Research On The Deformation And Support Of The Roadway Under The Deep Multi-field Coupling Environment

Deep mining has been long plagued by the situation of high stress, high porepressure, high temperature and mining disturbance. Its essence is that deep rockproperties are different from shallow rock properties in a long-term multi-fieldcoupling environment, methods and theories for solving shallow mining method areno longer valid. The key to solving this problem is to enhance the understanding ofthe rock mechanical properties in the deep environment and adopt other morecomplex nonlinear mechanics theory. By means of theoretical analysis and numericalsimulation, based on THM coupling, this paper study the deformation law of theroadway and distribution of stress and displacement, and on this basis propose aneffective support program to control the stability of the surrounding rock. The mainwork of this paper is as follows:(1) This paper analyzes the characteristics of the rock stress-strain relationshipand a variety of strength criteria, and deduces the rock stress-strain relationshipexpressions after the peak, based on different strength parameters (including linearform, parabolic form and hyperbolic form), different softening parameters (includingthe equivalent plastic strain and equivalent plastic shear strain) and different strengththeory (including D-P criteria and C-M criteria).(2) This paper describes the complexity of stress field, the characteristics of thedeep rock self-destruction and other unique mechanical phenomenon such as zonaldisintegration, brittle-ductile transition. Then numerical model is established byFLAC3D software under the conditions of stress field. According to the results ofstress, displacement and plastic zone, this paper analyzes the influence of depth,horizontal stress direction, residual strength and softening modulus on thedeformation and failure of the roadway.(3) This paper analyzes the coupling relationship among stress field, seepagefield and temperature field, improves three equilibrium equations including rockstrain softening and elastoplastic coupling, and gets the corresponding finite elementequation form. Then numerical model is established by FLAC3D software under theconditions of stress field, seepage field and temperature field. According to the resultsof stress, displacement and plastic zone, this paper analyzes the influence of porepressure, porosity, temperature and convection coefficient on the deformation andfailure of the roadway. (4) This paper analyzes the influence of bolt length, anchorage length, anchorarrangement and sprayed concrete thickness on the roadway support, and study theeffect of the combined support include anchor, bolt and sprayed concrete on rockdeformation in the multi-field coupling roadway. The results show that this approachcan make the good supporting effect. Compared with no support, the relativedisplacement of the two side declines74.28%, the relative displacement of the roofand floor declines67.28%, the total displacement of the roof declines78.21%. Anchorsupport has a strong role on controlling residual area, sprayed concrete has a strongrole to improve the bearing capacity of the surrounding rock.