The Determination Of Roof Bedding Separation Critical Value Of Coal Mine Roadway Of 11-2 East Kouzi

Casualties caused by roof accidents in our country occupy a large proportion of all accidents. With the coal mining to the deep development, compound roof is widespread in China’s major coal mining area. Therefore, mastering the compound roof of roadway deformation law is very necessary, especially the determination of separation critical value for monitoring the roof bedding to ensure the stability of compound roof.Combined with the scene of typical compound roof of roadway, comprehended methods of a large number of field measurement and laboratory test and around two key problems that the determination of key stratum of roof bedding separation and the specific number of separation critical value, this paper respectively determines the influence of the key stratum on the stability of the roof bedding and the concept of using the key stratum, and the determination of roof bedding separation critical value. It comprehends separation critical value of key stratum and non-critical stratum to get separation critical value of the compound roof anchorage zone internal and external.Get more reasonable standard of judging stability through the use of multiple measuring points in the same cross section to determine the development laws of separation; determine strata distribution of compound roof and strata litho logy through the use of borehole camera and geological coring; get the larger separation position through the use of numerical simulation method; determine the key position of roadway roof which is easy to damage through using the method of field to monitor those roof; Get numerical value of each separation and conclude the critical value of the anchorage zone of separation through the use of multi-point displacement meter to monitor the key stratum and non-critical stratum; verify the development status of roof bedding separation through the use of borehole camera to realize visualized observation of separation development. From what have been discussed above, it may draw the following conclusions.(1) The geological condition of the roadway is complex and roof accidents frequently occur, thus to determine the reasonable critical value to monitor the roof bedding of the roadway is very necessary.(2) The monitoring results of the different locations of the same cross section show that the critical value of the deep roadway, which is only picked up of the separation numerical value in the middle of the roadway, is unreasonable. It should be that the roof bedding range of the roadway reaches half of the roadway’s width as the standard. At this point separation development of roadway can be controlled and can be concluded that the criterion is safe. As the Similar object of study of roof bedding can use the same criterion.(3) The early development of roadway separation is the destruction of the key stratum, then the separation numerical value of non-critical stratum increases gradually. It can be concluded the separation numerical value of the key stratum and non-critical stratum through the numerical simulation combined with field monitoring. Comprehensively the internal separation critical value of 11-2 coal roadway anchorage zone is 15 mm, and the external is 20 mm.(4) The mine records of anchorage zone of separation numerical value can be concluded that the determination of the critical value reasonably meet the requirements of roadway roof stability. Use borehole camera to record the roof bedding separation twice, observe the development of compound roof separation, and intuitively verify separation development.