Research on Optimization of Blasting Parameters and Over-Excavation Control of Peripheral Holes in Jointed Rock Mass Tunnel
The existence of joints has a huge impact on the control of tunnel blasting over-under-excavation,based on the Cidu Tunnel,the blasting data of the surrounding holes on the site were collected,the parameters of the peripheral holes of the tunnel were optimized when the joint inclination angle was 60°,and the two tunnel models before and after optimization were numerically simulated by software to analyze the damage and over-under-excavation of the blasted rock mass.The on-site blasting test was carried out,and the total station was used to measure the over-excavation amount of the tunnel after blasting to verify the correctness of the numerical results.The test results show that the blasting effect of the optimized perimeter hole is better,the over-excavation amount of the tunnel is obviously controlled,the average over-excavation amount of the upper step section is reduced by65.25%,and the average unit consumption of explosives is reduced by 13.1%.This study provides a method support for the precise control of over-excavation of jointed rock mass tunnels,and has engineering guiding significance.
jointed rock mass tunnelover-excavationparameter optimizationon-site test
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