Study On Risk Law Of Collapse Disaster In Mountain Road Tunnel Construction

As result of rapid economic development,the mileage of expressways is showing a trend of rapid increase.As an important infrastructure for highway construction,the tunnel has the characteristics of complex geological conditions and narrow construction environment.Rock mass collapse is one of the most common risk events during tunnel construction.Collapse will not only lead to casualties and huge property losses,but also delay the construction period and delay the construction progress.To prevent any possible collapse,it's necessary for us to conduct a research on control of the collapse risks,correctly understand the law of evolution behind the collapse risks,and take reasonable countermeasures.Therefore,studying the mechanism behind the formation of collapse risks in tunnel engineering,as well as the triggering factors is of great significance.In order to study the formation mechanism of collapse risk,Firstly,based on the theory of accidental release of energy,the paper analyzes the internal mechanism and law underlying collapse risks in tunnel engineering.Secondly,the paper uses the limit analysis method and strength criteria to establish a destabilized energy function for unstable rocks which are liable to collapse in the tunnel.Thirdly,after studying the law behind the formation of collapse risks,the paper puts forward the idea of safety coefficients,and uses it to analyze the factors which may trigger a collapse risk under engineering conditions.Finally,based on the risk energy control theory,the paper puts forward a host of countermeasures,attempting to reduce the collapse risks in tunnel engineering at the maximum.Contents of the paper divide into the following:(1)By firstly sorting out and summarizing the theories on rock collapse in tunnel engineering,and secondly by referencing the existing research theories and contents,the paper,from the perspective of energy release theory,studies and analyzes the collapse risks in tunnel engineering.The paper mainly touches on the research on internal energy mechanism behind the formation of collapse risks,analysis of the rock deformation and destabilization process,as well as the energy evolution law behind the collapse risks in tunnel engineering.(2)By integrating the research on the formation of collapse risks with the ultimate balance theory of rock & soil mechanics,as well as the rock mass strength yield criterion,the paper establishes a destabilized energy function for rock collapse in tunnel engineering,analyzes the critical state of the collapse risk,and studies the approach of attributing values to the parameters for the equation of state.(3)After studying the methods of deciding the adverse factors from the collapse risk in tunnel engineering,the paper puts forward the idea of safety coefficients,and before making a definite conclusion,the paper conducts a quantitative analysis of the safety of rock mass in the tunnel from the two aspects of ultimate equilibrium and upper limit of energy.The paper also studies the factors which may be liable to trigger a rock collapse in tunnel engineering.(4)From the perspective of energy control,the paper systematically studies the mechanism for preventing and controlling collapse risks in tunnel engineering.The paper analyzes the capacity of the rock system in preventing and controlling any possible collapse.And finally,based on the results from research on the energy control mechanism,the paper specifically puts forward a host of measures for preventing and controlling collapse risks in tunnel engineering.