Analysis Of Influence Factors And Control Technology Of Roadway Floor Heave Under The Coupling Effect Of Stress And Seepage

The floor heave of the roadway is an important reason that restricts the safe production of coal mines.Due to the harsh and complex underground geological environment,the mechanism of the floor heave of the roadway is different.As the mining depth of coal resources increases,the pore water pressure of the environment in which the roadway is located gradually increases,and the impact of groundwater seepage on the stability of the roadway is increasingly prominent.The surrounding rock of the roadway will deform and fail under the combined action of the stress field and the seepage field.Considering the role of high ground stress can no longer reasonably explain and solve some roadway floor heave problems,and the coupling of stress-seepage needs to be considered.Taking the South Wing Auxiliary Shaft Bottom Depot of the Gaocheng Mine as the engineering background,field investigation,theoretical analysis and numerical simulation are used to study the influencing factors and control technology of the roadway floor heave under the coupling effect of stress-seepage.The main work and results are as follows:(1)Field investigation was conducted on the depot at the bottom of the auxiliary shaft of the south wing of the Gaocheng Mine,and the reasons for the bottom heave of the depot and roadway were analyzed based on the geological data of the mine and the damage of the roadway.Through numerical simulation methods,the deformation and failure state of the roadway floor before and after the impact of groundwater seepage is compared and analyzed.The results show that the damage and deformation of the roadway floor after considering the seepage effect are aggravated and the floor heave volume increases.(2 Combining elastoplastic mechanics and rock mechanics theoretical knowledge,a roadway mechanics model under the coupling of stress and seepage was established,and the buried depth of the roadway under the coupling of stress and seepage,the supporting resistance,the lithology of the surrounding rock of the roadway,and the original pore water were studied and analyzed.The influence of pressure and effective water pressure coefficient on the plastic zone range and displacement of the roadway.The calculation found that the greater the buried depth of the roadway,the greater the original pore water pressure and the effective water pressure coefficient,the greater the impact of seepage on the roadway’s failure and deformation;the nature and support of surrounding rock The stronger the resistance,the smaller the effect of seepage on the roadway’s failure and deformation.(3)The influence of the surrounding rock properties,original pore water pressure,and surrounding rock surface permeability on the floor heave of the roadway under the coupling effect of stress-seepage are studied separately by numerical simulation methods.The results show that the enhanced lithology of the roof of the roadway will make the horizontal stress of the roof higher than that of the bottom,and the bottom will play the role of pressure relief to reduce the bottom heave;the enhanced lithology of the slab will increase the plastic zone range of the surrounding rock of the slab,and the broken slab will be broken.The surrounding rock plays a role of pressure relief,and the horizontal stress transfers to the deep rock mass,thereby reducing the squeezing effect of the ledge on the bottom plate,causing the bottom plate to damage and reduce the bottom heave volume;the increased floor lithology can not only reduce the bottom heave volume,but also contain the bottom plate The cracks in the rock formations are developed to reduce the infiltration of pore water into the roadway;the increase of the original pore water pressure will increase the volume of the roadway floor heave.When the water pressure is small,the floor heave volume increases steadily and slowly.When the water pressure increases to a certain value,The floor will be severely damaged and the amount of floor heave will increase sharply;the closed support of the surrounding rock surface will reduce the permeability of the surrounding rock surface and reduce the infiltration of the pore water of the surrounding rock into the inside of the roadway.As the permeability of the surrounding rock surface decreases,the roadway floor will increase Tension damage will occur,and the floor heave of the roadway will increase.Floor lithology and original pore water pressure have the greatest impact on the floor heave of the roadway.(4)Based on the influencing factors of the roadway floor heave under the coupling of stress-seepage and inspired by other similar projects,based on the principle of "draining water pressure,strengthening the floor,and preventing water seepage",the technology of controlling the floor heave of the roadway under the coupling effect of stress-seepage is developed.the study.Drainage holes are set in the floor of the roadway to reduce the pore water pressure of the surrounding rock of the floor.Numerical simulation methods are used to study the influence of the depth of the drainage holes on the floor heave of the roadway.The results show that the depth of the drainage hole reaches a certain value and continues to increase its depth on the floor heave.The control effect will not be significantly improved.Three roadway support schemes are designed,and the effect of the three support schemes on the treatment of the bottom heave of the roadway under the coupling of stress and seepage is compared by numerical simulation,which provides a reference for other similar projects in the treatment of the bottom heave.