Safety Risk Assessment Of Adjacent Buildings In Metro Shield Construction

Based on large of domestic and foreign literature on shield construction,this paper referenced the risk management of Wuhan subway tunnel passing through existing structures in recent years,and analyzed the monitoring data in the project.On the basis of these results,the reasons for the risk were summarized at first,and then a safety risk assessment and management system for a subway shield construction through adjacent buildings were established.Therefore,the risk control technology for shield construction has been further optimized.At present,the research results have been applied to the project of Wuhan Metro Line No.7(between Hong Kong Road Station and Sanyang Road Station)crossing the surrounding buildings,and the results show that the safety and economic effects of the project have been significantly improved.As an important means to prevent shield construction accidents,it is necessary to effectively strengthen the risk management of subway shield construction.In the early stage of shield construction,the main contents of subway shield construction risk management include safety risk assessment of adjacent buildings on the route,selection of appropriate shield technology and preventive measures,and the smooth construction of the shield construction on the basis of the safety of adjacent buildings.This paper starts with the common risk management steps and analyzes the safety of adjacent buildings during the construction of subway shields.The factors affecting the safety of adjacent buildings during the construction of subway shields were identified at first,and the the settlement process of the surrounding surface of buildings with different structures were analyzed,so risk identification were analyzed from two aspects of structure and risk management.Besides,this paper presents the risk assessment model based on monitoring data,including fuzzy pattern recognition model,multi-level fuzzy optimization model and fuzzy optimization model,and a fuzzy scale value method for the relative importance of adjacent indicators.Through the actual site survey report,survey record,construction monitoring report,as well as comprehensive consideration of the characteristics of engineering geology,risk factors of shield construction,the safety risk ranking model of the buildings around the shield tunneling interval were obtained to determine whether there are hidden dangers in the surrounding buildings.Finally,according to the evaluation model of surrounding buildings,the safety risk assessment of buildings with potential safety hazards was carried out.Moreover,this project follows the principle of "safety first,prevention and control combination".This paper established a risk assessment system for the surrounding buildings of shield tunneling based on the safety risk ranking model and safety risk assessment model.The results of the judging system have been applied to the early construction risk prediction of the 7th standard(Hong Kong Road Station to Sanyang Road Station Section)of Wuhan Metro Line 7,confirming the practicability and operability of the system.Under the premise of ensuring the safety and stability of surrounding buildings,the construction of subway shield can be carried out smoothly.