Optimization Of Wedge Cut Blasting Parameters For Large Section Tunnel

Drilling and blasting method is the main excavation method of traffic tunnel,mining and underground space excavation.Due to the limitation of free surface and space and many other reasons,it is difficult to realize the scientific and refined blasting excavation at present.In the common construction technology of tunnel,the phenomenon of serious over and under excavation,short blasting footage and high single consumption of blasting materials is still prominent;with the great progress of science and technology such as material science and automation technology,large-scale automatic drilling equipment(such as xe3 c automatic three arm rock drilling jumbo)is used instead of manual drilling,digital detonator is popularized and used in tunnel and chamber blasting excavation Roof management and the use of shotcrete and anchor equipment have become the development trend of tunnel construction.How to make full use of the automatic drilling equipment to change the traditional blasting construction method and improve the blasting quality and blasting effect is the main problem in the modern tunnel construction.The investigation found that the current tunnel construction not only failed to give full play to the equipment performance,but also the blasting effect is not as good as that of the manualdrilling.This makes it difficult to popularize the application of automatic drilling equipment in tunnel blasting excavation.In order to solve this problem,we must discuss the blasting parameters matching with the automatic equipment.In tunnel blasting,cut blasting is the core part of the whole blasting.It not only determines the blasting effect,but also controls the cost of blasting excavation.Therefore,the first problem to be solved is to explore the cut blasting parameters matching with automatic drilling equipment.In this paper,based on the Tongzi tunnel project in the expansion of Chongzun expressway,the blasting parameters of medium deep hole wedge-shaped excavation matched with ex3 c automatic three arm rock drilling jumbo are studied,the blasting effect of large section tunnel excavation under various lithology conditions is analyzed by finite element simulation,and the influencing factors of medium deep hole wedge-shaped excavation blasting are analyzed by grey correlation analysis Through the comparative analysis of numerical simulation and field test,the optimal cutting method,delay between cutting rows,blasting footage and other issues are determined.Finally,under the premise of ensuring construction safety,the blasting excavation cost is reduced to the greatest extent,the blasting footage is increased and the blasting efficiency is improved.