Research On The Distribution Law Of Separated Layer In Overlying Strata And The Methood Of Surface Subsidence Control In Coal Mine District

Surface subsidence damage in coal mining district is worse and worse and ithas an effect on the aspects such as farm production , people life, transportation andenvironmental hygiene with increasing of mining. This result explain that we badlydestructed the PRED coordination between man and the earth and made the resultsof air pollution, water attenuation, degradation of earth's ability and quantity and ofbuilding damage. In order to lower the endangerment of surface subsidence scholarshave researched time and time on the methods like letting up the quantity of surfacesubsidence by using propriety mining method, upkeep on building or the synthesisharnessing. The paper has systematical research on the distribution regulation ofseparated layer in overlying strata and the method of surface subsidence control incoal mining district in order to perfect the new method - the method of loweringdown surface subsidence by injecting clay grouts into separated layer in overlyingstrata. We have many works as following:1.This paper made the basis of practical application by researching on thephysical analogue and figures simulation analogue, and analyzed the process ofmining rods movement and damagment. This paper puts forward the mechanicalprocess of balance form of overlying rock. The process of balance is on thealternation of arch and beam (plate), explores the space-time law of separatedstrata's occurrence, development and distribution and this paper damasks theoverlying rock as injecting zone and no-injecting zone from the aspect of controllingoverlying rock.2.The separated strata is over fracture zone and under integral crook zone inwhere the rock formation's moving is of monolayer or of many layers more oftenthan not, and the thickness of strata is very small while comparing with integralcrook zone. The flexure of layer is smaller while comparing with its thicknessbecause of the finiteness of layer's fragility and coal seam's thickness. This paperstudies the mechanism of strata's occurrence, the size and position of strata and thedelineation of strata on the basis of mechanical theory and of what discussed above.At the same time the paper also discussed the computing method of strata Whilemining pitching coal.3.This paPer exPlored the influencing factors on the law of distribution anddemarked them tWo classes. The one is geologic condition including rock'shardness. interbed feature. hard lager's existence and its tosition. existence form ofinsedimentary rock. geology structure and fau1t. The other is mining technicalconditions including mining method. rate of depth and thickness. incidence of coalseam' size of mining dummy and mining sPeed and so on. The paPer also made thequantitative analysis or qualifies analysis at the rate of contribution.4.This paPer tentatively wrote the guide-book for lowering down thesubsidence by injecting clay grouts on the basis of practical use. The text explainsthe following all-sidedly and systematically such as the principle of how to definitethe position of hole. the making of hole and the organization of technical schedule.The paper gave out the method to design the injecting project as the example of onehole and one station. And the paPer also analyzed the action and fiowing law of claygrouts which was in the space of strata, and at the same time aPproached the methodto assess the result of injecting project.5.As the result of theory and technique, this paPer analyzed three examplesand pointed out the feature of using the technique in different coal seam. thetrustiness of injecting result and the target of project. This text further perfected thetheory and technique systems of strata's distribution law and of surface subsidencecontrol.