Study on Numerical Simulation of RC Column Drilling Blasting based on PBM-SPH Coupling Algorithm

Reinforced concrete columns serve as primary load-bearing components in building structures and represent the most frequently encountered demolition targets in blasting projects. Their fragmentation effectiveness directly determines structural instability and the reliability of collapse during demolition. To accurately simulate the complete process of explosive detonation and column fragmentation under borehole blasting conditions, this study employs a PBM-SPH coupling algorithm in combination with 1∶ 1-scale physical modeling. The investigation focuses on explosive detonation dynamics, column fragmentation characteristics, and the flying law of flying stones using the LS-DYNA software calculation platform. Results demonstrate that the Particle Blasting Method(PBM) achieves superior accuracy in simulating explosive detonation dynamics and fragmentation processes compared to conventional Finite Element Methods(FEM). The study reveals the mechanical response mechanism of column fragmentation under varied boundary conditions during borehole blasting. By implementing the SPH algorithm, which discretizes columns into smooth particle flows, this approach effectively addresses traditional FEM limitations in modeling material fracture, fragmentation, and the throwing process. Particle dynamics effectively characterize column fragmentation patterns, yielding more realistic blasting simulation results. The particle migration process accurately models the scattering of flying stones after column blasting, with a particle scattering velocity of 37.7 m/s. Comparative analysis of temporal horizontal displacement data reveals an average simulation error of 8.9%. The PBM-SPH-coupled methodology successfully replicates the complete sequence of explosive detonation and structural fragmentation, providing mechanistic insights for borehole blasting optimization and engineering design refinement.