Study On Road Tunnel Operation Safety Assessment Methods Based On Risk Sources Analysis

With the rapid development of China's economy,more and more road tunnels are built.Long tunnels,cross-ocean tunnel,cross-river tunnel and other large tunnel projects are still growing.Underground interchange,spiral tunnel and other complex tunnel forms began to appear.While bringing convenience to the transportation,it also leads to the safety risk of the tunnel operation period.In recent years,fatal accidents which due to the characteristics of the tunnel's closure,small clearanceand others are serious and not easy to escape and rescue,and happen in domestic and foreign road tunnel sometimes.Great potential safety hazard was caused by the aging of tunnel structure,backward and lack of tunnel operating equipment.Increasing traffic volume leads to the increasing risk of tunnel operation.At present,our country pays more attention to the prevention and control work of safety risk to road tunnels,and has carried out the preliminary research.But there is still a long way to go to meet the demand for risk prevention and control of tunnel operation.In this paper,the research of operation accident toroad tunnel is carried out,and the risk source identification is carried out in detail.On this base,in view of the assessment of operation safety risk toroad tunnel,combined with the research of domestic and foreign operation accident of road tunnel,we will identify the risk source.The research on risk assessment of road tunnel operationdraw lessons from the risk assessment method of engineering construction,and put forward theassessment method to operation safety of road tunnel based on typical scene.However,this method is lack of clear direction and is only suitable for the safety assessment of road tunnel operation at the engineering feasibility study stage.Therefore,based in the identification of risk sources and the evaluation method of tunnel safety proposed by EuroTAP plan,grade evaluation method of road tunnel operation safety which has clear direction and pertinence is suitable for operation stage.With this method,the safety grade evaluation and management system of road tunnel operation is established.The main research results and innovations are as follows:1)Through statistics,investigation and analysis to accident case at operation period,we study the mechanism and logic of the accident and analysis the risk factor.Close to the relevant specification,we screen and confirm the source of risk from four aspects of operation management,mechanical and electrical facilities,civil structures,traffic environments.At the same time,we list the detailed inventory of risk sources,and screen out the key risk sources.2)Theconcept that risk probability is composed by probability and conditional probability of occurrence of risk was put forward.The risk loss model which unifies all kinds of losses into currency calculationis introduced intothe currency value conversion function and takes the value of time loss into consideration.According to the evaluation method of foreign countries and the actual situation of our country,social risk of road tunnel which acceptthe criterion of F-N curve was confirmed.And asimplified method which is more practical to the risk assessment and multi program risk level of the project at feasibility study stage was put forwardto evaluating the overall risk level of tunnel.This method is aimed to pro-vide a scientific and reasonable reference for safety risk assessment of road tunnel operation.3)Based on the identification of risk sources and tunnel safety evaluation methodproposed at EuroTAP plan and combined with related code of our country,8 kinds of security parameters evaluation score table include tunnel total parameters,power supply,traffic and traffic control,communications were reconstructed,a total of 177 sub items.This method which is combined with the actual situation of China's road tunnel expand the kinds of operational risk parameters:whole tunnel(plane line type,horizontal and vertical combination line,sight distance,tunnel length,lane width,number of tunnel holes),tunnel pavement,vehicle speed,and establish a set of suitable for road tunnel operation safety evaluation method which is appropriate with China's national conditions.4)In order to make the safety evaluation method toroad tunnel more applicable,the security and risk parameter evaluation is integrated into the database through VB and SQL server 2000 in this paper,and the evaluation model of safety operation level was implanted.Combined with the engineering project management,a suit of"safety grade evaluation and management system of road tunnel operation" was developed.This paper aims to simplify the evaluation method of road tunnel operation safety level to the application level,and reduce the professional requirements of the assessment personnel.The study of this paper which provide technical support for road tunnel operation risk assessment in the stage of feasibility study and operation aims to help people who in charge of the road tunnel figure out the sources of risk from the road tunnel road tunnel operation safety management work.And this method which provides the basis of risk decision for tunnel Manager has great significance in improving and promoting the development of road tunnel operation safety risk assessment technology.Because the operating risk source of tunnel system is very complex and extensive,the risk source identification in this paper can't be very comprehensive,but also need to be further improved.The safety and risk parameters of operational safety assessment and the corresponding scoresneed to establish scientific and complete data model which make road tunnel operation safety risk assessment technologyto further improve.