Study On Surrounding Rock Stabilization Control Of Intensive And Coordinative Support In Deep Cracked Roadways

The support problems of high stress roadway in the deep coal mine have not beensolved completely so far, and the support problems of the high stress broken surroundingrock are increasingly prominent especially. The difficulty of surrounding rock control has astrong impact on the safety production and construction costs. There is great significance inresearching the stability mechanisms and control technology of high stress roadway forengineering application. Consequently, taking the railway downhill of eighth mining area inQian Jiaying mine for the engineering background, the coordinate support mechanisms andcontrol technology of high stiffness support and anchor cable in deep high stress roadwaywere studied systematically by the methods of numerical simulation, theoretical analysis,laboratory simulation test, field measurement and industrial practice. And the achievementswere successfully applied in high stress broken surrounding rock of roadway. The maininnovative achievements are as follow:(1) The triaxial compression creep tests of siltstone were carried out. The tandem creepmechanics model of generalized Kelvin and nonlinearity viscoplastic body NVPB wasproposed firstly, and the constitutive equation of creep model was deduced. The5parameters of this model were identified by nonlinear regression analysis based on creep testresults. The subroutines secondary developed was taken to the finite element softwareABAQUS to analyze the deformation rules of roadway and the stability failure cause ofpassive support steel frame.(2) The ideology of high stiffness support and anchor cable coordinate support wasproposed on the basis of primary and secondary bearing zone theory, and the mechanicalmodel of support and anchor cable coordinate support was also established, and the stabilityof the support structures in different working conditions were studied, and the principle ofanchor cable coordinate support was proposed. Based on the strain softening elastic-plasticanalysis of circular roadway, the design length of anchor cable and support time wasconfirmed.(3) The capacity of concrete filled steel tube support was analyzed by physicalsimulation test and numerical simulation methods. The stress distribution laws anddeformation behaviors of concrete filled steel tube support and anchor cable were achievedin different working conditions, and the design key points of concrete filled steel tubesupport and anchor cable support were achieved by discussing the influence rules of supportparameters on bearing capacity. (4) The numerical analysis method is adopted to study the stability mechanisms ofsurrounding rock with concrete filled steel tube support and anchor cable coordinate supportstructure, and the change laws of plastic zone with the support structure and load steps wereobtained, revealing the control effects of anchor cable prestress over the surrounding rock.(5) For the existing problems of the railway downhill of eighth mining area in QianJiaying mine, the coordinating support scheme including primary bolt-mesh-shotcretesupport, reserving deformation space, back filling of frame, concrete filled steel tube supportand anchor cable was confirmed based on the theories and techniques of high stiffnessconcrete filled steel tube support and anchor cable coordinate support. The engineeringpractice showed that the coordinating support scheme could effectively control the severedeformation and ensure the stability of surrounding rock.