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.