马坑铁矿岩体结构面对采空区围岩稳定性影响的研究

【作者】 冯环；

【导师】 饶运章；

【作者基本信息】 江西理工大学 ， 岩土工程， 2008， 硕士

【摘要】 岩体中广泛存在的、规模不等、产状不同、性质各异的结构面,劣化了工程岩体(围岩)的质量,影响了其稳定性。采矿工程中经常会形成各种形态的采空区,其围岩一旦失稳,将会导致顶板塌陷、冲击地压、生态环境破坏等严重危害。因此,对结构面的特性及采空区围岩稳定性的研究显得非常重要。本文结合“马坑铁矿采空区安全监测技术研究项目”课题,采用现场调查、理论分析、室内试验和数值模拟等研究方法,结合岩石力学理论与工程实践,对结构面及围岩进行了定性与定量研究,解决了企业生产难题,完善了工程岩体稳定性的研究方法。主要研究如下:1、采用详测线观测法,对矿区六个中段的岩体结构面进行了现场调查。结合实测资料,应用节理玫瑰图、赤平投影图等方法统计分析了结构面的发育特征。2、进行岩石力学性质室内试验,测定岩石力学参数。采用国标BQ体系和国际上通用的岩体地质力学RMR系统对矿区围岩稳定性进行分级研究,结果为一般。以岩石的试验结果为基础,经结构面弱化处理,推荐出岩体力学参数。3、利用有限元软件ANSYS对采空区含节理的围岩稳定性进行了模拟研究。结果表明目前采空区围岩处于相对稳定状态,但各中段采空区在空间位置上重叠的部位容易引起应力集中现象,存在安全隐患。更多还原

【Abstract】 The structural planes, exiting in rock with different scale, direction and character, not only degrade the quality but affect the stability of rock mass (ie, surronding rock mass). Once the surronding rock mass of the mined-out area formed with various shapes during the mineral exploiting process loses stability, there would arouse damages such as the roof subsidence, rock burst and environmental disruption. Therefore, it is very important to research the characteristics of structural plane and the stability of surrounding rock of mined-out areas.Combining with "the study on mined-out areas monitoring technology of Makeng iron mine in Fujian province", adopting manifold research methods such as in-site investigation, theoretical analysis, indoor mechanical testing and numerical simulation, associating rock mechanics theory with practice, the qualitative and quantitative study is accomplished, producing problems are resolved.The following are the main researches:First, through the method of detail scanline surveys, joints fissure in six mining levels are in-site investigated. With measured geological datas, the developing characters of structural planes are statistically studied by making joint rosette,stereographic projection and so on.Secend, the indoor mechanical testings are carried out to get the rock mechanics parameters. The stability of the surrounding rock mass is in ordinary level, the study is based on the BQ system and Geomechanics system (RMR) being popular in the world at present.Third, makes use the finite element sofeware ANSYS to analyse the stability of a certain mined-out area. Results indicate that the surrounding rock mass is in the state of relative stability at present, but the overlap where mined-out areas of every level meet each other in space is very easy to arouse stress concentration phenomenon, which threatened safe production in Makeng iron mine.更多还原