The Numerical Simulation Of Pressure-relief Blasting In High Geo-stress Tunnel

With the rapid development of transport, a lot of depth big, big traffic tunnel length the need to build, and highland stress can lead to such tunnels and other underground engineering surrounding rock instability problems. In the role of large-scale excavation, loss of deep tunnel surrounding rock stress occurs at the Highlands strong unloading rock burst caused by other disasters, causing casualties, schedule delays and so on. In this paper, the Institute predecessors have, from the history of relieving shot technology research, numerical simulation of blast-related departure, summed up the existing deficiencies, for stress relieving shot technology high ground tunnel, numerical simulation.Paper outlines the rock breaking mechanism in blasting, discusses the constitutive model of rock blasting theory, the study of rock constitutive equation models at different stages of the theory, analyzed the rock under the charge structure and the role of different ways in different detonating device rock crushing process, is behind the pressure relief blasting relief programs provide a theoretical basis. The display kinetic theory of knowledge, it is to select the appropriate finite element software for blast simulation. Considering rock mechanics, blasting dynamics and finite element numerical calculation method, the display dynamics finite element analysis software Ansys / Ls-Dyna selected in line with article Numerical simulation of parameters, including basic equations, finite element discretization, time control, model boundary conditions and other parameters of the basic conditions, in addition, the need to select the appropriate model of rock material model, explosives and other materials, and the model for numerical simulation of the methods described herein. Combination of the above theoretical basis, the simulation of the charging structure has 4 representative structure: continuous charging structure, the radial decoupling charge structure, the axial hole top coupling charging structure and not the end of the axial hole coupling charging structure, in addition to the analog device structure of the drug, but also to simulate the detonation of explosives in two ways: forward direction and detonate detonation.Through different charge structure and the way of initiation blasting process different simulations, analyze its structure blasting, the blasting process selected on minimal disturbance of surrounding rock structure and charge initiation. Use Ansys static structural analysis module, the effect of relief after blasting simulation analysis. Static Numerical simulation of studies show that, compared with the previous relief after blasting vertical stress relief tunnel surrounding rock suffered stress displacement, horizontal, and surrounding rock have reduced to some extent. Description relief blasting on the tunnel wall rock stress transfer achieved a certain effect, relief blasting technology in highland stress tunnel operable, to a certain extent, to ensure the security and stability of the surrounding rock to prevent rock burst engineering and other disasters occur.Results of this research to the theoretical research and development is relatively slow, and generally applied relief blasting small section of the tunnel has a certain reference value and engineering significance.