金属矿山深部开采突水致灾危险源辨识与危险性评价——以滇东北毛坪铅锌矿为例

HAZARD IDENTIFICATION AND RISK ASSESSMENT OF WATER INRUSH IN DEEP MINING OF METAL MINES:A CASE STUDY OF MAOPING LEAD-ZINC MINE IN NORTHEAST YUNNAN,CHINA

金属矿山进入深部开采后,面临着“三高一扰动”的复杂地质采矿条件,极易诱发突水灾害。本文依托滇东北毛坪铅锌矿,基于水文地质结构研究,对其突水致灾危险源进行了系统辨识和突水危险性评价,确定了深部开采过程中的突水致灾危险源管控措施。根据毛坪铅锌矿的地质、构造与水文地质条件,划分了两类水文地质结构类型,即背斜西翼强富水含水层侧向充水-陡倾型与背斜东翼中等含水岩溶顶底板充水-平缓型。从构造发育、含/隔水层、开采扰动3个方面,对毛坪铅锌矿深部开采的突水危险源进行辨识,建立了层次分析评价模型,获得了主要开采中段的突水危险性分区,划分出了安全区、相对安全区、过渡区、相对危险区、危险区。结果表明,矿区倒三角锥型的疏排水中心为突水危险性较小的区域,即安全区;北部为矿区的二叠系栖霞茅口组灰岩岩溶裂隙强富水含水层是矿区的突水危险性最大的区域,即危险区。从490 m和310 m中段的分区可见,危险区和相对危险区呈北东、北西方向的条带状,和主要的导水构造的发育方向一致。此项研究,为矿山建立“探、防、堵、疏、监”五位一体的综合防治水技术体系提供了科学依据。

After it enters deep mining,the metal mine will face the complex geological conditions of“three highs and one disturbance”.The disturbance of ore body mining can easily induce water inrush disasters.In this paper,the systematic hazard identification and risk assessment of water inrush were carried out on the basis of the hydrogeological structure investigation of the Maoping lead-zinc mine in Northeast Yunnan Province.The control measures of water inrush hazard sources were determined in the deep mining process.According to the geological,tectonic and hydrogeological conditions of the Maoping lead-zinc mine,two types of hydrogeological structures were classified,namely,the strongly water-rich aquifer lateral filling water-steep dip type on the west flank of the Shimenkan anticline and the medium Karst aquifer roof-floor filling water-gentle type on the east flank of the Shimenkan anticline.From the three aspects of tectonic development,aquifer/aquiclude and mining disturbance,a detailed analysis of the hazard identification and risk assessment of water inrush in deep mining of the Maoping lead-zinc mine was conducted.An analytic hierarchy process evaluation model was established to obtain the evaluation map of water inrush risk in the main mining level.The five area types of safe,relatively safe,transitional,relatively dangerous and dangerous area were divided.The evaluation results show that the drainage center of the inverted triangular cone of the mine is the area with less risk of water inrush,i.e.,the safe area.The Permian Qixia and Maokou Formation Karst fissure strong water-rich aquifer in the north is the area with the greatest risk of water inrush in the deep mining,i.e.,the dangerous area.The zoning maps of the 490m and 310m levels show that the dangerous area and the relatively dangerous area are striped in a north-east and north-west direction,which is consistent with the development direction of the main hydraulic conductivity structures.This research provides a scientific basis for the establishment of a five-in-one integrated water control key technology system of“exploration,prevention,blocking,dredging and monitoring”in the deep mining of metal mines.