Study Of Movement Laws And Loading Behavior Of Overlying Strata With Large Mining Height

Mine roof management is the key point for coal safety production. Based on years ofpractice and study, the structure and deformation of overlying strata has been discovered, andformed mine surrounding rock control theory, as well as the key strata theory. With thedevelopment of great height mining, the researchers conducted deep research about the rockpressure behavior and strata layer deformation. However, lack of study about the key stratalayer load change and the rock pressure behavior under the compound effect of the double keystrata layers was found. Thus, the study of the rock pressure behavior of double key stratalayers and key strata load behavior of the great height mining would play an important role incoal safety production.Taking30101near shallow seam longwall face of Hanglaiwan coal mine as example,this paper conducted research on the great height mining working face and strata layerdeformation by utilizing theoretical analysis, equivalent material simulating and fieldobservation methods. Key strata theory and mechanics of elasticity are used to analyze therock pressure behavior on working face and ground pressure mechanism. The deformation ofoverlying strata and the abutment pressure distribution behaviors are simulated by usingequivalent material. The Fiber Bragg Grating sensing system for monitoring the deformationof the overlying strata was established in the similar material model test, and the system isapplied to monitor and analyze the deformation of the overlying strata. The pressuremechanism can be obtained by analyzing the working face rock pressure behavior andweighting mechanism based on key strata theory in ground control. The rock pressurebehavior can be obtained by analyzing the geological characteristics and field collected dataof30101working face.The study indicated that the underground pressure of the30101face in Hanglaiwan coalmine was intense, and the weighting strength was relatively large. The first weighting stepdistance of the basic roof is50m, and the average periodic weighting step distance was 14~20m. The periodic weighting step distance and its strength are with the character of largeand small circle change. By applying key strata theory in ground control, the rock pressurebehavior of30101fully mechanized face in Hanglaiwan Coal Mine can be analyzed. Theanalysis results fit well with the results from field observation and model experiment. Theprocess of deformation of overlying strata is simulated. In the similar material simulation test,FBG had a good performance on detecting the deformation of the overlying strata, andobtained the result that the key strata load in accord with negative exponential cosine functionwith the working face advance.