Geological Hazard Development Characteristics And Assessment Of Jiawu Gold Mine In Qinghai

Jiawu Gold Mine is situated in Tongde County of Q inghai province. It is located o in the northeast qinghai-tibet plateau. Because of its special natural geography, topography and climate conditions, prospecting for mineral deposits, mining and other engineering activities, there are a lot of geological disasters such as collapses, landslides and debris flows. Some of them are hidden and they have made serious influence on the development of the further exploration. Therefore, to understand and grasp the development and distribution characteristics of geological disasters in mining areas, carry out the mining area geological hazard risk assessment has important theoretical significance and engineering application value for preventing and controlling the geological hazards, protecting ecological environment and exploring the mining resources safely and reasonably.Based on the geological disaster investigation of the Jiawu Gold Mine, I have used the analytic hierarchy process in combination with the practical situation of the mining area to set up the mathematical model of geological hazard risk assessment which is suitable for the Jiawu Gold Mine and proceed the disaster risk assessment. The main conclusions are as follows:1、The Mining area is the alpine deep cutting area in the terrain of qinghai-tibet plateau. The climate is typically plateau and continental climate, the average annual rainfall is 400-500 mm, concentrated in May to September. They are mainly hard sandy river feldspar-argillaceous fine clastic rock group of Longwuhe group, Middle Triassic, and followed by the Tertiary and Quaternary. Since the Neogene the tectonic activities have been strong there. They are mainly the structural frac tures which trending are nearly EW and NW and secondly folds. The groundwater has a good discharge conditions, weathering in the surface is stronge, rock and soil mediums are loose and fractured, it has a very poor engineering properties. The main human activity in the mining area is mineral exploration and development, and they are mostly gathered in Daxiaoquru Gully, Maridang Gully, Longya Gully and Wasanglongwa Gully, where there are lode.2、The geological disasters in the mining area are mainly collapse, landslides and debris flows. They are gathered in Daxiaoquru Gully, Maridang Gully, Longya Gully and the middle and upper reaches and the slopes which have lode of Wasanglongwa Gully, where the human activities more concentrative. The influencing factors of the mining geological disasters are special topographic and geomorphic conditions, stratum lithology which is unconsolidated under the strong action of tectonic deformation and developmental tectonic activities. The main inducing factors are heavy rain from May to September each year, frequent seismic activity in the plateau area and ongoing engineering activities, such as exploration, including slope cutting and road works, mineral exploration and abandoning wasted slag.3、Making Maridang Gully Debris Flow as an example and based on the analysis of the main influence factors of debris flow development, I have constructed the judgment matrix to calculate and analyze by establishing a hierarc hy structure model. Then I get the result that the risk grade of Maridang Gully Debris Flow is medium. And the main inducing factors are the heavy rain from May to September each year and engineering activities, such as exploration.4、In combination with the practical characteristics of the mining area, I have used the analytic hierarchy process to make the geological hazard risk evaluation of collapses, landslide and debris flow, and make the risk zoning of the Mining area. The results show that Maridang Gully is in the high risk area. Daxiaoquru Gully is in the medium risk area. The alpine regions between Daquru Gully and Maridang Gully and between Maridang Gully and Longya Gully and the region between Longya Gully and Wasanglongwa Gully are in the low risk area.5、Through analyzing the results of geo- hazard assessment in the study area and combined with the status of mining exploration and development, I put forward the corresponding countermeasures and suggestions for preventing and treating the collapses, landslides and debris flows. And I offer corresponding proposals for the engineering accidents such as water seepage and collapses which will be induced in the work progress of making trial trenches and footrills in the mineral exploration.