晋宁磷矿层状边坡变形失稳机理研究

发布时间：2018-11-28 08:38

【摘要】：层状边坡的变形失稳机理研究是一个系统工程,包括层状边坡稳定性影响因素分析,研究区工程岩体稳定性分析及变形失稳机理研究,数值模拟分析方法等,单独就某一方面进行研究都不能全面地认识其变形失稳机理。本文以晋宁磷矿层状边坡变形失稳机理研究为题,从理论分析、力学分析、数值模拟等角度,对层状边坡的变形失稳机理展开深入系统的探讨,具体内容如下：(1)对层状岩体的力学特性进行探究,包括层状岩体的变形与强度各向异性以及结构面的力学特性。以层状岩体的力学特性为理论基础,主要分析了影响层状边坡稳定性的各个因素,即岩体应力、岩层倾角、地层岩性组合、岩体强度、水、边坡形态、震动、人为因素及其他。同时使用FLAC/SLOPE建立模型,着重对影响边坡稳定性的内因进行单因素影响性分析,即岩层倾角、放坡坡角、岩层层厚、岩体强度、层面强度、岩层产状变化等。(2)基于晋宁磷矿露天开采技术条件,结合对边坡变形破坏特征的统计调查,对现场的滑坡特征进行总结。对岩体结构面进行量测,采用Rocscience Dips软件将砂页岩分为三组优势结构面,分别为层面和两组节理面。对优势结构面总体几何特征进行统计分析,借助SPSS对分组处理后的数据进行频数直方图的绘制与均值、标准差的计算,得出三组优势结构面的产状,且验证优势结构面的变化均服从正态分布。最后使用赤平极射投影对现场边坡的稳定性进行评价,得出层面是影响边坡稳定性的优势结构面。分析矿山层状边坡变形失稳的演化过程,确定边坡“滑移—弯曲—剪出破坏”的失稳机理及高速平面滑动的失稳模式,从力学角度对层状边坡稳定性影响因素进行研究。(3)使用FLAC3D对层状边坡进行建模,然后从位移场、应力场、剪应变特征等方面对边坡岩土体的力学响应特性进行分析得出,随着边坡开挖施工的进行,开挖面附近的坡缘及产状变化点处位移最大。高边坡在开采过程中位移量逐渐增大,岩体向下滑移使其在产状变化点处受到强烈挤压而扩容,滑移面逐渐贯通并发展为滑坡。这种滑坡通常具有崩滑的特性,边坡变形破坏的演化过程证明了“滑移—弯曲—剪出破坏”的失稳机理,失稳模式呈现出高位剪出后的高速平面滑动。(4)露天矿边坡的防治和加固是一个复杂的系统性工程,在查清边坡工程地质条件的基础上,分析层状边坡的变形失稳机理,然后遵循露天开采的特点,提出拦、排、稳、固等滑坡防治措施,在局部区域采取顺层清方、抗滑桩、锚杆、注浆、防排水等综合措施进行加固,确保边坡在采矿期限内保持整体的稳定性。
[Abstract]:The study of deformation and instability mechanism of layered slope is a systematic project, which includes the analysis of the influencing factors of the stability of layered slope, the stability analysis of engineering rock mass and the mechanism of deformation instability in the study area, the numerical simulation analysis method, etc. The mechanism of deformation instability can not be fully understood by a single study on one aspect. In this paper, the deformation and instability mechanism of the layered slope of Jinning Phosphate Mine is discussed systematically from the angle of theoretical analysis, mechanical analysis and numerical simulation. The main contents are as follows: (1) the mechanical properties of layered rock mass are studied, including deformation and strength anisotropy of layered rock mass and mechanical properties of structural plane. Based on the mechanical properties of layered rock mass, the factors affecting the stability of layered slope are analyzed, including rock mass stress, rock dip angle, stratigraphic lithology combination, rock mass strength, water, slope shape, vibration, artificial factors and other factors. At the same time, the FLAC/SLOPE model is used to analyze the single factor influencing the stability of the slope, that is, the slope angle, the thickness of the rock layer, the strength of the rock mass and the strength of the layer. (2) based on the technical conditions of open-pit mining in Jinning Phosphate Mine, combined with the statistical investigation on the characteristics of slope deformation and failure, the landslide characteristics in the field are summarized. The rock mass structural plane is measured and the sand shale is divided into three groups of dominant structural planes by Rocscience Dips software, which are plane and two sets of joints respectively. Based on the statistical analysis of the total geometric characteristics of the dominant structural plane, the frequency histogram and the mean value and standard deviation of the processed data are drawn with the help of SPSS, and the occurrence of the three groups of dominant structural surfaces is obtained. And it is verified that the change of the dominant structure surface is obeyed from the normal distribution. Finally, the plane projection is used to evaluate the stability of the slope in situ, and it is concluded that the plane is the dominant structural plane that affects the stability of the slope. This paper analyzes the evolution process of the deformation and instability of the layered slope in mines, and determines the instability mechanism of the slope "slip-bending and shearing failure" and the instability model of the high-speed plane sliding. The factors affecting the stability of layered slope are studied from the mechanical point of view. (3) FLAC3D is used to model the layered slope, and then the mechanical response characteristics of rock and soil are analyzed from the displacement field, stress field, shear strain characteristics and so on. With the construction of slope excavation, the displacement of slope edge and occurrence change point near excavating surface is the largest. The displacement of the high slope increases gradually during the mining process, and the downward slip of the rock mass causes it to be squeezed and expanded at the occurrence change point, and the slip plane is gradually through and developed into a landslide. This kind of landslide usually has the characteristics of collapse and slip. The evolution process of slope deformation and failure proves the mechanism of "slipping-bending and shearing failure". The instability mode presents high speed plane sliding after high shear. (4) the prevention and reinforcement of slope in open-pit mine is a complicated systematic project. Based on the investigation of the engineering geological conditions of slope, the deformation and instability mechanism of layered slope is analyzed. Then follow the characteristics of open-pit mining, put forward prevention and control measures for landslide, such as blocking, drainage, stabilization and fixation, and take comprehensive measures in local areas, such as clear side, anti-slide pile, anchor rod, grouting, waterproofing and drainage, to reinforce the local area. Ensure the overall stability of the slope during the mining period.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD87

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