Stability Control Of Surrounding Rock Research Articles

Investigations of Support Failure and Combined Support for Soft and Fractured Coal-Rock Tunnel in Tectonic Belt

The structural integrity of coal and rock tunnel affected by structural belts is generally poor, and the fracture development leads to the failure of support. Therefore, in this study, the tunnel deformation characteristics and deformation control technology were conducted using a combination of field investigation, laboratory experiment, theoretical analysis, field test, and other methods based on the Mukong coal mine. First, field investigations show that the main structural support failure often starts from some key parts associated with weak strengths, and the deformation is basically unevenly distributed. For this, the structural plane of tunnel rock mass was investigated and the internal structural deformation of the surrounding rocks was also monitored through the peepholes. In addition, point-load strength test was also conducted. Field observations and testing results show that rock fissures in the tunnel are well developed and a large loose circle will be formed after excavation. According to Barton Classification Q value and rock mass rating value, the mining tunnel stability falls into the category of Class V, i.e., the surrounding rock is poor or extremely poor. Finally, the support principles concerning surrounding rock stability control technology were proposed. The core idea is using support reinforcement repeatedly for several times until both internal and external load-bearing capacities of the surrounding rock are met. For the support reinforcement, a test with combined support scheme was conducted, including short bolts, long anchor cables, and U-steel brackets. Monitoring results of site application show that the proposed scheme contributes to the long-term stability of tunnel surrounding rock.

Surrounding Rock Stability Control of Auxiliary Return Airway in High-Stress Working Face

Surrounding Rock Stability Control of Auxiliary Return Airway in High-Stress Working Face

Stability Analysis of Tunnel during the Excavation Based on ANSYS

This paper combines the geological condition of Miaoziwan tunnel and numerical simulation software ANSYS to analyze the displacement and stress condition of surrounding rock before and after the excavation. Furthermore, the stability of overlying rock in the tunnel was studied based on the displacement and stress condition of surrounding rock. The breaking law of overlying rock was studied considering the influencing factors to the stability of surrounding. The study and analysis to the breaking law of overlying rock can be helpful to the improvement of surrounding rock stability control and supporting system. Moreover, the result can be the guidance to the excavation.

The Integrated Control Countermeasures on Floor Heave of Broken Soft Rock with High Ground Stress

The floor heave is one of the key issues of surrounding rock stability control during the deep well mining process. To solve the problem about floor heave occupying the most of roof and floor convergence deformation, the author analyzed the engineering geological conditions of broken surrounding rock and the floor heave features in PanEr Coal Mine East 2 mining area when it through the fault zone with high pressure. It pointed out that we should make full use of the reinforcement of the roof and laneway's side to limit the deformation of the floor, and make use of overbreak, prestressed anchor cable, bottom corner bolt, deep hole grouting and backfill as direct bottom control countermeasures.

Three Dimensional Elastic-Plastic Numerical Simulation of Tunnel Excavation Sequence of Dalian Speed Railway

Dalian speed railway tunnel is located in complex soft rock and soil, the road foundation deform and surrounding rock stability control is a concern problem. Along with the unloading process of excavation, surrounding rock moving to inner hole, while exceeding the elastic limitation, the plastic deform and the surrounding rock destroy then occurred. The paper adopted three dimensional elastic-plastic method based on Mohr-Coulomb yielding criterion and carried out numerical simulation of excavation process, in order to analyze and compare the surrounding rock vertical displacement contour, ground surface settlement and damage zone corresponding to different construction sequence. The elastic-plastic numerical method can reflect the damage and destroy character of nonlinear soil material of surrounding rock corresponding to different construction scheme, the simulation result has active guiding meaning for the Dalian speed railway tunnel construction design and dynamic analysis.