scholarly journals Study on End-wall Slope Stability of Surface Coal Mine under the Condition of Combined Open-pit Mining with Underground Mining

Author(s):  
Peng Hongge ◽  
Cai Qingxiang ◽  
Zhou Wei ◽  
Shu Jisen

With the deepening of surface coal mine, the application of combined surface mining with underground mining is increased now. According to the influence analysis of underground mining on surface coal mine end-wall slope, the thin plate model of mined slope was proposed with distortion and stress distribution of the girder studied. Considering the practice of combined surface mining with underground mining, the modified method was put forward. Based on the roof breaking law of mined slope, the minimum width of protecting coal pillar was elicited. Subsequently this paper took the combined mining practice of Anjialing surface mine as example to study the subsidence law of roof and the influence of underground mining to surface mine slope. The research conclusion indicates that under the condition of combined mining the deformation and subsidence of overlying strata are obvious with a clear lag time, and the ceiling distortion evokes distortion of mined slope, which can be used as the theory sustainment to stabilization of mined slope under combined surface mining with underground mining.

2020 ◽  
Vol 12 (10) ◽  
pp. 1612 ◽  
Author(s):  
Wu Xiao ◽  
Xinyu Deng ◽  
Tingting He ◽  
Wenqi Chen

The development and utilization of mining resources are basic requirements for social and economic development. Both open-pit mining and underground mining have impacts on land, ecology, and the environment. Of these, open-pit mining is considered to have the greatest impact due to the drastic changes wrought on the original landform and the disturbance to vegetation. As awareness of environmental protection has grown, land reclamation has been included in the mining process. In this study, we used the Shengli Coalfield in the eastern steppe region of Inner Mongolia to demonstrate a mining and reclamation monitoring process. We combined the Google Earth Engine platform with time series Landsat images and the LandTrendr algorithm to identify and monitor mining disturbances to grassland and land reclamation in open-pit mining areas of the coalfield between 2003 and 2019. Pixel-based trajectories were used to reconstruct the temporal evolution of vegetation, and sequential Landsat archive data were used to achieve accurate measures of disturbances to vegetation. The results show that: (1) the proposed method can be used to determine the years in which vegetation disturbance and recovery occurred with accuracies of 86.53% and 78.57%, respectively; (2) mining in the Shengli mining area resulted in the conversion of 89.98 km2 of land from grassland, water, etc., to barren earth, and only 23.54 km2 was reclaimed, for a reclamation rate of 26.16%; and (3) the method proposed in this paper can achieve fast, efficient identification of surface mining land disturbances and reclamation, and has the potential to be applied to other similar areas.


2021 ◽  
Vol 303 ◽  
pp. 01029
Author(s):  
Alexander Katsubin ◽  
Victor Martyanov ◽  
Milan Grohol

Information about the geological structure of Kuznetsky coal basin (Kuzbass) allows us to note that coal deposits developed by open-cast method are characterized by complicated conditions and have the following features: large length of deposits at significant depths of occurrence; coal series bedding of different thicknesses (from 1 to 40 m); different dip angles (from 3 to 90º); a significant number of dip and direction disturbances; different thickness of unconsolidated quaternary sediments (from 5 to 40 m); a wide range of strength values of rocks. In addition, there is a thickness irregularity and frequent variability of elements of occurrence of coal seams within the boundaries of a quarry field both in length and depth of mining. From the point of view of open-pit mining, such deposits are complex-structured. The factors listed above have a decisive influence on the choice of technical means, the order of development and the possibility of carrying out surface mining operations. Therefore, there is a need for a systematization of mining and geological conditions for the development of coal deposits, the purpose of which is to ensure a process of evaluation of complex-structured coal deposits for the development of coal-bearing zones by various complexes of equipment.


