Research Of Deformation Damage Characteristic And Monitoring In Daye Iron Mine Subsidence

Surface subsidence refers to a geological phenomenon that rock-soil mass under theaction of natural or human factors fell down and collapse pits (holes). At present, due to thecontinuous development of mineral resources, the surface subsidence problems become loomlarge. The surface deformation of underground mines becomes a research at home and abroadfor the complexity of geological structure which is studied from different angles with thesurface deformation movement regularity. What’s more, research in the surface deformationmonitoring also have certain development in recent years. Therefore, it is a significant andmeaningful project to understand the relation between the underground mining and theland-surface deformation.Based on previous data, this study took Daye iron mine subsidence area as backgroundand introduced its engineering geological environment. In this article, we focused on Tiemen-kan subsidence area, and detailedly analyzed the factors which influenced the fall downof subsidence area and the law of rock deformation, then we used Ansys numerical simulationanalysis the continuous mining of the influence of the subsidence, summarizes the rock andthe subsidence surface movement law of development based on the real-time monitoring ofsubsidence areas. Specific studies and conclusions are as follows:1.The geological structure background of Daye iron mine is discussed. The overallsituation was described using the data from field trips and indoor investigations. Also, thelithologic features of regional stratigraphy, the regional structural styles and the neotectonicactivities were summarized briefly. Afterwards, investigation and analysis of subsidence areaswere conducted, which provided the basis for the studies of rock mass deformation rules andthe analyses of numerical simulation;2.The paper focuses on the geometry characteristics of the subsidence areas, especiallythe summary and conclusion of rock mass deformation features. At first, geometrycharacteristics of the subsidence areas were analyzed. Further, reasons of subsidence areasformation, deformation rules of terrane and the structure types and failure mechanism rockmass were summarized in order to select the simulation software for numerical simulationanalysis on the subsidence areas;3.Numerical simulation methods and conclusions. We used Ansys software to simulate the collapse area surface subsidence caused by underground mining at present (-110mexcavation), and surface deformation due to underground mining end (to-170m-158m)two-stage. We established a two-dimensional numerical model to simulate the distribution andquantity size of stress field, displacement field and plastic field of the surface subsidence area.We studied the overall stability of the mining goaf rock, and the results showed that: a) theprimary stress of the earth’s surface and the empty area nearby increased with the increase ofcutting depth; b) at the end of the excavation, primary stress changed from "pressure-cut"model to "pull-scissors" model at the bottom of surface subsidence pit; c) The verticaldeformation is the main form; d)except the3rd subsidence area, other collapse pits hadnothing abnormal.