| At present,shallow coal resources in China tend to be exhausted,and deep mining becomes an inevitable trend.With the continuous extension of mining depth and mechanical automated mining strength increase,in the deep soft rock tunnel surrounding rock of coal seam mining process in the process of excavation shows the characteristics of high ground stress and cross section deformation serious,makes it hard for a supporting of roadway surrounding rock forming,difficult to support,and late may be due to dynamic pressure effect of the stope support harder.Therefore,roof support of roadway supporting coal has become a key technical problem to be solved in the safe and efficient production of some mines.Mine based on the second mining area 1201 mining face transport gateway as the research object,based on the working face roadway engineering geological conditions,the in-situ monitoring and laboratory experiments,the comprehensive methods such as numerical simulation and industrial test,the deformation of surrounding rock of roadway in collecting and sorting the information based on the deformation and failure characteristics of surrounding rock of roadway is obtained and analyzed the reasons and influencing factors of its deformation and destruction.Then,three different supporting schemes of roadway surrounding rock roof are proposed.FLAC3 D software is used to simulate the stress distribution,displacement and plastic zone range of roadway surrounding rock.After comparative analysis of the supporting effect of each supporting scheme,the best scheme is selected.Finally,the industrial test was carried out and verified,and the following conclusions were obtained:(1)By means of field monitoring,laboratory rock mechanics experiment and numerical simulation,the deformation and failure characteristics of roadway surrounding rock are obtained,and the causes and influencing factors of roadway deformation and failure are analyzed.It is concluded that the serious deformation and failure of roadway roof is the main factor affecting the rapid tunneling of roadway.The deformation causes mainly include: First,the strength of the coal body and the rock layer at the top of the coal seam is low,and the roadway is driven along the bottom,and the top coal is about 6m above,which is difficult to support;Second,the numerical simulation and theoretical calculation results show that the original supporting mode and supporting parameters of roadway are not reasonable.(2)Three kinds of surrounding rock control technology schemes were proposed,and FLAC3 D was used to simulate three kinds of surrounding rock control technology schemes.The supporting effects of the three schemes were compared and analyzed,and the supporting scheme of "anchor cable +W steel belt +U steel + grouting" was optimized,and the roof and two sides under the support were 82.7mm and 153.1mm,respectively.Compared with the original scheme,the control effect of surrounding rock is better.(3)The field industrial test shows that through the field monitoring data in the test section,the average roof movement is about 82.8mm and the average two-side movement is about 147.2mm within 60 days of monitoring,which are reduced by70.5% and 69.3% respectively compared with the original scheme.Therefore,the optimization scheme has a good effect on the control of roadway surrounding rock,and the deformation is within the design allowable range,which ensures the stability of roadway.62 figures,5 tables,and 68 references. |
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