| With the development of society,the scale of coal mining and the depth of mining has increased,Th e environment of the roadway is also becoming more and more complicated,the stress is getting higher,and The surrounding rock of roadway is more and more broken.Whether these problems can be effectively solved is related to the safe production of deep coal mines.After years of research by scholars,a lot of results have been achieved in the surrounding rock control of high-stress soft rock roadways,but it is still not perfect in engineering practice.For example,one-time support is difficult to meet the support needs of high-stress soft rock roadway,and it needs to be repaired or re-supported.Pressure relief support cannot achieve the purpose of pressure relief without reducing its own carrying capacity.The amount of deformation of the collapsible support cannot meet the deformation requirements of the soft rock roadway.These problems have brought many problems to the surrounding rock control of high-stress soft rock roadways Therefore,it is necessary to study the deformation and failure characteristics and failure mechanism of surrounding rock in high-stress soft rock roadway,and propose a new and effective control concept of surrounding rock.It is very important to control the surrounding rock of high stress soft rock roadway.This paper takes Majialiang Mine 4# coal as the engineering background,adopts on-site investigation,theoretical analysis,physical similarity simulation,numerical simulation,and on-site industrial practice to summarize the destruction characteristics and influencing factors of the high-stress soft rock roadway.The failure mechanism of stress soft rock roadway,the "rigid-flexible-rigid" pressure relief energy absorption support concept and support scheme suitable for high stress soft rock roadway to control surrounding rock deformation are proposed,and through physical similarity simulation test and numerical simulation And onsite industrial practice has been verified.The main research results are as follows:(1)The transportation roadway and return airway of Majialiang Coal Mine No.4 have obvious high-stress soft rock roadway characteristics,and include three roadways with different surrounding rock structures required by the fund.By conducting field investigations on the roadways under three surrounding rock structures,summarizing and comparing the failure characteristics of the surrounding rock and the magnitude of the approaching amount of the surrounding rock,and finally selecting the roadway with the worst surrounding rock conditions and the most severe degree of fracture as the focus of this study,namely the roof The lithology is weaker than the two gangs.(2)Based on the observation of the failure characteristics of the roadway under the original support form and summarizing,the following characteristics of the surrounding rock failure of the high-stress soft rock roadway are obtained.1)The excavation of the roadway is fast after the excavation,and the mine pressure appears violent;2)The initial deformation is large;3)The existing support forms cannot meet the requirements of surrounding rock deformation,and it is difficult to form the roadway support of the soft rock roadway once,requiring secondary Support and repair.(3)A constitutive model of surrounding rock damage in soft rock roadway is established,and the stress and displacement expressions of the completely elastic zone,elastoplastic damage zone and completely damaged zone of the roadway surrounding rock are obtained through mechanical analysis.(4)From the perspective of energy,the principle of hole release and pressure release in high stress soft rock roadway was explained,and the construction principle of hole release and pressure release support was given,and the pressure release was simulated and studied.The influence of the layer size and U-shaped steel model on the surrounding rock deformation of the roadway,the optimal pressure release hole and U-shaped steel model were determined,and based on the nonlinear creep model,the plastic area of the surrounding rock under the optimized scheme and the displacement variation were simulated.The change law of excavation time verified the reliability of the support parameters of the optimization scheme.(5)Combining with the engineering practice of Majialiang Coal Mine,a “rigid-flexible” pressure-relieving energy-absorbing support system with the core of pressure-releasing theory as the core was proposed,briefly describing the relationship between the two,and optimizing the belt transportation The support form and parameters of the roadway are simulated to study the influence of the spacing between the bolts and the length on the deformation of the surrounding rock,and the reasonable recommended values of the anchoring parameters are given.(6)According to a certain similarity ratio,the single-axis loading method is used to simulate the use of anchor rod + anchor cable,anchor rod + anchor cable + steel bracket,anchor rod + anchor cable + steel bracket + pressure relief material for soft rock roadway.The destruction characteristics and destruction rules of the roadway in a supporting scheme.According to the comparison of the destruction results of the tunnel under the traditional support scheme and the pressure relief energy absorption support scheme,the reliability of the "rigid and flexible" pressure relief energy absorption support scheme was initially verified.(7)Conducted on-site industrial test of the research results,applied "rigid and flexible" pressure relief and energy absorption support scheme to the transportation roadway of No.4 coal in Majialiang Coal Mine,and monitored the displacement and separation of surrounding rock of the roadway,according to the comparison The results further verify the superiority of the "rigid and flexible" pressure relief energy-absorbing support scheme. |
PDF Full Text Request