Research On Quality Control Of Shield Tunnel Assembly

With the rapid development of rail transit,subways,intercity rails,etc.have rapidly emerged in major and medium-sized cities in my country.Shield construction is currently the most important construction method for rail transit projects.The development of its related construction codes,acceptance codes,industry standards,and quality control methods has not kept pace with the development speed of rail transit,and quality problems have become increasingly prominent.Therefore,starting with the quality of shield construction,in-depth research is imperative.Previous studies have shown that the quality of shield construction is mainly reflected in the quality of shield tunnel assembly,which is specifically manifested in the staggering of the segments,water seepage,and damage.This article first learns relevant domestic and foreign literature,industry norms,and quality management theories and methods to find out the potential factors that affect the above-mentioned assembly quality;on this basis,a Guangzhou intercity rail project is used as the research object,and the Logistic regression model is used to Perform regression analysis on the influencing factors of assembly quality,explore the relationship between each influencing factor and assembly quality,and find out the important factors affecting assembly quality.Finally,aiming at these important influencing factors,based on the idea of total quality management,combined with PDCA,fishbone diagram and other quality management tools for improvement.The study found that: 1.The construction method is the most important factor affecting the quality of the shield tunnel assembly.In the construction method,the deviation of the tunnel axis,the thrust of the shield machine,the amount of excavation and the grouting are the most important factors.Therefore,during the tunneling process Controlling these factors is the key to ensuring the quality of the shield tunnel assembly;2.Through the technical training,increasing the monitoring frequency,controlling the tunneling parameters and other management and control methods can effectively reduce the assembly quality problems.In addition,in this study,by comparing the difference in the assembling quality of shield tunnels in different value ranges of influencing factors,the scope of some shield parameters such as thrust and grouting of the shield machine was basically determined.The results and experience can provide a reference for shield construction in the region,and provide a basis for improving the construction specifications,acceptance specifications,industry standards,and quality control methods of shield construction.