Deformation And Disaster Analysis Of Shield Tunnel With Comprehensive Corridor

With the rapid development of China's economy and the continuous expansion of urban scale,urban surface space resources are seriously scarce.As a kind of underground space utilization,urban underground comprehensive pipe gallery has been recognized by all countries in the world.The construction of underground pipe gallery in the city cannot avoid the inevitable deformation of the soil caused by excavation,and excessive deformation will lead to serious damage to surface buildings,underground pipelines and other facilities.Based on the project of shenyang underground composite pipe gallery,this paper studies the surface subsidence law and soil deformation prediction caused by shield tunneling and the characteristics of adding solid at the cracked end.The main contents of this paper include:(1)The geological characteristics of shenyang city were analyzed,typical monitoring sections were selected,and the transverse surface subsidence of each section during the shield tunnel excavation was predicted by combining the project profile and construction parameters.The longitudinal surface subsidence characteristics were analyzed according to the field measured data.(2)Use the least square method to fit out the Peck formula suitable for this region,and get the Peck formula can well predict the lateral surface settlement in this region,and preliminarily calculate the width coefficient of the surface settlement tank and the value range of the maximum surface settlement,which can provide some reference for the future construction in this region.(3)In combination with the field engineering practice,the static loading test and the dynamic loading test of simulated tunnel shield shaft with cracked end and solid were conducted.The influence of loading mode,material ratio and initial crack on solid strength was analyzed.Among the three material proportions,the maximum peak strength of the specimen was found when cement slurry: sand =1:1.The more the number of cracks,the more the strength of specimen decreased.When the crack Angle is within a certain range,the strength of the specimen decreases obviously.(4)Analyzes the tunnel accident cases on site,records the process,causes and treatment of the accident,and summarizes the five main factors leading to the tunnel accident.