Application Research On Mechanized Drilling-blasting Method Construction Technology And Equipment Of Highway Tunnel In Weak Surrounding Rock

With the rapid development of the tunnel industry and the continuous innovation of science and technology,highway tunnel construction is gradually moving towards mechanization and automation.However,the proportion of weak surrounding rock in China's highway tunnels is not small.Its construction mode is still based on a large number of artificial.According to the technical characteristics to drilling and blasting construction of highway tunnel in weak surrounding rock,the applicability as well as choosing and matching problems can be studied and solved.The problem is about engineering mechanical equipment of drilling and blasting construction series.This can promote the construction of highway tunnels in the weak surrounding rock areas.It can also improve the technical level of drilling and blasting construction in soft surrounding rock about highway tunnel.Firstly,the development of highway tunnel construction in weak surrounding rock at home and abroad was analyzed.In addition,the equipment selection and construction characteristics of tunnel drilling and blasting under different surrounding rock conditions were analyzed.Tthrough the comparative study on artificial and mechanical method,the applicability and technical requirements in construction of mechanical drilling and blasting method in weak surrounding rock tunnel were analyzed.Based on the analysis of the highway tunnel construction technical requirements,the mechanized drilling and blasting construction scheme was proposed according to the working mode that using bench method in weak surrounding rock.In this scheme,the main construction equipment is the jumbo with full hydraulic of domestic to match the steel arch assembly trolley.Practical research on mechanical drilling and blasting based on project shows that the method is feasible in highway tunnel construction for weak surrounding rock.Secondly,the paper proposed a drilling and blasting construction method of highway tunnel which was suitable for evaluating the tunnel construction in weak surrounding rock.It is called GRA-AHP comprehensive evaluation method.The comprehensive evaluation method includes four indicators,which are progress,quality,cost and safety.And the construction schemes of different tunnel drilling and blasting methods were comprehensively evaluated by Grey Relational Analysis and Analytic Hierarchy Process.Finally,the practical application research of mechanized drilling and blasting construction for more than 500 meters was carried out based on the project.The application experience of drilling and blasting construction mechanical equipment was summarized,and the improvement measures were put forward.According to the comprehensive evaluation method proposed in this paper,the statistical data of test tunnels can be analyzed.It was calculated that mechanized construction was superior to manual work in terms of progress,quality and safety.With the increase of labor cost and the decrease of the price in domestic mechanical equipment,the cost that mechanized and manual construction have been relatively close.It shows that the comprehensive evaluation of mechanized drilling and blasting is superior to artificial.