Study On Collaborative Control Of Interior And Exterior Bearing Structure For Typical Surrounding Rock Of Deep Roadway In Pingdingshan Mining Area

The occurrence environment of high temperature,high pressure,high permeability,strong mining disturbance,and strong time effect(“three highs and two strong”)in deep coal and rock mass has brought serious adverse effects on mine roadway support,which has been one of the hot issues concerned by the mining industry.As one of the typical deep mining areas in China,the mining depth of the main mine in Pingdingshan mining area has exceeded 800 m in varying degrees.The existing practice shows that the surrounding rock of deep roadway is soft and broken,and has the characteristics of large deformation and strong rheology.With the support technology of shallow roadway,the surrounding rock of roadway is difficult to maintain long-term stability.Therefore,it has important theoretical value and practical significance to systematically deepen the research on surrounding rock control technology of deep roadway in Pingdingshan mining area.In this paper,the field measurement,theoretical calculation,numerical simulation and industrial test methods are used to improve the selfsupporting capacity of surrounding rock.The mechanism and key technology of surrounding rock cooperative control are deeply studied,which can provide reference for the selection of support mode and the design of technical parameters of deep roadway.The main research results are as follows:(1)The distribution characteristics of tectonic stress in main production mines of Pingdingshan mining area are clear,and the structural characteristics and typical physical and mechanical characteristics of surrounding rock of deep mine roadway are mastered.Combined with the creep test results of surrounding rock,the threedimensional viscoelastic plastic constitutive model of surrounding rock creep and other confining pressure is deduced,and the universal analysis is carried out in many mines.Based on the in-situ measurement,the time-space evolution characteristics of strength,cohesion and elastic modulus attenuation of surrounding rock are analyzed,the strength attenuation model of surrounding rock is established,and the influence of lateral pressure coefficient on stress evolution and deformation of surrounding rock is studied.The overall failure characteristics of continuous contraction of full section,floor heave and two side convergence of deep roadway are mastered,which are significantly greater than roof subsidence.The location of the main bearing area of roadway surrounding rock is 2.4-3.0 m and its mechanical properties are defined.(2)Based on the synergetic bearing,support(force)synergetic effect and "support surrounding rock" synergetic control("three synergetic")of the interior and exterior bearing structure,support(force)synergetic effect and "support surrounding rock"(viscoelastic)elastoplastic mechanical model of the surrounding rock are established respectively,and the synergetic mechanism and main mechanism of the interior and exterior bearing structure of the deep roadway are studied The influence factors,the evolution law of deep roadway deformation with support time under different support strength is clarified,the "three coordination" control mechanism of interior and exterior bearing capacity of deep roadway surrounding rock in Pingdingshan mining area is revealed,and the reasonable support strength and time are determined.(3)According to the main influencing factors of deformation and failure of deep roadway in Pingdingshan mining area,the deep roadway in Pingdingshan mining area is divided into three types: high stress type,low strength type and composite type.The control idea of "collaborative support to build bearing structure,structural collaborative bearing to control surrounding rock deformation" is defined.The high strength support to strengthen the exterior bearing structure,grouting to modify the interior bearing structure and pressure relief to improve stress is defined The control countermeasures of "strong outside and stable inside" in the bearing circle of deep mine roadway are put forward.This paper puts forward the four in one key support technology with the core of double-layer shotcreting,anchor cable grouting,anchor cable shed support and floor pressure relief,develops the supporting materials and equipment,explores and improves the corresponding grouting technology measures,and forms the deep roadway surrounding rock interior and exterior collaborative load control technology system.(4)Combined with the characteristics of large-scale strong anchoring of new materials such as hot-rolled thick wall hollow grouting bolt,anchor cable and cement grouting additive,aiming at the control requirements of composite type,low strength type and high stress type roadway surrounding rock,based on the collaborative control technology system of interior and exterior bearing of deep roadway surrounding rock,the reasonable support mode,parameters and support time of three kinds of roadway are determined.The relationship between the deformation of surrounding rock on the roadway surface and the synergy efficiency is established.The synergy efficiency evaluation method based on the preexcavation support effect prediction and post excavation surrounding rock deformation early warning is proposed to guide the roadway support.The results show that the relevant technology can effectively improve the bearing capacity of the interior and exterior bearing structure,and the synergy efficiency of the three kinds of roadway interior and exterior bearing structure reaches,86.33%,80.8%,86.05% respectively,which significantly controls the surrounding rock deformation.This paper has 142 figures,20 tables and 182 references.