Study On Safety Risk Management And Control System Of Loess Tunnel Construction

System vulnerability evaluation,knowledge management theory,etc.are used to study safety risk management and control system of loess tunnel construction.The elements and disturbance factors of the safety management system of loess tunnel construction are analyzed,and the evolution trend of construction safety management system is put forward.After analyzing the coupling relationship between the vulnerability factors of loess tunnel construction safety management system,the vulnerability evaluation model of safety management system based on catastrophe theory is established.Then,the basic framework of tunnel construction safety risk management and control system based on "four modernizations" is designed.The framework is studied from three aspects: improvement of safety management system based on vulnerability evaluation,classification,and identification and sharing of safety risk management information,informatization of tunnel construction safety risk management and control based on modern information technology.Then,the optimization process of safety risk management and control based on "PDSA-SDCA cycle",optimization process of tunnel construction safety management system based on vulnerability evaluation,knowledge funnel transformation model based on SECI and informatization framework of tunnel construction safety management based on Internet of things perception are proposed.Finally,an example of loess tunnel engineering is used to analyze vulnerability of safety management system and safety risk management and control strategy.(1)Analysis of disturbance and evolution trend of safety management system of loess tunnel constructionThe geological condition of loess is special.The vertical joint,structure,collapsibility and water sensitivity of loess will cause great potential risks to tunnel construction.Among them,collapse is the main potential risk.Safety management system is an important means to resist all kinds of potential risks.In this paper,the safety management system of tunnel construction is divided into six parts,which are project coordination,safety organization,behavior control,site and facilities,safety technology and emergency management.When the safety management system is disturbed,the disruptive of potential risks will gradually appear.The internal and external disturbance factors of the safety management system of loess tunnel construction are analyzed.On this basis,the evolution trend of safety management system is analyzed.Firstly,data of construction accidents are analyzed.The positive effect of the current safety management system and the trend of diminishing marginal effect of safety management system effectiveness are defined by using the judgment criterion in the control chart method.The management efficiency of safety management system will be a regular curve with the advance of time and the development of technology.The change of safety management efficiency curve is continuous,similar and repeated.In the current situation,perfection of safety management system and upgrade of safety management based on modern information technology are two important driving forces to improve the safety management effectiveness.(2)Study on vulnerability evaluation of loess tunnel construction safety management systemThe vulnerability of tunnel construction safety management system consists of 3 characteristics: exposure,sensitivity and adaptability.Based on the logical relationship of AHV(Airlie-House-Vulnerability)model framework,the vulnerability evolution analysis model of tunnel construction safety management system is put forward under the influence of disturbance factors.The three elements of vulnerability appear successively under the influence of disturbances.The state of each element exhibits discontinuous changes.The mutation occurs when the element reaches the critical state,and the process of the element fails.The probability of accident induced by safety risk is greatly increased.After analyzing the vulnerability factors of the six components of tunnel construction safety management system,27 key factors of tunnel construction safety management vulnerability are obtained.The interpretative structural modeling method(ISM)is used to establish the list of vulnerability relation tables.Strongly connected loops are discovered.Reach ability matrix is solved.And then,interpretation structural model for vulnerability factor of tunnel construction safety management is obtained.Analysis of the model shows that,there is a strong connection between the rationality of the construction scheme,the safety personnel,the professional skills of the personnel,the investigation of the safety awareness and the level of safety culture.These elements interact with each other to form a subsystem.Safety system plays a key role in system vulnerability.Based on the multi-criteria evaluation method of catastrophe theory,the vulnerability factors of tunnel construction safety management system is classified,and a multi-level evaluation model is established.The model consists of three evaluation levels: X-Y,Y-Z,and Z-W.Then,the evaluation process and evaluation formula of factors at all levels are put forward.The vulnerability index system of tunnel construction safety management system is also given.(3)Optimization design of safety risk management and control system of loess tunnel constructionSafety risk management and control is an important part of safety management.There are loopholes and weak points in the current safety risk management and control system.This makes the safety management only inefficient reinforcement of the existing safety management system.The goal of tunnel construction safety risk management and control system optimization is determined to recognize the efficiency evolution curve of safety management system.In the optimization system,on the basis of systematic optimization based on vulnerability evaluation,modern information technology means should be used to realize "four modernizations",that is,safety management system evolution,safety risk management and control process optimization,safety risk knowledge transformation,safety risk management and control information.Meanwhile seven optimization principles of tunnel construction