工程开挖致使围岩

近年来,金川主力矿山二矿区随着采掘深度的不断加深以及双中段回采,水平矿柱与垂直矿柱已经形成,其地压显现明显,巷道工程变形破坏严重,个别严重地段经多次返修都无法正常使用,地表裂缝出现并加速扩展,采场与充填体时有冒顶发生。面对越来越严峻的实际情况,有必要对深部工程区域进行岩石力学问题深入细致的研究,对于地下工程来讲地应力是最为主要的影响因素,工程开挖致使围岩的应力重新分布。因此对于深部应力状态的研究以及应力环境与地下工程的关系的探讨显得尤为重要。本论文以金川公司科技攻关项目“金川矿区应力场与岩石力学研究”为依托,主要针对二矿区开展工作,通过对二矿区深部地质构造、岩石力学特性、构造应力场的现场调查和测试,以及室内试验和数字仿真模拟,研究了矿区应力分布,在此基础上结合地下实际工程,分析了重点工程的稳定性。主要进行了以下分析和研究工作:1.系统的收集、整理、分析前人原岩应力实测工作和岩石力学研究的成果;2.矿区深部的工程地质特征调查与分析研究;3.矿区深部地应力测量,矿区深部的应力作用特征及变化规律研究,矿区浅部与深部地应力特征的对比、分析;4.对矿区地应力场的有限元模拟分析研究;5.对重点工程稳定性的三维有限元模拟分析研究。获得了以下主要成果:1.根据本次地应力实测结果,结合前人所做的工作,并与数值模拟相结合,基本上构建了矿区深部应力作用平台,取得了良好的效果;2.通过综合分析研究,基本上了解了二矿区深部应力作用特征,并指出深部应力作用特征与浅部应力分布规律的不同之处,这种应力作用方式与工程实际变形破坏情况较好吻合,被实践所验证,本结果为地下工程的设计与施工提供了可靠的科学依据;3.在本文建立的地应力场的基础上,通过对重点巷道的变形破坏调查和监测,结合现场工程地质调查研究,利用ANSYS软件对所选取地段进行了三维模拟分析,进而分析巷道变形破坏的特征及原因,对于深部巷道工程的设计与建设有借鉴意义;4.在本文建立的地应力场的基础上,结合工程地质条件,利用有限元三维模拟分析,对水平矿柱与垂直矿柱的稳定性问题进行了初步研究。模拟分析制定了六种采掘比选方案,通过对六种方案的模拟及结果的研究对比,确定了优选方案,明确了矿柱开采过程中的应力变化情况,对矿柱在开采过程中的稳定性做出了初步判断,提出了现阶段进行矿柱开采的建设性意见。

活动房

In the recent years, with the increasing excavation depth and the truth of double-level mining, drifts were strongly deformed and severely damaged in the second mine block in the Jinchuan mine. Some drifts couldn’t be used normally even being repaired for many times. The geostatic emergence is very obvious. The crevasses in the surface have been occurred and enlarged quickly. Sometimes there is caving in the stope and the filling bodies. It is necessary to study on the rock mechanics problems in the deep engineering area. The stress is one of the most important factors to affect the underground engineering. Engineering excavation will result in re-distribution of the stress in the surrounding rock. So it is very important to study the stress condition in the deep mine area and the relationship between the stress state and the underground engineering.This paper relies on the technological project of the Jinchuan Company“Study on the Stress Field and the Rock Mechanics in Jinchuan mine”. The work is mainly in the second mine block. We have done a lot of work such as engineering investigation, the characteristic of rock mechanics and the tectonic stress field in the second mine block. We have also done the indoor experiment and numerical simulation. Through those works, we grasp the stress distribution in the mining Area. On the basis of this knowledge, combining the underground project reality we analyze the stability of the key project.The main works which we have done are drawn as follows:1. Systematically collect and analyze the data of the stress and the rock mechanics which were done by the predecessors.2. Investigate and analyze the engineering geologic characteristic in the mining area.3. Stress measurements were made at different structural position and depths and in different rock. Base on the results of stress measurements to study on the characteristics of the action of the stress in the mining area. And the stress characteristics of in deep level compare with in shallow level in the mining area.4. Study on the finite element simulation of the stress field of the mining area.5. Research on the tri-dimensional finite element simulation of the stability of the key project.Based on the above works some conclusions are drawn as follows:1. Based on the results of the stress measurement, to construct the stress field by the numerical simulation in the deep level in the mining area.2. The results of the stress measurement indicate that characteristics of the action of the stress in the deep level of the second mine block. And it can also be seen that the characteristics of the action of the stress difference between the in the deep and in the shallow. The results of the stress measurement well coincides with the actual deformation and damage in the project. The results offer the reliable scientific foundation for the design and the construction of the underground project.3. On the basis of the stress field which is founded in this paper, through the survey and the monitoring of the deformation of the key drifts, combining the engineering geological investigation and the software ANSYS to do the tri-dimensional simulation analysis for the chosen sectors to analyze the main reasons of deformation and damage of the drift. These works is important for the upgrading of design and the stability of the project in the deep level in the mining area .4. Base on the results of the stress measurement combining the engineering geological condition and the finite element tri-dimensional simulating to elementary study the stability problems of the horizontal and the vertical jambs. These simulation analyses establish six digging schemes. The results of simulation indicate that the stress changes during the jambs excavation procedure. Also the six schemes compare with each other to determine the preferred scheme. The elementary judgment of the stability of the jambs during the excavation procedure and suggestions for the jambs excavation are made nowadays.