Simulation Study On Excavation Footage Level Of Drilling And Blasting Method In Rock Roadway Based On System Dynamics

Rock excavation is one of the important links in coal production,and the efficiency of rock excavation affects the mining speed of coal.How to improve the rock excavation footage has become a difficult problem that the coal industry needs to study and solve.Therefore,it is of great practical significance and social value to improve the rock excavation speed for realizing a stable coal supply.This study aimed to solve the problem of how to scientifically improve the footage of the rock excavation using the drilling-blasting method.Firstly,the literature on the related research and theory of rock excavation was reviewed.Secondly,a model for the footage level of rock excavation using the drilling-blasting method was established based on the theory of system dynamics,the key loop affecting the excavation footage was obtained by the simulation analysis of the model,and based on this loop,the measures for optimization and improvement were suggested.Finally,an optimization scheme was put forward and tested in the actual rock excavation,and the prediction results of the model were compared with the test results.As a result,the effectiveness of the model for the footage level of the rock excavation using the drilling-blasting method is verified,thereby providing reference for the rapid rock excavation and its system management.The main results of the study are described below.Based on the analysis of the factors affecting the footage of the rock excavation using the drilling-blasting method,a CIA-ISM model for the footage level of rock excavation using the drilling-blasting method was established by using the combination of the cross-impact analysis and the interpretative structural modeling method.The model results show that the natural environment is the fundamental factor that affects the excavation footage,which is followed by the construction process and technical methods;the poor matching between the natural environment and the machinery and tooling is the main cause that leads to the failure of the machinery and tooling,and such failure is the most important factor that leads to a low rock excavation footage and prolonged excavation time.Based on the qualitative and quantitative analysis of the rock excavation system using the drilling-blasting method,an SD-based model for the footage level of Rock excavation using the drilling-blasting method was established with Gubei Coal Mine as the background.The analysis results of the model show that,among the five subsystems,the environmental factor has the greatest effect on the excavation footage,and the excavation footage is the most sensitive to the variable of single cycle time,followed by the variables of personnel experience and technical capability.Finally,with the variable of single cycle time as the starting point,the optimal path and countermeasures for improving the footage level of rock excavation using the drilling-blasting method were analyzed and obtained.Based on the optimization path obtained from the SD model mentioned above,taking the actual engineering project as the research object,an optimization scheme was put forward based on the on-site attendance records and discussion with the on-site technicians.By optimizing the key construction machinery,the cut blasting technology and the initiating device,the new scheme was tested.The test results showed that,compared with the original construction scheme,the single cycle time was reduced by11%,the blast hole utilization rate was increased by 15%,and the monthly footage was improved by 33%.The comparison between the SD model prediction results and the field test results shows that the model can accurately predict the results of the optimization scheme,which is of practical guiding significance to the rock excavation construction.