Stability Analysis And Control Technology Of Surrounding Rock In The Cooling Electric Chamber Of Guobei Coal Mine

With the continuous increase of coal mining depth and chamber section size,the difficulty of chamber support is getting higher and higher.The mutual intersection between chambers makes the stress field of surrounding rock more complicated,leading to the support method that was successfully used in the original shallow part.It is not completely suitable for deep chambers.In this thesis,the surrounding rock stability and control problems of the needle chamber are studied in the deep part by using the cooling electromechanical chamber of the Wobei Mine as the research background,comprehensively using laboratory tests,theoretical analysis,numerical simulation,onsite monitoring,and on-site industrial tests.The factors affecting the stability of surrounding rock in large-section chambers,the stability of surrounding rock in adjacent chambers at different spacings,and the displacement and deformation characteristics of surrounding rock at various locations in the cooling electromechanical chamber,combined with the actual conditions on site,put forward corresponding measures for areas with poor surrounding rock stability.The main research results of the surrounding rock stability control technology are as follows:(1)The study analyzed the influence of different factors on the displacement of the surrounding rock of the chamber,and it was concluded that the displacement of the surrounding rock increased with the increase of the initial stress and the size of the chamber section,and with the shear modulus and internal friction of the surrounding rock.The angle and the internal force of the support increase and decrease.Through numerical simulation,the influence of chamber height-to-width ratio on the stability of surrounding rock is determined.Under the condition of a certain section size,with the increase of the height-to-width ratio,the displacement of the surrounding rock of the roof and floor gradually decreases,while the surrounding rock The amount of rock displacement gradually increased.(2)Using the stress distribution calculation formula of a single circular chamber,the mutual influence of different chamber spacings is analyzed,and the reasonable spacing between chambers is obtained.The influence of adjacent chamber spacing on the stress field and displacement field distribution of the surrounding rock of the chamber was studied by numerical simulation,and it was determined that as the chamber spacing decreased,the mutual influence area between the chambers gradually expanded from the side wall of the rock pillar to Top floor position.(3)The mechanical model of the chamber rock pillar is analyzed,and it is determined that increasing the width of the rock pillar and reducing the chamber span can effectively reduce the stress of the rock pillar and improve the stability of the rock pillar.Using numerical simulation,the distribution characteristics of the plastic zone,stress field and displacement field of each chamber in the cooling electromechanical chamber are studied,and the expansion depth,stress distribution and displacement of the surrounding rock plastic zone at the junction of the chamber are analyzed,and the With the increase of the lateral pressure coefficient,the range and depth of the plastic zone of the roof and floor surrounding rock at the intersection of the chamber gradually increase,the vertical stress on the two sides of the chamber gradually decreases,and the displacement of the surrounding rock at the side of the chamber gradually increases.(4)Based on the field investigation and numerical simulation research,it is proposed that the surrounding rock of the cooling electromechanical chamber adopts the anchor mesh and cable shotcrete combined with layered grouting support technology,and the foundation bottom plate support under the equipment adopts "concrete casting+highstrength anchor mesh and cable" support.Protection technology,and structural compensation through anchor cables with beams.Field observations show that the use of this support scheme can effectively maintain the stability of the surrounding rock of the cooling electromechanical chamber.Figure 71,Table11,references 86...