拟建普朗铜矿尾矿库库区地质构造对岩溶发育的控制及工程影响
发布时间：2019-01-09 14:02
【摘要】：拟建普朗铜矿尾矿库库区地处三江并流世界自然遗产地边缘,大地构造位置隶属三江特提斯构造域义敦弧南部中旬弧,库区地质构造复杂,可溶性岩石(碳酸盐岩)占据库总面积80%以上,在工程勘察过程中,重点关注了拟建项目区最突出的工程地质问题—岩溶问题。强烈发育的岩溶对尾矿库地基的稳定性、未来尾矿库渗漏,造成了潜在的安全隐患。因此,开展库区岩溶的发育特征和规律、控制因素,尤其是地质构造对岩溶的控制作用及其对工程建设的影响等方面研究,是一项必不可少的而且十分重要的工作,从而为下一步进行尾矿库建设提供可靠基础地质依据。本文在野外现场基础地质和水文工程地质调查及工程勘察的基础上,结合地球物理方法,研究库区区域地质背景、地质构造特征、可溶岩分布特征、岩溶发育特征及规律,系统深入地研究了拟建尾矿库库区及其周边区域岩溶发育的主导控制因素—地质构造。采用有限元方法,利用ANSYS计算软件,开展库区构造-岩溶在填筑工况下三维数值模拟分析,研究溶洞力学和变形情况,分析岩溶发育对工程建设的影响。研究表明：库区地质构造类型以褶皱构造、断层构造和节理构造为主,它们控制了工程区的岩溶发育。平面上,不同类型的地质构造组成了呈NW-SE方向展布的平行列式构造组合样式；剖面上,形成了对冲式构造组合样式。从燕山中晚期至今,区内构造应力场经历了NE→近SN→EW→NN W向多期构造应力场转变。工程区内岩溶类型以岩溶土洞(地表岩溶)和水平溶洞(地下岩溶)为主,在中三叠统尼汝组(T2n2)灰岩分布区,岩溶土洞在库区沿构造脊线、节理裂隙呈近SN-NW向三个带状分布,且发育集中,多呈串珠状分布。在发育强度上,在热绒背斜轴部、热绒-赤昌断层(F1)与热绒背斜复合带、F2和F4断裂交叉钳状出口处最为强烈。水平溶洞主要沿横张节理或纵张节理发育。采用有限元方法,利用ANSYS计算软件进行三维数值模拟表明,水平溶洞在填筑工况下均产生一定变形和位移,究其原因主要是因为区内岩溶的强烈发育,使得基岩面起伏不平,上覆土层厚薄不均,引起库区地基不均匀沉降。在工程作用下,局部地区有发生塌陷的可能,从而引起渗漏。在工程建设或运营过程中,必须充分考虑到这一岩溶地质灾害,采取必要防治措施。
[Abstract]:The reservoir area of the tailings of Plang Copper Mine is located at the edge of the world natural heritage site of the Sanjiang parallel flow, and the geotectonic position belongs to the middle arc of the southern part of the Yidun Arc in the Tethys tectonic domain of Sanjiang River. The geological structure of the reservoir area is complex. The soluble rock (carbonate rock) accounts for more than 80% of the total area of the reservoir. In the process of engineering investigation, the most prominent engineering geological problem in the proposed project area is karst. The stability of the tailing reservoir foundation and the leakage of the tailings reservoir are caused by the strong karst. Therefore, it is necessary and important to study the characteristics and laws of karst development in reservoir area, control factors, especially the controlling effect of geological structure on karst and its influence on engineering construction. So as to provide a reliable geological basis for the construction of tailings reservoir. On the basis of the basic geological and hydrological engineering geological survey and engineering investigation in the field, combined with geophysical methods, this paper studies the regional geological background, geological structural characteristics, soluble rock distribution characteristics, karst development characteristics and laws in the reservoir area. The geological structure is the main controlling factor of karst development in the proposed tailings reservoir area and its surrounding area. By using finite element method and ANSYS software, the three-dimensional numerical simulation analysis of tectonic-karst in reservoir area under the condition of filling is carried out, and the mechanics and deformation of karst cave are studied, and the influence of karst development on engineering construction is analyzed. The study shows that the main types of geological structures in the reservoir area are fold structure, fault structure and joint structure, which control the karst development in the engineering area. On the plane, different types of geological structures are composed of flat determinant structural assemblages distributed in the NW-SE direction, and hedge-type structural assemblages are formed in the section. From the middle and late Yanshanian to the present, the tectonic stress field in the area has undergone the transformation from NE near SN EW NN W to multi-stage tectonic stress field. The karst types in the engineering area are mainly karst soil cave (surface karst) and horizontal karst cave (underground karst). In the middle Triassic (T2n2) limestone distribution area, karst soil cave is located along the structural ridge line in the reservoir area. The joints and fissures are distributed in three bands near SN-NW, and are concentrated in development, and most of them are beaded. On the developmental strength, the cross forceps exit of F2 and F4 faults is the strongest in the composite zone of the hot cashmere back inclined axis, the hot velvet chichang fault (F1) and the hot pile anticline. Horizontal caverns are mainly developed along transverse or longitudinal joints. By using finite element method and ANSYS software, the three-dimensional numerical simulation shows that the horizontal karst caverns all produce certain deformation and displacement under the condition of filling, which is mainly due to the strong development of karst in the area, which makes the bedrock face undulating. The uneven thickness of the overlying soil caused uneven settlement of the foundation in the reservoir area. Under the action of engineering, there is the possibility of collapsing in local areas, which may cause leakage. In the process of engineering construction and operation, it is necessary to take into account this karst geological hazard and take necessary measures to prevent and cure it.
