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.

In blasting demolition projects of housing buildings, reinforced concrete columns serve as the primary load-bearing structural elements and consequently represent the most frequently targeted components for controlled demolition. The effectiveness of reinforced concrete column demolition through blasting operations plays a pivotal role in ensuring structural instability and controlling the overall collapse mechanism. The evolution of modern reinforced concrete columns, characterized by increased cross-sectional dimensions, higher reinforcement densities, and enhanced material strengths, has significantly elevated the technical complexity of the design of blasting parameters and the protection of flying rocks. The Particle Blasting Method coupled with the Finite Element Method(PBM-FEM) was employed to simulate the dynamic process of explosion impact loading and explosion gas escaping from the borehole through the high-speed motion collision of particles. Full-scale 1:1 physical model tests were conducted using industrial electronic detonators to accurately replicate the blasting demolition process of high-rise building structural members. The research reveals critical insights into the failure mechanisms and damage propagation characteristics of reinforced concrete columns under controlled demolition conditions. The results show that the explosion gas escapes from the orifice and reduces the utilization rate of explosive energy due to the limited constraint effect of the blocking material on the side of the blast hole. The severity of concrete spalling on the surface of the column is left and right sides > front side > back side. The direction of the minimum resistance line is the main direction to induce concrete damage and throwing.

In order to solve the problem of blasting demolition of tall reinforced concrete water towers in restricted space, a vertical in-situ blasting demolition technology was developed. The impact failure mechanism, collapse process and touchdown vibration of the water tower were analyzed comprehensively by means of high-speed photography, vibration monitoring and numerical simulation. It was found that the collapse process of the tower by vertical in-situ blasting demolition is similar to free fall motion with an acceleration of 9.4 m/s² calculated by regression analysis, which was slightly smaller than the gravity acceleration. By using the “separated” finite element model, the collapse process of the water tower could be approximately simulated and the impact time of each section cylinder could be accurately captured. In general, cumulative damage by multiple impacts is the main characteristic of the complex failure process of the water tower, which can be simulated by the No. 159 concrete material model. The main frequency band of the vibration is mainly concentrated in the range of 5~60 Hz. The high frequency part of the vibration signal attenuates rapidly, and the energy is mainly concentrated in the low frequency part. Moreover, the total energy of the vibration signal decreases significantly with the increase of distance. The test results show that the successive vertical collapse of the tower and the simultaneous blasting on the top water tank can control not only the collapse range of the tower, but also the touchdown vibration and blasting dusts.

With the increasing complexity of the urban environment and environmental awareness of the public, directional toppling blasting demolition of frame structure buildings often encounters the problems of large collapse recoil distance and strong ground impact vibration, which limits the development and application of blasting demolition technology. To control the collapse recoil and touchdown vibration of the directional blasting demolition of the frame structure building, the design method of the hinge point forward high blasting cutting was put forward, and the theoretical calculation model of blasting cutting height was established based on traditional bottom cutting blasting demolition technology. Meanwhile, a blasting demolition technology of high-cutting blasting with a reserved buffer layer was developed combined with engineering practice. Three kinds of blasting cutting forms were designed to meet the control requirements of different degrees of collapse recoil and touchdown vibration according to the treatment method of the reserved buffer layer. Furthermore, the collapse and disintegration effects of frame structure blasting demolition in different blasting schemes are compared and analyzed by theoretical analysis, numerical simulation, and field test. The results show that the hinge point forward high blasting cutting can increase the inclination angle, prolong closure time, and control the structure’s collapse recoil and touchdown vibration, greatly improving the reliability of structural instability and collapse. Compared with the traditional bottom-cutting blasting scheme, the reserved buffer layer hinge point forward high-cutting blasting scheme can effectively shorten the length of the blasting pile, reduce the speed of structural collapse to the ground, and effectively control the height of the blasting pile. The selection of a reserve buffer layer should be considered comprehensively with the structural characteristics of the building and the surrounding environment.