1、英文原文Overlying Strata Movement Law in Fully Mechanized Coal Mining and Backfilling Longwall Face by Similar Physical SimulationH. Yanli, Z. Jixiong, A. Baifu, and Z. Qiang School of Mining, China University of Mining & Technology, Xuzhou, ChinaReceived August 7, 2011Abstract Fully mechanized coal min
2、ing and backfilling technology with gangue, fly ash and losses etc. changes the overlying strata movement characteristics and strata behavior law in the fully mechanized coal mining and backfilling longwall face (FMCMBLF). Based on the similar theory, a model of the overlying strata movement in FMCM
3、BLF is established with sponge and plastic foam whose thickness ratio is 1:2 as the similar backfilling body. From the similar physical simulation, the following conclusions have been drawn: (i). The overlying strata movement develops from bottom to top as the mining progresses in the FMCMBLF and co
4、nsequently, the subsidence curve of the strata assumes symmetrical bowl. (ii) No caving zone but only fissured and bended zones are found in the overlying strata herein. (iii) The subsidence velocity undergoes a changing process of “minimum, successive accretion, reduction, and stabilization,” and t
5、he overburden strata movement lasts for a long time. The test results would provide reference for further research of strata control as well as fully mechanized coal mining and solid backfilling technology.Keywords: overlying strata movement law, similar physical simulation, backfilling bodyINTRODUC
6、TIONWith rapid development of national economy and increasing demand for coal resources in China, it is of great importance to study how to extract coal under buildings, railroads and water bodies. Fully mechanized coal mining and backfilling technology with gangue, fly ash and loess etc. is an effe
7、ctive method in this regard. It would not only effectively control the overlying strata movement and limit surface subsidence, but make full use of gangue, fly ash and other solid waste, thus providing a reliable and green mining technologic solution 1-4 to solve problems concerning coal mining, env
8、ironmental protection and sustainable development of mining areas. In this technique, mined-out gobs(or gobs)are filled with gangue, fly ash and other solid waste as permanent supporting body to bear the weight of the overlying strata whose movement characteristics and strata behavior law are thus c
9、hanged in the fully mechanized coal mining and backfilling longwall face(FMCMBLF) 5-10. In this sense, it is of great theoretical and practical significance to conduct further research with regard to overlying strata movement characteristics (OSMC) and strata behavior law (SBL) in FMCMBLF.Major meth
10、ods to study OSMC and SBL are theoretical analysis, field measurement, numerical simulation, similar physical simulation, et al. Thereinto, simulation experiment with similar materials is an effective way in solving such problems and hence widely applied since specific problems may be addressed and
11、valuable results may be achieved with the help of the test 11-16.Guided by the similar theory, the test uses structural physical parameters of similar materials and similar engineering models. By essence, it makes models of the overlying strata, which are reduced by certain rate, with similar materi
12、als to simulate coal mining and observe the movement and damage of the overburden.The experiment results herein are useful in analyzing and predicting characteristics of strata movement and deformation in actual mining. Among other items, similar physical simulation may, in the short term, reflect a
13、 comprehensive process of engineering mechanics and geotechnical deformation patterns. Its conditions are easily controlled and strata and surface movement directly perceived. In this sense, the simulation test is suitable for qualitative studies. The article herein takes sponge and plastic foam as
14、similar backfilling body to simulate the OSMC 17 in FMCMBLF, thus providing reference for further research of strata control as well as fully mechanized coal mining and solid backfilling technology.1.SIMILAR PHYSICAL SIMULATION TEST OF OSMC IN FMCMBLF1.1. Model establishment with similar materialAcc
15、ording to the mechanical characteristics of coal mining and solid backfilling, the model is reduced to be two-dimensional whose geometric length, thickness and height are respectively 2.5 m,0.2 m, 1.1 m and enrichment rate 100%. By analyzing a drill bore column next to the first mining and backfilli
16、ng face of the fourth panel in southern Tunlan coalmine, we get its strata distribution as shown in Table 1.To better reflect the movement and damage characteristics of the overburden, the geologic column of the model is, to some extent, simplified and modified on the basis of real lithology in the panel. The similarity parameters of the simulation test are listed below the above similari
