scholarly journals Risk Assessment and Prevention of Surface Subsidence under Buildings by Cemented Paste Filling and Strip Mining Methods: A Case Study

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Sun Qiang ◽  
Zhou Nan ◽  
Song Weijian ◽  
Zhao Xu
Keyword(s):  
Surface Deformation ◽  
Surface Subsidence ◽  
Environmental Benefits ◽  
Strip Mining ◽  
Coal Resources ◽  
Industrial Sites ◽  
Coal Recovery ◽  
Geological Conditions ◽  
Continuous Mining ◽  
Residual Coal

Intensive and continuous mining of coal resources in China implies their gradual exhaustion, especially in the eastern regions. While some mines face closure, others have to extract residual coal resources under buildings, water bodies, and industrial sites. Thus, safe and efficient mining of the residual coal resources requires innovative techniques, which would account for the particular site’s geological conditions. In this study, two schemes of roadway mining with cemented paste backfilling (RMCPB) and strip mining are put forward. After analyzing the type, construction, and protection standard of the buildings, the probability integration method and the prediction model are used to assess the surface subsidence and deformation. The research results show that both schemes can control the surface deformation to a certain extent, but RMCPB combines the advantages of a high coal recovery rate and disposal of gangue waste. According to the surface subsidence predicted and measured data, the RMCPB method can effectively control the surface subsidence, deformation, and buildings’ safety. It also yields significant economic and environmental benefits.

scholarly journals Cemented Backfilling Mining Technology for Gently Inclined Coal Seams Using a Continuous Mining and Continuous Backfilling Method

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Bin Lu ◽  
Yongliang Li ◽  
Shizheng Fang ◽  
Hai Lin ◽  
Ye Zhu
Keyword(s):  
Surface Deformation ◽  
New Technology ◽  
Engineering Application ◽  
Filling Material ◽  
Coal Seams ◽  
Mining Technology ◽  
Coal Resources ◽  
Continuous Mining ◽  
Material Transportation ◽  
Coal Pillars

To improve the efficiency and reduce costs of cemented-fill mining, we propose a continuous mining and continuous backfilling (CMCB) method based on the coal resources at the Yuxing mine in Inner Mongolia, China, and constructed a complete filling material transportation system. The new technology is suitable for cemented-fill mining of gently inclined coal seams. Numerical simulations were performed to investigate the dynamic migration law of surrounding rock stress using CMCB cemented-fill mining technology, and similar simulations were conducted to analyze the movement characteristics of the coal overburden. The results show that the coal pillars and filling body alternately bear and support each other during the CMCB process, which resolves the contradiction between mining and filling, achieves parallel mining and filling operations, and improves mining efficiency. The new mining mode exerts minimal disturbance to the overlying rock and effectively controls surface deformation. The engineering application of this technique is promising and provides theoretical guidance and technical support for safe and efficient mining of the same type of coal resources.

scholarly journals Reasonable coal pillar design and remote control mining technology for highwall residual coal resources

2019 ◽  
Vol 6 (4) ◽  
pp. 181817 ◽  
Author(s):  
Fangtian Wang ◽  
Cun Zhang
Keyword(s):  
Remote Control ◽  
Coal Pillar ◽  
Open Pit Mine ◽  
Open Pit ◽  
Recovery Ratio ◽  
Coal Resources ◽  
The Road ◽  
Highwall Mining ◽  
Geological Conditions ◽  
Residual Coal

Highwall mining (HWM) technology is an efficient method for exploiting residual coal resources in Chinese open-pit coal mines. However, on-site personnel and equipment can be damaged by the instability of the highwall mining residual coal pillars and subsidence of final end-walls. This paper considers the geological conditions of an open-pit mine in Shendong Coal Field (China) in order to prevent overlying rock fall accidents; the Mark-Bieniawski formula and the FLAC3D numerical simulation are used to analyse reasonable coal pillar widths outside and under the road, which were determined to be 1.7 m and 1.3 m, respectively. Using the EBH132 cantilever excavator for remote control mining, the field experiment shows that the recovery ratio of highwall residual coal resources was over 67%; hence, safety, efficiency and high recovery ratio of highwall mining were achieved for the residual coal resources of an open-pit mine.

scholarly journals Research on Continuous Miner Mining with Backfilling Technology under High Geostress and Complex Conditions

2020 ◽  
Vol 165 ◽  
pp. 03042
Author(s):  
Du Tao
Keyword(s):  
Field Application ◽  
Burial Depth ◽  
Mining Technology ◽  
Coal Resources ◽  
Continuous Miner ◽  
Working Face ◽  
Geological Conditions ◽  
Deformation Speed ◽  
Continuous Mining ◽  
High Geostress

