Papers by Keyword: Tunnel Surrounding Rock

Abstract: On the background of Jiangxi Wuning–Ji'an highway tunnel, the rock triaxial rheological testing machine is adopted to conduct hierarchical incremental cyclic loading and unloading rheological tests on class II, class III, and class IV rock on the tunnel site. Take class II and class IV surrounding rock for example, this paper analyzes the creep deformation rules over time in depth, studies rock rheological properties, and provides the best rheological model of tested rock. According to research findings, deformation of class II and class IV surrounding rock is composed of instantaneous elastic deformation and creep deformation. The instantaneous elastic strain value increases with the increasing stress level and the rock deformation manifests as brittle failure. The generalized Kelvin model is the best rheological model that describes deformation of class II and class IV surrounding rock.

Abstract: The point load test and rebound tests were part of a simple rock testing methods, which together with a user-friendly, work environment characterized by less demanding test, so test the application of rock in the tunnel are very broad. Obtained by these two tests of rock uniaxial compressive strength Rc saturation level for the characterization of rock hard quantitative indicators, in the rock classification has a high status. With the computer technology in tunnel works in the field of application that can batch test data to establish the tunnel surrounding rock classification system. Article is based on two kinds of test in the same tunnel project in contrast to the use, through the rock classification system to analyze and evaluate both.

Abstract: Freeze-thaw disaster is an outstanding problem of geotechnical engineering in cold regions. The temperature field of tunnel surrounding rock in Qilian mountain Osaka hill was calculated according to the transient heat conduction differential equation, meanwhile the freezing conditions of tunnel surrounding rock was forecasted and analyzed after its opening. The study shows that the freeze-thaw environment has a great influence on the temperature distribution of surrounding rock. The tunnel wall and near the mouth of the cave area are more susceptible to the influence of the open ground temperature and air convection, thus the temperature changes violently , but the temperature distribution in surrounding rock tends to be dynamic stable equilibrium as time goes on. The research results can provide a reference for tunnel design and construction in cold regions.

Abstract: The stability of tunnel surrounding rock is a key scientific issue in the design and construction of the tunnel engineering. Taking the load pattern of incremental form, the distribution law of stress and displacement field of the Osaka mountain tunnel after excavation was calculated based on the D-P yield criterion; Basing on the comprehensive heat and mass transfer theory, the temperature field in the surrounding rock was calculated and the variation of stress and displacement field after the surrounding rock experiencing the free-thaw cycles. All of the results can provide some references for the design and safe construction of the tunnel engineering under the action of freeze-thaw environment in cold regions.

Abstract: Tunnel engineering information construction has been widely used, and the back analysis is its core. As the common useful method, displacement back analysis is of special advantages. This paper introduces the calculative method based on the application in a railway tunnel. The result shows that strain softening model can be used to simulate the large deformation mechanism of surrounding rock.