Study On The Settlement Regularity Caused By Deep Caving Method

Rock caving and surface subsidence caused by caving method is a complex relationship between spatial and time. With the gradual increase of mining depth, because of the complexity of the geological conditions and the influence of tectonic stress, In the process of the underground mining, displacement angle of strata and subsidence angle were hard to predict, which may cause unreasonable mine construction planning, affacting the normal safety production in mines. In this paper, the actual situation of Anshan Chentaigou Iron Mine caving mining was the research background, on the basis of theoretical studies, field surveys and test, the systematic study has carried on the rock and ground movement regularity caused by caving mining by using finite difference Software FLAC3D and discrete element software 3DEC, combined with empirical evaluation means. The main work and research contents are as follows:1.Using the drilling core of ZK-25、SK1 and ZK-14, by rock mechanics experiments, geting the basic mechanical properties of Chentaigou rocks.Combining with field borehole camera and drill core logging, based on the traditional RMR logging method, the rock mass quality classification of Chentaigou mining area was obtained. Using the generalized modified Hoek-Brown strength criterion, the field rock mass Mohr-Coloumb strength parameters was obtained by transforming, and it provides the calculation parameters to subsequent numerical calculation.2. The ground stress of ZK-25 in the north of mining area and ZK-28 in the middle of mining area was tested by using hydraulic fracturing technique, which obtained a good reliability test data. On the basis of test results, based on the principle of artificial neural network and displacement back-analysis, the displacement boundary conditions was inversed.3. Based on continuum theory, The displacement field and stress field in the process of mining were simulated by using finite difference software FLAC3D. The surface subsidence laws under the influence of the fault in the process of the excavation and the distribution characteristics of stress field and finally determines rock displacement angle after the first stage of the excavation was obtained.4. Based on discontinuous theory, by using the discrete element method software 3DEC, different joint Angle, lateral pressure coefficient and the moving characteristics of rock under different excavation stage was respectively simulated. the basic movement regularity and displacement angle were obtained.5.Combined with the empirical evaluation method, comprehensively, the th-ree met hods were investigated. The rock displacement angle and the scope of s-urface subsiden ce by these three methods were eventually given.