Research And Application Of Grouting Reinforcement Mechanism Of Surrounding Rock In Soft Fractured And Tectonics Roadway

Grouting reinforcement,as a method of surrounding rock control,has been widely used in mine surrounding rock control.Grouting reinforcement is especially suitable for the control of soft fractured and tectonics surrounding rock.However,due to the anisotropic property of the surrounding rock,the undiscoverable process of the grouting project,and the complexity of the interaction between the grout and the surrounding rock,causes the current surrounding rock of the soft fractured and tectonics Grouting reinforcement lacks theoretical guidance.Most grouting projects are designed and constructed based on engineering experience.The lag of grouting theory research has become the main bottleneck restricting the development of soft fractured and tectonics surrounding rock grouting project to the controllable and scientific direction.This paper relies on grouting to strengthen the actual project,comprehensive use of research methods combining theoretical analysis,numerical simulation and industrial experiments to study the problems related to grouting reinforcement of soft fractured and tectonics surrounding rock,and obtains some guiding conclusions.Based on the characteristics of the soft fractured and tectonics surrounding rock,it is divided into three types:joint-fractured developing surrounding rock,high-stress soft surrounding rock and tectonics area surrounding rock;Through numerical simulation,the analysis of stress and deformation of soft fractured and tectonics surrounding rock during the excavation and mining.it is concluded that when the roadway is excavated in the surrounding area of soft and broken structure,the plastic rock area of the surrounding rock has a large development range,and the two sides of the roadway will have a stress concentration phenomenon at 2?3.5m.Under the disturbance of mining pressure,the surrounding rock stress,the stress concentration of the two sides and the surface displacement of the roadway all gradually increase,and the deformation of the two sides is relatively large under the influence of mining.According to the analysis of the grouting reinforcement mechanism,it is concluded that when the jointed fractures develop surrounding rock and high-stress soft surrounding rock for grouting reinforcement,the grouting method is mainly fissure grouting,and the role of the slurry is mainly to strengthen the fractured structural surface and reinforce it,filling cement,compaction and skeleton support.When the surrounding rock of the tectonics area is reinforced by grouting,the grouting method is mainly fracture grouting,and the main functions of the slurry are compaction,split filling and skeleton support.According to the fracture grouting model of the tectonic surrounding rock mass and the supporting technology of the broken surrounding rock shell,establishing the load-bearing mechanical model of the shell after grouting,and deduction of critical bearing shell thickness to ensure the stability of tectonic surrounding rock,quantitative grouting reinforcement expression.Using 3DEC numerical simulation to analyze the relationship between grouting pressure,crack opening and slurry diffusion radius,it is concluded that the slurry diffusion radius gradually increases with the increase of grouting pressure.When using JCT composite grouting material for grouting,under different grouting pressures,the crack opening has different effects on the slurry diffusion.When the grouting pressure is 6 MPa,as the crack opening increases,the slurry under low pressure diffusion range is gradually reduced,and the diffusion under each pressure gradient is more uniform.According to the above research conclusions,the grouting reinforcement scheme design was carried out with the background of a mine 11~#coal belt conveyor main lane crossing faults and subsidence columns as the engineering background.Design grouting reinforcement scheme,include determined that the grouting reinforcement adopts a two-cycle grouting construction process,with a grouting depth of 3m,a drilling row spacing of 6m within each cycle,and a grouting pressure of 5?6MPa.During the implementation of grouting reinforcement,the ordinary two-cycle grouting construction was optimized to small-stage forward grouting,which solved the problem of easy leaking and plugging during the grouting process and ensured that the slurry was uniform within the grouting range.According to the evaluation of the effect after the grouting,it is concluded that the grouting reinforcement solves the problem of large deformation of the surrounding rock of the roadway,and the reinforcement effect is significant.