Research On Lining Deformation And Ground Disturbance Of Shield Tunnel Construction Based On Wireless Monitoring Technology

In recent years,the development of rail transit has become an indispensable part of infrastructure construction.Among them,shield tunnels do not require additional land occupation,have little impact on ground transportation,and have high construction efficiency.strong adaptability and other characteristics,are widely used in urban subway construction.In the construction process of the subway project,construction monitoring is very important to the safety of the project.The traditional manual monitoring method,due to factors such as insufficient manpower,cannot achieve detailed and accurate monitoring of the construction environment,and cannot timely discover possible hidden dangers,in which the security risk of the project is greatly improved.the wireless sensor network(Wireless Sensing Network,WSN)technology has the advantages of simple operation,convenient deployment,intelligence and high degree of automation.It can realize automatic,real-time and long-distance barrier-free security early warning,quickly obtain the status data of the monitoring structure,and improve the safety of the construction period.This paper relies on the second phase(northern extension)project of Shenzhen Urban Rail Transit Line 13,studying the optimal section installation position of wireless sensors in shield tunnels,establishing and optimizing the layout of wireless sensor networks in tunnels are the main goal;the means used include but are not limited to laboratory tests,field tests,numerical simulations,etc.The main research contents are as follows:(1)Through field tests,the limit transmission distance and stable transmission distance between wireless sensors in the tunnel are explored from the perspective of instrument accuracy.The energy consumption of sensor networking is explored through indoor experiments,and the results show that the energy consumption of wireless sensors is the same as that of the sampling frequency is positively correlated,the faster the frequency,the more energy consumption.Finally,for the wireless sensor network in the form of mesh topology and linear layout,two different networking capabilities of the same cross-section linear shape and different crosssectional linear shape consumption model are proposed.(2)Establish a finite element model based on actual engineering parameters,analyze the convergent deformation form of the non-vertically symmetrical lining ring in the shield tunnel,and further study the deformation degree and characteristics of each segment of the lining ring.The conversion formula between the inclination angle change of the inclination sensor and the horizontal convergence of the lining ring,and the relative error evolution method are used to deduce the optimal installation position of the inclination sensor on the installation section.(3)The application and research of wireless sensor network technology has been carried out based on actual projects.The results show that compared with manual monitoring,wireless monitoring has obvious advantages in capturing the deformation of lining structures in real time,and can not only better observe the deformation of lining structures situation,it can provide early warning for possible emergencies.At the same time,it can also timely monitor the deformation of concern in real time.(4)Combining with the north extension project of Shenzhen Metro Line 13,through the establishment of a three-dimensional finite element model,the deformation law of the lining and the surrounding soil during the construction of the shield is analyzed,and the influence range and related definitions of the monitoring section are proposed.Based on this,an optimization strategy for the layout of the shield tunnel wireless sensor network is proposed.