Research on numerical simulation of jointed steel plates parameters optimizationin single-walled wall under blasting impact

In order to improve the utilization rate of the section of the deep shaft, a new single-layer shaft wall with jointed steel plates has been invented. In blasting excavation, the phenomenon of concrete cracking and leakage in the adjacent area to the joint steel plate often occurs.In this paper, the numerical simulation method was used to analyze the coupling interaction between the steel plate and the concrete.The simulation results show that there are 4 vibration strengthening zones in the wall of each mold well,sorted from strong to weak, the outer concrete of vertical steel plate > the concrete at the interface of shaft wall and rock wall > the upper concrete of inclined steel plate at the bottom of each mold > the lower concrete of inclined steel plate at the top of each mold, this conclusion is applicable to the same type of shaft wall. Considering the damage and plastic strain of concrete in the above-mentioned areas, the optimum thickness of vertical plate of the background steel is 8 mm, the maximum damage value of the concrete is 6.0%, and the damage ratio accounts for 0.57% of theconcrete.The above quantitative results are influenced by rock properties, blasting scheme, geometric size of shaft lining structure and strength grade of concrete. The geometrical dimensions of the borehole structure and the strength grade of the borehole concrete, the research method has applicability in the same type of borehole wall structure. The thickness of the vertical steel plate of the background engineering is optimized, and the phenomenon of cracking and seepage of the concrete wall is greatly reduced, and the quality of the project is good.