| Since the beginning of the 21 st century,with the development of economic globalization,the contradiction between population,resources and environment has intensified,furthermore,problems in urban planning,transportation construction,and environmental protection have become increasingly prominent.In this case,people have gradually focused on the construction of underground projects.The subway tunnel,as the main form of underground engineering development,greatly relieves the pressure of urban traffic tension.However,the construction of subway tunnels in our country is not completely synchronized with the corresponding research on guaranteeing construction safety at present,indicating that fast and non-interference real-time monitoring technology is required to ensure the safety during the construction of subway tunnels.As wireless sensing network(WSN)monitoring technology is widely used in structural monitoring in the field of civil engineering,which realizes the goal of real-time intelligent management of tunnel construction monitoring and solves the tunnel safety monitoring problem.In this context,this paper adopts statistical analysis,theoretical research,numerical simulation,BIM technology and field verification to carry out a series of research work about the realization of subway construction safety risk perception and visual management.The main research contents and results are as follows:(1)Collecting 176 cases of subway tunnel construction safety risk accidents through literature and web pages and summarizing the mechanism of subway tunnel construction risk by Combining with the accident cause theory.Based on the characteristics of subway tunnel construction risk perception,the "human-machineenvironment-structure" are sorted out,which lays the foundation for subsequent construction risk assessment.(2)Relying on the Shenzhen Rail Transit Line 13 tunnel excavation project,the wireless monitoring field application research was carried out,and the wireless sensor network monitoring system was adopted to carry out the wireless sensing practice of the tunnel structure.This system has the characteristics of wireless real-time monitoring,integration of multiple sensor data,small size and easy installation.This paper utilizes wireless laser ranging sensors and wireless inclination sensors to monitor the safety status of the tunnel structure,and find that the structure monitoring during the construction period needs to be strengthen to protect the original sensor through engineering project monitoring practices.The preliminary data processing analysis after the installation shows that the structure during the construction period will basically not undergo major deformation under the condition of timely support,implying that it is in a safe state.(3)Aiming at the Shenzhen tunnel in soft ground,the short-bench method excavation process was studied through numerical simulation,and the force and deformation of the tunnel excavation process were clarified.For areas with poor geological conditions,the backward advanced deep-hole grouting pre-reinforcement technology is used to form a relatively stable "grouting reinforcement circle" in the surrounding soil,effectively cutting off the surface water seepage path,reducing the development and expansion of soil cracks,and making the tunnel surrounding rock better exert its self-stabilization ability.At the same time,the tunnel excavation and support model is constructed based on BIM technology,and the tunnel construction is completely displayed in front of people through visualization technology.In addition,the construction of an intelligent sensing and control system for tunnel construction risks can give full unleash its ability to manage project site monitoring data.The system receives real-time monitoring data from site projects,and automatically analyzes and processes monitoring data and risk assessment in time to pre-alarm,based on which engineers are able to avoid risks in time.This also verifies the reliability of the risk intelligent management and control platform and the monitoring and early warning methods.(4)According to the realization of intelligent perception and visual management of tunnel construction risks,32 monitoring information source indicators are further determined,and an FME-DS evidence multi-source data fusion model framework is constructed to realize the integration of different dimensions,qualitative and quantitative,and heterogeneous data.Through layer-by-layer information fusion to output the comprehensive evaluation results of tunnel safety,a comprehensive and comprehensive safety evaluation of tunnel excavation is realized. |
