Rules Of Stress Release In Tunnel During Excavation And The Opportunity Of Support In Soft Rock

Through the contrast of several projects's convergence of surround rock in tunnel in recent several years, paper researched the transmutation of surround rock with the excavation pushed forward in different geology, and the influential factor to it, and then, based on the systemic numerical test, paper discussed the influence of the influential factor to the displacement of surround rock. Then, through the relationship of displacement release and excavation place from three-dimension numerical model, and the relationship of displacement release and stress release from two-dimension model, we can get the relationship of excavation place and stress release. At last, according to the standard of opportunity of support, this paper gets the opportunity of support for different kind of rock in space. The main result:According to the contrast and analysis of the data from measure, make sure the influential factors to the convergence of surround rock.For the different factor, paper makes a numerical analysis of effect to the displacement release, and received the different influence to it.According to the above analysis, paper makes sure three kinds of typical value, and gets the relationship of excavation place and stress release of them.Based on the physics meaning of opportunity of support, and the formula of plastic region and loosen region, as well as the displacement of surround rock, from the resolve method, paper give a standard in quantity of opportunity of support. And then, combined with the relationship of excavation place and stress release, paper gets the opportunity of support for different kind of rock in space.