Research on Blasting Failure Characteristics and Strain Evolution Law of Bearing Column

In order to analyze the failure characteristics and strain evolution law of reinforced concrete columns after blasting under different amount of explosives per unit area and section stresses, blasting tests of 12 reinforced concrete columns were carried out by using a self-developed test system with uniaxial inertial dynamic loading model, which is based on the theory of elastic mechanics. When the upper section stress of the reinforced concrete columns was 0 MPa, the corresponding amounts of explosives per unit area were 0.11 kg/m², 0.23 kg/m², 0.27 kg/m², respectively. When the upper section stress was 2 MPa, the corresponding amounts of explosives per unit area were 0.13 kg/m², 0.18 kg/m², 0.23 kg/m², respectively. When the upper section stress was 3 MPa, the corresponding amounts of explosives per unit area were 0.18 kg/m², 0.23 kg/m², 0.32 kg/m², respectively. When the upper cross-sectional stress was 4 MPa, the corresponding amounts of explosives per unit area were 0.13 kg/m², 0.18 kg/m², 0.23 kg/m², respectively. In addition, numerical simulation software was used to analyze the impact of different section stresses on blasting effect. The longitudinal central axis crushing distance is defined to describe the crushing range of the column after blasting, and the central axis crushing distance and strain evolution law are analyzed under different influencing factors through theoretical deduction, field experiment and numerical simulation. The analysis results show that with the increase of section stress, the greater the coupling tangential stress close to the central axis, and the coupling tangential tensile stress which is perpendicular to the loading direction is relatively reduced. When the amount of explosive per unit area is less than 0.15 kg/m², the crushing range of the central axis of the column decreases with the increase of the section stress. When the amount of explosive per unit area is more than 0.15 kg/m², with the increase of section stress, the crushing range continues to increase. The peak of tangential tensile strain shows an upward trend, and the absolute value of the peak radial compressive strain gradually decreases. When the section stress is fixed, the crushing range of the column increases with the increase of the amount of explosive per unit area, but the growth rate decreases with the increase of the amount of explosive per unit area. Meanwhile, the peak of the tangential tensile strain of the column increases, and the absolute value of the peak radial compressive strain also shows an upward trend. With the increase of section stress, the crushing range in the column damage cloud is increasing, and the crack tends to extend axially with the load, which further verifies the correctness of the test conclusions.