Aiming at the mining seam with large burial depth, strong geostress, large deformation of the roadway, and fast deformation speed, in order to efficiently recover the coal resources at the working face and effectively protect the surface buildings. Based on analyse of the law of the appearance of the underground roadway pressure in the relevant working face, combined with continuous miner mining technology and equipment technical characteristics, this paper proposes to use a combination of continuous miner mining technology and backfilling technology to mine under high geostress geological conditions. And optimize the mining process parameters according to the field application. The results show that the continuous mining miner with backfilling method can achieve the efficient recovery of coal resources under high geostress and complex conditions.

scholarly journals Geochemical Risks of Diamond Mining in Siberia

2020 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Yana Legostaeva ◽  
Anna Gololobova ◽  
Vladimir Popov
Keyword(s):  
Chemical Elements ◽  
Particle Size Analysis ◽  
Emission Spectrometry ◽  
Size Analysis ◽  
Spectrophotometric Methods ◽  
Industrial Sites ◽  
Diamond Mining ◽  
Mobile Forms ◽  
Geological Conditions ◽  
Processing Plants

Geochemical risk is caused by the release of hazardous chemicals to the earth surface. Primary diamond deposits are located in difficult mining and geological conditions. They represent natural geochemical anomalies associated with the mineral composition of rocks and groundwater, which contain a number of impurity elements with high toxic properties (Tl, Di, As, Cd, Hg), and increased concentrations of heavy metals (Cu, Zn, Pb, Ti, V and others). The paper presents the physical-geographical and mining-geological conditions of the diamondiferous region, where three large mining and processing divisions operate: Udachninsky, Aikhalsky and Nyurbinsky. pH, organic matter (humus), total nitrogen, and physical clay were identified in the study samples, by using potentiometric, photoelectric colorimetric, spectrophotometric methods, and pipette method for particle size analysis. Gross and mobile forms of trace elements were determined by atomic absorption and emission spectrometry. The groups of elements were identified that determined the natural and man-made anomalies. The accumulation of Cr, Ni, and Co determines the influence of kimberlite magmatism in general. Cu, Sr, and Li are accumulated in the soils of the Daldyn-Alakit diamond-bearing region. Increased concentrations of Mn and Cu are typical in the soils of the Sredne-Markhinsky diamond-bearing region. An assessment of the ecological and geochemical state of the study areas was carried out according to the indicator of total pollution (Zc), which is the sum of the excess of the concentration coefficients of chemical elements accumulating in anomalies. Areas of pollution and zones of the greatest risk are localized, which occupy up to 75% of the total area of industrial sites. They confined to quarry-dump complexes and to areas of impact of tailing dumps of processing plants.

scholarly journals Study on the Rheological Failure Mechanism of Weakly Cemented Soft Rock Roadway during the Mining of Close-Distance Coal Seams: A Case Study

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Wenkai Ru ◽  
Shanchao Hu ◽  
Jianguo Ning ◽  
Jun Wang ◽  
Qingheng Gu ◽  
...  
Keyword(s):  
Coal Seam ◽  
Failure Mechanism ◽  
Coal Pillar ◽  
Soft Rock ◽  
Western China ◽  
Creep Failure ◽  
Mining Areas ◽  
Geological Conditions ◽  
Residual Coal ◽  
Close Distance

During the mining of the shallow-buried and close-distance multiple coal seam, the rheological failure of the surrounding weakly cemented soft rock of the roadway in the lower coal seam under the concentrated stress is very rare. However, the stress on the roof of the upper coal seam is transmitted down through the residual pillar, resulting in this situation. Taking the Gaojialiang coal mine which is located in the mining areas of western China as the research object, the failure mechanism of the roadway roof under the residual coal pillar in the shallow-buried and close-distance multiple seam is studied in combination with field monitoring and numerical simulation. Furthermore, suggestions on the roadway support under such geological conditions are proposed. The results show that the residual coal pillar in the working face of the lower coal seam gradually collapses during the mining of the shallow-buried and close-distance multiple coal seam. The concentrated stress transferred by the coal pillar increases further, which makes the roof stress of the lower coal seam roadway to increase continuously. In addition, the stress of the roadway roof also increases further due to the rotation of the broken rock above the goaf, and the peek region of stress moves to the nongoaf area. Combining the heavy concentrated stress and weakly cemented property, the shallow-buried surrounding rock shows rheological behavior and failure. Therefore, we must pay more attention on the creep failure of the roadway roof under the action of the residual coal pillar even in the shallow-buried coal seam.

