The Research On The Time-reliability Of The Support Strcture And Risk Management Of Highway Mountain Tunnel

Due to the creep characteristics of the surrounding rock,the reliability and stability of the tunnel support system have significant aging characteristics.Many landslides occurred after tunnel excavation was completed for some time.However,there are few studies on the reliability of such accidents,that is,tunnel and supporting structures.At the same time,there is no systematic risk assessment system for tunnel engineering in China,which lacks effective management and evaluation for tunnel accident.In this paper,the RK75 + 880 section is studied with the background of Yuejiagou tunnel project,and the landslide occurred after a certain period of time.With the aid of finite element analysis software ABAQUS,considering the creep characteristics of tunnel surrounding rock,the aging reliability of tunnel support system and the risk management of tunnel engineering based on aging reliability are studied.The main contents are as follows:(1)The creep behavior of the surrounding rock and the interaction between the surrounding rock and the supporting structure during the creep process are analyzed,and the creep deformation forms of the decay and non-decay creep are introduced.Because the displacement of the hole is the objective and direct external manifestation of the mechanical properties and the steady state of the surrounding rock and the supporting structure under the influence of various factors,this paper focuses on the displacement To study the aging reliability of the tunnel support system.The time of failure of the support system is defined from the perspective of displacement,and the calculation method of ultimate displacement is introduced.(2)The RK75 + 880 section of the right frame of Yuejiagou tunnel was selected and analyzed by ABAQUS software.In the section,we choose the observation points of the vault,the arch,the arch and the arch and the arch,and analyze the stress change of the support structure at each observation point and the deformation of the support structure with time.Finally,According to the displacement time history curve of the support system,the aging failure probability of each observation point is calculated to analyze the aging reliability and stability of the section.(3)In the research of risk management of tunnel engineering,this paper makes a risk assessment of Yuejiagou tunnel by risk matrix method on the basis of the study of aging reliability.The risk matrix method also considers the probability of risk occurrence and the possible loss.The addition of the time-of-war risk makes the risk matrix method become a dynamic risk assessment method,which can take full account of the risks at all times during the tunnel construction process.Construction and reduce the construction risk is of great significance.