Mechanism and preventive measures of slurry leakage at shield tail brushes under abnormal shutdown condition—A case study

作     者：Fei Ye Haolan Feng Xingbo Han Xiaoming Liang Haidong Sun Wenjun Zhang Xiaoyong Cao 

作者机构：School of HighwayChang’an UniversityXi’an 710064China CCCC First Highway Consultants Co.LtdChina710065 Xi’anChina School of Civil EngineeringTianjin UniversityTianjin 300350China 

出 版 物：《Underground Space》 (地下空间（英文）)

年 卷 期：2023年第8卷第1期

页      面：144-161页

核心收录：

学科分类：081406[工学-桥梁与隧道工程] 08[工学] 0814[工学-土木工程] 082301[工学-道路与铁道工程] 0823[工学-交通运输工程] 

基　　金：conducted with funding provided by the National Natural Science Foundation of China(Grant Nos.51878060 52108360) 

主　　题：Shield tunnel Shield tail brushes Slurry leakage Jack retraction Segment displacement 

摘      要：Based on an underwater shield tunnel project,this study introduces the phenomenon of abnormal shutdown and the measures designed to mitigate problems in *** the strength of the analysis of the slurry leakage causes during re-tunneling,the mech-anism of slurry leakage induced by jack retraction was studied,and treatment measures of leakage at shield tail brushes were elaborated *** results show that the sudden change of stratum leads to an abnormal shutdown,and a sharp increase in the slurry pressure at the shield cut location leads to the slurry penetrating the gap between the outer wall of the shield shell and the soil,increasing the risk of instantaneous breakdown at shield tail *** radial displacement of the outer wall of the segments caused by retractions of three jacks and a single jack along the circumferential direction distinctly shows three regions and four regions,*** radial shrink-age of the outer wall of the segments at the jack retraction position decreases the tightness between the shield tail brushes and the outer wall of the *** expansion of the outer wall of the segments at the surrounding position,especially at the lower position,increases the slurry level to the radial shrinkage position of the segments,which increases the risk of slurry ***,when the shield machine faces an abnormal shutdown,re-tunneling,and assembly of segments,the jack can be gradually retracted from top to *** slurry leakage degree can be observed when retracting,and the corresponding measures can be taken for timely *** to the leakage degree,it can be determined whether to replace the shield tail brushes to reduce the risk of large-scale leakage accidents.