2016 ◽  
Vol 26 (6) ◽  
pp. 1065-1071 ◽  
Author(s):  
Eugene Ben-Awuah ◽  
Otto Richter ◽  
Tarrant Elkington ◽  
Yashar Pourrahimian

2014 ◽  
Vol 926-930 ◽  
pp. 593-596
Author(s):  
Fang Wang ◽  
Chong Shi ◽  
Kai Hua Chen ◽  
De Jie Li ◽  
Ke Han

The process of open-pit mining can lead to high slopes in iron mines, and natural slopes should be rebuilt by the method of roof fall as the exploitation style turns from open-pit mining to the underground mining. So the slope can be steep, deep and may has the characteristics of collapse. It is difficult to describe the stabilization of the mining slope by a conventional safety factor method. Through the numerical simulation of underground mining process, this paper analyzes the result of distortion stress and rock movement rupture range. Studies have shown that the failure mode is dominated by tensile failure as a pattern of collapse and few is dominated by shear failure. The failure zone is controlled by rock mass parameters and structures. The results can be helpful for the proposition of exploitation program and safety management design.


2020 ◽  
Author(s):  
Zhigang TAO ◽  
keyuan LIU ◽  
Xiaojie YANG ◽  
Jingtao LI ◽  
Peng ZHANG ◽  
...  

Abstract With the depletion of shallow coal resources in China, the depths and scales of mining have increased. For several coal mines, the extraction has changed from open-pit to underground. Due to open-pit and underground mining disturbance, landslide disasters frequently occur at high and steep slopes of open-pit mines. The effective identification of danger zone of slope and accurate determination of corresponding stability is important in the field of geotechnical engineering. Herein, Antaibao open-pit coal mine was employed as the research object. Firstly, as per the composition and structural characteristics of on-site slope rock mass, six typical disaster factors were summarized, while the assignment criteria for discrete and continuous variables were divided according to the landslide body characteristics and spatiotemporal distribution. Thereafter, based on the comprehensive evaluation principle of fuzzy mathematics, high and steep side stability in the multi-factor influence regions was comprehensively evaluated, while the spatial division of the unstable region was determined. Finally, the slope potential slip surface in the unstable zone of the western side was utilized as the calculation model object, and sensitivity analysis of the slope impact factor was conducted using the MSARMA method. Therefore, the earthquake as well as drainage rate (groundwater dynamics) were determined as the sensitivity factors. The numerical simulation of FLAC3D finite difference method was performed to analyze the evolution law of displacement field under natural, seepage, and vibrational conditions of the northwest slope.


2021 ◽  
Vol 280 ◽  
pp. 08001
Author(s):  
Khavalbolot Kyelgyenbai ◽  
Serhii Pysmennyi ◽  
Serhii Chukharev ◽  
Batbolor Purev ◽  
Ijilmaa Jambaa

Erdenet copper-molybdenum deposit is the biggest one in the world and has a significant impact on Mongolian society and economy. Today LIEBHERR-994B hydraulic shovels from Germany, electric shovels including EKG-10 and EKG-15 from Russia operate for the mining works, and dump truck BelAZ - 75130 used for transportation. The causes of shovel downtime are classified as technical, technological, and organizational. During the study period, 41% of the total downtime of the excavator’s park was technical, 45% was technological, and 11% was organizational downtime. For shovels, 7% of technological downtime is due to blasting, and for dump trucks 8.7%. In open-pit mining, blasting is performed on a weekly basis, so the duration of this technological downtime can be considered almost constant. If the time between blasts or period of blasting can be arranged optimally, it will be possible to reduce mining equipment’s downtime due to blasting.


Kakosa South copper deposit is located about 450km northwest of Lusaka between Chingola and Chililabombwe. A comprehensive study of Kakosa South deposit was carried out. In Kakosa area the footwall aquifer rocks comprising sandstone and conglomerates which are thin and as such are not expected to represent major aquifers. Copper mineralisation is found in the upper quartzite and ore-shale. The inclination of the deposit ranges from 250 up to 350 . The hangingwall formations above the upper quartzite are represented by a sequence of dolomite and shale formations. Based on Kakosa geotechnical analysis and rock mass classification, fuzzy TOPSIS approach was employed for the selection of optimal extraction techniques. FTOPSIS approach has precise and specific quantities which are used in order to establish criteria and option weights. Triangular fuzzy numbers were determined to represent semantic variables. The fuzzy numbers for Kakosa South parameters were used as input data in the decision making model and matched against the criteria required for the mining method. Applying FDM model, extraction techniques were ranked. The results indicated that open pit extraction technique was ranked first with 78.90 scores followed by sublevel stoping with 66.88 scores. It is concluded that the Kakosa South copper ore deposit can optimally be extracted by open pit mining up to transition depth and transit from open pit mining to underground mining employing sublevel stoping.


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