Study On Mechanical Characteristics Of Deep Tunnel With High Stress And Measures For Rock Burst Prevention

With the rapid development of underground space,The excavation of deep tunnel under high ground stress continues to increase,Damage caused by high ground stress,rockburst and other engineering accidents to the construction workers and operating equipment,property security situation has brought a huge threat.Although the country has done a lot of research on the construction of high stress and deep burial tunnel,it has also put forward some special technology of supporting design and construction,but few results can be applied to practical engineering.In assessing the stability and safety of high-lying deep-buried tunnels,it is necessary to clarify the mechanical properties of the surrounding rock and supporting structures during the construction process,which brings important safety and security to the initial design and construction of the tunnel.In this paper,the stability of the project in the process of deep ground stress tunneling is systematically studied by field test,monitoring and theoretical analysis of the diversion tunnel project of Neelum-Jhelum Hydropower Project in Pakistan.The main work is as follows:(1)According to the geological situation of the diversion tunnel of the Neelum-Jhelum hydropower project and the tunnel excavation plan,the corresponding tunnel construction monitoring plan is worked out and the test results of the stress state and deformation of the surrounding rock during the tunneling process are analyzed.(2)The three-dimensional elasto-plastic finite element model of Neelum-Jhelum diversion tunnel is established by numerical calculation method,and the whole process of tunnel excavation and support under high ground stress is simulated.The stress,deformation and mechanical properties of surrounding rock during tunneling are analyzed.(3)Through the monitoring of the microseism of the surrounding rock,the possibility of rockburst in the surrounding rock is analyzed,and the countermeasures of rockburst prevention and control are discussed.