Analysis Of Tunnel Dynamic Characteristics With Defects In Construction Quality

In recent years,with the rapid development of highway and high-speed railway in our country,the number and mileage of railway tunnel and highway tunnel are increasing rapidly,China has become the world’s largest construction and construction speed of the tunnel.However,due to the tunnel construction process geological exploration is unknown,management is not in place,construction is not standardized to create or under construction of the tunnel there are quality defects.These defects lead to the tunnel lining cracking,spalling,water leakage,the weight of the tunnel lining damage and even collapse.At the same time,China is an earthquake-prone country,and the damage to the underground structure caused by the earthquake is increasing.Among them,the tunnel with quality defects is more likely to be destroyed,and the damage caused by tunnel damage is immeasurable.In this paper,the dynamic analysis of several quality defects caused by the tunnel construction process is carried out to study the dynamic characteristics of the tunnel when the quality defects exist in the tunnel,and the reinforcement measures are put forward for these quality defects.According to the above ideas to carry out the following aspects of work:(1)Summarizes the main causes and hazards of the quality defects of tunnel support structures,analyzes the common quality defects and its impact on the long-term operational safety of the tunnel support structure.(2)The finite element model of defects such as voiding,insufficient strength and insufficient thickness in the initial support is established.The transient analysis of ansys is used to analyze the acceleration response and the maximum principal stress response under the defects of various defects.Summarize the Dynamic Response of Tunnels under the Condition of Quality Defects.(3)Using the maximum principal stress peak of each quality defect,the influence degree of each quality defect parameter on the maximum principal stress is analyzed,and the sensitivity factor of each quality defect parameter is obtained,and the most sensitive quality defect parameters are obtained.(4)According to the results of the sensitivity analysis,the reinforcement method is proposed for the most sensitive quality defects.In this paper,three treatment schemes are designed:grouting reinforcement,20cm lined reinforcement,grouting + lining reinforcement,numerical simulation analysis,comparison of three treatment options,so as to select the most appropriate treatment.