【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】：P642.25
本文编号：2405719
[Abstract]:The reservoir area of the tailings of Plang Copper Mine is located at the edge of the world natural heritage site of the Sanjiang parallel flow, and the geotectonic position belongs to the middle arc of the southern part of the Yidun Arc in the Tethys tectonic domain of Sanjiang River. The geological structure of the reservoir area is complex. The soluble rock (carbonate rock) accounts for more than 80% of the total area of the reservoir. In the process of engineering investigation, the most prominent engineering geological problem in the proposed project area is karst. The stability of the tailing reservoir foundation and the leakage of the tailings reservoir are caused by the strong karst. Therefore, it is necessary and important to study the characteristics and laws of karst development in reservoir area, control factors, especially the controlling effect of geological structure on karst and its influence on engineering construction. So as to provide a reliable geological basis for the construction of tailings reservoir. On the basis of the basic geological and hydrological engineering geological survey and engineering investigation in the field, combined with geophysical methods, this paper studies the regional geological background, geological structural characteristics, soluble rock distribution characteristics, karst development characteristics and laws in the reservoir area. The geological structure is the main controlling factor of karst development in the proposed tailings reservoir area and its surrounding area. By using finite element method and ANSYS software, the three-dimensional numerical simulation analysis of tectonic-karst in reservoir area under the condition of filling is carried out, and the mechanics and deformation of karst cave are studied, and the influence of karst development on engineering construction is analyzed. The study shows that the main types of geological structures in the reservoir area are fold structure, fault structure and joint structure, which control the karst development in the engineering area. On the plane, different types of geological structures are composed of flat determinant structural assemblages distributed in the NW-SE direction, and hedge-type structural assemblages are formed in the section. From the middle and late Yanshanian to the present, the tectonic stress field in the area has undergone the transformation from NE near SN EW NN W to multi-stage tectonic stress field. The karst types in the engineering area are mainly karst soil cave (surface karst) and horizontal karst cave (underground karst). In the middle Triassic (T2n2) limestone distribution area, karst soil cave is located along the structural ridge line in the reservoir area. The joints and fissures are distributed in three bands near SN-NW, and are concentrated in development, and most of them are beaded. On the developmental strength, the cross forceps exit of F2 and F4 faults is the strongest in the composite zone of the hot cashmere back inclined axis, the hot velvet chichang fault (F1) and the hot pile anticline. Horizontal caverns are mainly developed along transverse or longitudinal joints. By using finite element method and ANSYS software, the three-dimensional numerical simulation shows that the horizontal karst caverns all produce certain deformation and displacement under the condition of filling, which is mainly due to the strong development of karst in the area, which makes the bedrock face undulating. The uneven thickness of the overlying soil caused uneven settlement of the foundation in the reservoir area. Under the action of engineering, there is the possibility of collapsing in local areas, which may cause leakage. In the process of engineering construction and operation, it is necessary to take into account this karst geological hazard and take necessary measures to prevent and cure it.
【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】：P642.25
【引证文献】
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1 范纯信;孔令广;张单乐;陈洪年;;区域构造应力集中与岩溶发育程度的关系研究[A];加强地质工作促进社会经济和谐发展——2007年华东六省一市地学科技论坛论文集[C];2007年
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