirements on blasting technology.This paper,use the concrete frame structure of the building as research object,lists the classification of frame structure building and the collapse mode of blasting demolition;enumerated the general calculating method of the critical blasting and use the test data of Xiangxiang City to analysis the advantages and disadvantages of the methods.Analysis the mechanics and the dynamics of the collapse process.Through the analysis of force situation of the remaining support parts,unblocked posts and the beam structure,We established Dynamic load coefficient P_S,and the calculation formula of the maximum dynamic load of the column under the condition of different partition initiation conditions.Based on the explosive demolition engineering about the main building of bus station at Xiangxiang City,six detonation formulations are proposed employing ANSYS/LS-DYNA,where the solid element SOLID164 is adopted.Investigating the axial force of upright columns and shear force and bending moment of beam-type structures,coefficient PS of impact load is verified and the function which calculates the maximum impact load of residual columns under different detonation conditions is modified.Result reveals that collapse process of main building derived from numerical simulation has good agreement with that occurs in practical engineering,which validates the present numerical modelling.It is found that triangle blasting incision is more appropriate than rectangular blasting incision for simulating the damping of buildings.