Risk Assessment Of Tiefengshan Tunnel In Preliminary Design Stage

Currently,China is in the phase of economic booming,especially the surge in resource liquidity,which brings rapid development to tunnel construction.The construction scale becomes huge and hydrogeological conditions tend to complicate.During the process of tunnel construction,tunnel traverses variety of adverse geology like fault fracture zone,swelling rock under high stress,which will cause serious threat to safety.At the same time,tunnel is a kind of semi-enclosed structure,the pollutedair in tunnel can’t be eliminated timely especially for the extra-long tunnel,which could cause serious consequence in case of fire.Therefore,it is necessary to take fullconsiderationof possible risk during in construction and operation in the period of tunnel design,risk materialization helps to make avoidance measures for each type of risk,which ensures the safety of tunnel design,construction and operation phases.On the basis of in Tiefeng Mountain tunnel,and itspossible risk in design,construction and operation,this paper carries out research about risk assessment in the preliminary design phase by information-gathering,project research,theoretical analysis、numerical simulation and so on.Main research contents are as follows:(1)Combine the project of Tiefeng Mountain tunnel,and put forward to risk assessment process and methods applying for design phrase of extra-long tunnel.(2)According to the results of expert investigation method,identify and sort the risk factors of each risk event,then determine major risk sources including collapse,inrush water,structure design,operation and fire.(3)According to the comprehensive risk rating of main risk events of Tiefeng Mountain tunnel evaluation,and other related information,this paper puts forward to elaborate and avoidable measures.It take analysis software to calculate and evaluate the security of tunnel lining structures under conditions of Ⅳ-class and watery surrounding rock and emergency parking strip in Ⅳ-class surrounding rock.This paper gives ventilation scheme for the Tiefeng Mountain tunnel according to natural ventilation and long highway tunnel ventilation,evaluate the risk of ventilation and fire,and formulate tunnel fire emergency plan to ensure the security during the period of design,construction,and operation.