safety risk management and control system are put forward.Safety risk management and control system of tunnel construction is constructed.This system architecture makes the evolution of safety management system,safety risk knowledge transformation,safety risk management information and safety risk control process optimization as important supports for efficient operation of safety risk control system.It combines the current mature rules and methods of management and control,and continuous improvement and standardized management and control are carried out.In the aspects of safety risk management and process optimization,a process improvement and standardization synergy model based on "PDSA-SDCA cycle" is established to enhance safety risk management and control efficiency.In the aspects of evolution of safety management system,it focuses on the process optimization and improvement strategy design of safety management system based on vulnerability evaluation.In the aspects of knowledge transformation of safety risk,safety management and control information is refined and classified,and the control information acquisition obstacles and acquisition methods are proposed.A knowledge funnel transformation model based on SECI model is established to strengthen engineering knowledge learning and transformation,and further to service each link of project management.Then,five modes of safety risk information sharing are put forward.In the aspects of safety risk management and control informatization,the achievements of modern information technology should be fully used,and the application of new technologies represented by Internet of things perception should be enhanced.(4)Study on safety risk management informatization of loess tunnel constructionBased on the analysis of the latest policy direction of safety management,there are still some obstacles in the realization of the goal of safety planning.These obstacles include stylized safety management engineering,fragmented safety management information,and declining effectiveness of safety management system.At the same time,this dissertation points out the current technology and application of tunnel safety risk management information technology.It is pointed out that the current tunnel construction safety management information technology has some problems,such as homogenization of technology,implementation of visualization,lack of standard management,lack of overall planning,difficult cost measurement,and inefficient evaluation.Then the trend and core technology of tunnel construction safety management informatization are analyzed.The information framework of tunnel construction safety management based on the Internet of things perception is constructed.In the framework,perception technology and communication technology are taken as the source data acquisition and transmission technology.Safety control information interaction platform is taken as the interface.Knowledge base based on SECI knowledge funnel transformation model is taken as the data pool.The framework realizes information perception,interaction,sharing and application.It can provide real-time updates and reliable data management information for enterprise headquarters,project departments and other safety related personnel.At the same time,"four modernizations" support of the safety risk management and control system framework is used to improve safety risk management information process of tunnel construction,and efficient hidden danger identification and scientific risk evaluation process are carried out.(5)Case study on safety risk control of loess tunnel constructionSafety management of the tunnel construction project of LV Lin special railway in Shanxi is investigated and studied.Safety management documents of the general contractor and subcontractors are collected,and personnel interview is conducted.This project has typical characteristics studied in this dissertation.The safety documents are complete,but the identification efficiency of safety risks is low.Safety warning and emergency mechanism is not perfect.The special emergency plans for major hazard installations are lacking.The supervision of the prone areas of safety accidents is discontinuous.The knowledge of construction in loess area is not unified.Therefore,safety risk management of this project has greater control errors and blind spots,and the efficiency of safety management is low.Two safety production accidents during the rainy season of 2016 are taken as examples.It is found that the project did not collect and analyze the key rainfall conditions affecting the construction of loess area.The harm of long and large rainfall is ignored,and the tunnel construction technology has not been adjusted in time.The project lacks coordination and communication in the emergency response after the accident.After the accident,the multi organizational conflict appears rapidly,and the adaptability of the whole project safety management system is reduced.After analyzing the vulnerability of the system,it is believed that the technical scheme of the project conforms to the characteristics of the loess tunnel construction,but there are many problems in safety risk management.The core problem is the vulnerability of tunnel construction safety management system.Hazard identification efficiency and processing capacity are low.So that technical solutions cannot be timely response to changes due to personnel,machinery,materials,environment and management.This increases the probability of safety risks.Finally,suggestions for construction safety risk control strategy of LV Lin special line tunnel are put forward.They include the ability to improve safety risk identification based on vulnerability analysis,the improvement of abilities to manage and control safety risks based on hazard management,the promotion of information sharing of safety risk oriented knowledge management,etc.The general contractor of the project uses the vulnerability analysis method to conduct emergency coordination,information sharing,dynamic pace adjustment and other initiatives.Through these methods,the sensitivity of the safety management system has been reduced,and the adaptability of the system has been improved.In the following winter construction and other links,the construction safety has been guaranteed.