Study On Quality Variation And Control Of Initial Support Quality Of Highway And Mountain Tunnels In Qinba Mountain Area Under Complex Geological Conditions

With the rapid development of modern transportation,the number of tunnel construction has also increased significantly,and the quality of tunnel construction has received great attention.As an important part of tunnel construction,initialsupport determines the quality of the project to a large extent.At present,the research on the quality of tunnel engineering is being carried out extensively.Although there are many researches on the initial support of tunnels,they are all specific researches on a certain construction link.There is less research on the overall quality control of initial support,and there is a lack of a set.Comprehensive quality management system integrating quality variation analysis,quality control and quality assessment.In this context,this paper studies the analysis and control system of the initial support quality variation of tunnels.The paper uses the Yinbai Expressway opened tunnel as the actual engineering background,and studies the quality variation and control of the initial support of the tunnel.The main research is as follows:Firstly,in-depth understanding of the geological conditions of the Qinba Mountain area and the initial support characteristics of the tunnel in conjunction with the Qinba Mountain Area,where the Chengkai Tunnel is located,combined with the existing engineering experience and research results,studied the quality control indicators of the initial support of the tunnel and established quality control.The index system adopts the coefficient of variation method to statistically process the data of each control index of the supporting project,analyzes the initial variation of the quality of the support and the specific variation degree of each control index,and then obtains the influencing factors of the initial support quality variation of the tunnel.Secondly,through the variation analysis,the factors affecting the initial support quality of the tunnel are obtained,and these factors are taken as the quality process control indicators,and the evaluation parameters are selected for each index,and then the quality process control index system is established.The process control method is used to support the project process.The control index data is statistically analyzed and processed.According to the obtained process control parameter CP value and the mean and extreme difference control charts,the status of each indicator is determined,and corresponding technical improvement measures and management ability improvement suggestions are proposed.Finally,the segmentation quantitative assessment method is used to evaluate the quality of the initial support section of the tunnel after the variation analysis and process control.Firstly,the health degree theory and the health function corresponding to it are put forward,and on this basis,an appropriate health function is established for each quality control index,so that the index can be quantified.Secondly,the unit will be divided according to the project selection paragraph,and Quality assessment is performed for each unit;finally,each unit assessment result is summarized and the final quality assessment results are derived based on the most unfavorable principle.