Reasonable width of coal pillar retaining in the lower section of ultra-long working face mining
The distribution characteristics of the lateral abutment pressure in the coal pillar of the ultra-long working face are studied,and the stress distribution in the coal pillar of the section is studied using the numerical simulation.The change law of the lateral abutment pressure is monitored by placing the borehole stress meter in the different depths of the coal pillar in the field section,and the scientific determination of width of the coal pillar is guided.To carry out the comprehensive moni-toring and analysis of the stability of roadway surrounding rock,we study the deformation and failure characteristics of road-way surrounding rock under the influence of mining on ultra-long working face,optimize supporting parameters,and ensure the smooth and safety of mining roadway on ultra-long working face.The results show that:the internal stress distribution of coal pillar presents three obvious concentrated stress distribution states at the right end of 11205 face,the left end of 11207 face and the coal pillar area,and the stress concentration effect is more obvious at the coal pillar location.Increasing the width of coal pillar can effectively improve the stress distribution state of coal pillar,but when the width of coal pillar ex-ceeds 16 m,a little change occurs.After the mining of the working face,the roof displacement of the goaf in the working face 11207 increases significantly,and the overall displacement becomes a fan-shaped subsidence centered on the coal pillar,indicating that the coal pillar supports the overlying strata.According to the numerical calculation results,it is more appropriate to know that the width of the coal pillar is 16m.From the failure strength of the roof and floor of the coal pillar,it can be seen that the coal pillar of 16～20 m should be retained.
ultra-long working facecoal pillar retainingreasonable widthstress distributionsurrounding rock stability
万方数据
维普
