Research On The Evolution Of Structural Cracks And Damage Of Urban Underground Comprehensive Pipe Gallery And The Mechanism Of Repair And Plugging

The urban underground comprehensive pipe gallery has entered the period of rapid development in China.However,due to the initial defects of construction or the adverse load during operation,the main structure of the underground comprehensive pipe gallery is prone to crack and water leakage.As an underground structure,the cracking of the main structure of the integrated underground comprehensive pipe gallery will lead to groundwater leakage and even influx into the underground comprehensive pipe gallery,threatening its structural safety and long-term durability,and even causing inestimable economic losses.In this thesis,therefore,the main structure of urban underground pipe crack damage disease problem,on the basis of the practical investigation,based on the in-situ test and finite element numerical simulation of the research reveals the pipe rack main structure evolution mechanism and the stress distribution law of crack damage diseases using high-performance plugging material in the underground comprehensive pipe gallery structure crack repair bond test and field crack leak test,It can provide some theoretical guidance for the prevention and control of underground comprehensive pipe gallery damage.The main work includes the following three aspects:1.Selected a typical underground pipe gallery project as the research object,has carried out the underground comprehensive pipe gallery structure health status detection,the main pipe rack along the crack damage disease detection,concrete rebound strength test and test of concrete carbonation depth in detail on the crack distribution location,length,width,Angle and quantity was analyzed,and on this basis,the comprehensive pipe gallery side wall into the causes of cracking analysis of body structure.2.On the basis of the analysis results of on-site inspection data,the common vertical cracking disease of the side wall of pipe gallery is selected as the research object,and the influences of design parameters of pipe gallery,pouring construction process and hardening and shrinkage characteristics of concrete itself are comprehensively considered.The numerical simulation research of vertical cracking disease evolution of pipe gallery structure is carried out by using ABAQUS finite element software,and a series of comparative working conditions are designed.This paper mainly considers the influencing factors of concrete strength grade,reinforcement ratio,concrete linear expansion coefficient,continuous pouring length,first pouring height and so on,reveals the vertical crack evolution and stress distribution law of pipe gallery side wall under different working conditions,and gives some corresponding engineering suggestions and measures.3.In the aspect of crack repair and treatment of the main structure of the comprehensive pipe gallery corridor,a kind of high performance plugging material and its corresponding mechanical properties are introduced.The bonding tests of the comprehensive pipe gallery corridor structure are carried out and the bonding properties of the material under different bonding conditions are analyzed.In practical underground comprehensive pipe gallery engineering,typical cracks are selected and plugging tests are carried out on underground pipe gallery structure cracks by using high-performance plugging materials.