New Technology of Surface Subsidence Control and Environmental Protection Research in Coal Mining Region

2014 ◽  
Vol 675-677 ◽  
pp. 1385-1394
Author(s):  
Cheng Rong Jiang ◽  
Liu Yang ◽  
Hao Xie ◽  
Hua Yi Huang ◽  
De Ke Sun
Keyword(s):  
Coal Mining ◽  
New Technology ◽  
Mining Area ◽  
Industrial Test ◽  
Surface Subsidence ◽  
High Concentration ◽  
Geological Conditions ◽  
Surface Subsidence Control ◽  
Fissure Water ◽  
Overlying Strata

In combination with the geological conditions of Tie'er mining area in Tangshan coal mining, this paper not only analyzes the evolution of overlying strata structure in stope and the development law of overlying strata separation, also proposes a new continuous grouting technology with large flow and high concentration slurry. The industrial test showed that, when the grout-mining ratio of the whole mining area is 25.3%, the reducing subsidence ratio is 51.5%, the effect of reducing the surface subsidence is good. According to the chemical analysis of water quality ingredients of slurry, the test result showed, heavy metals contents in fly-ash slurry water do not exceed the standard, which has no bad effect on the fissure water in the bedrock.

Numerical Simulation on the Surface Subsidence Effect during Shield Tunneling Construction

2011 ◽  
Vol 299-300 ◽  
pp. 110-113
Author(s):  
Hai Xia Sun ◽  
Hai Yu Wu ◽  
Si Li Chen
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Surface Deformation ◽  
Influence Factors ◽  
Surface Subsidence ◽  
Shield Tunnel ◽  
Shield Tunneling ◽  
Finite Element Program ◽  
Element Program ◽  
Numerical Simulation Methods

Against the background of shenyang subway shield tunnel construction, the method of numerical simulation methods are used to analyze the factors of surface subsidence caused by shield construction comprehensively, and the universal finite element program ABAQUS is used to establish mechanical model depended on comprehensive consideration the influence factors of soil warehouses pressure, seepage and groundwater. A dynamic finite element simulation of shield advance process and conclude the surface deformation rule of soil are studied.

Analysis and Control of Layer Deformation Induced by the Densely Arranged Large Diameter Underground Steel Tubes Jacking with NTR Method

2015 ◽  
Vol 744-746 ◽  
pp. 1010-1014
Author(s):  
Chun Fu Jin ◽  
Peng Niu ◽  
Yong Sheng Zhao ◽  
Xuan Wang
Keyword(s):  
Surface Deformation ◽  
Large Diameter ◽  
Influence Factors ◽  
Surface Subsidence ◽  
The Finite Element Method ◽  
Steel Tubes ◽  
Steel Pipes ◽  
Pipe Jacking ◽  
And Control ◽  
Layer Deformation

Combined with the finite element method (FEM) and the field data of Shenyang Metro NTR engineering for pipe jacking process, the variation of surface deformation and influence factors of NTR construction are systematically analyzed. The result is shown that the curves of the lateral surface subsidence produced by pipe jacking process are accord with the normal distribution curves put forward by Peck .When the top steel pipes are jacked , the surface subsidence develops rapidly and the rate of deformation is larger. In addition , grouting behind the wall and the sequence of the pipe jacking all have a greater impact on the deformation of the layer.

scholarly journals Experimental Investigation on the Law of Grout Diffusion in Fractured Porous Rock Mass and Its Application

Processes ◽  
2018 ◽  
Vol 6 (10) ◽  
pp. 191 ◽  
Author(s):  
Donghai Jiang ◽  
Xianzhen Cheng ◽  
Hengjie Luan ◽  
Tongxu Wang ◽  
Mingguang Zhang ◽  
...  
Keyword(s):  
Rock Mass ◽  
Permeability Coefficient ◽  
Pressure Coefficient ◽  
Porous Rock ◽  
Cement Ratio ◽  
Coal Resources ◽  
Water Cement Ratio ◽  
Grouting Pressure ◽  
Study Results ◽  
Residual Coal

Because of the limitation of mining techniques and economic conditions, large amounts of residual coal resources have been left in underground coal mines around the world. Currently, with mining technology gradually developing, residual coal can possibly be remined. However, when residual coal is remined, caving areas might form, which can seriously affect the safety of coal mining. Hence, grouting technology is put forward as one of the most effective technologies to solve this problem. To study the grouting diffusion in fractured rock mass, this paper developed a visualization platform of grouting diffusion and a three-dimensional grouting experimental system that can monitor the grout diffusion range, diffusion time and grout pressure; then, a grouting experiment is conducted based on this system. After that, the pattern of the grouting pressure variation, grout flow and grout diffusion surface are analyzed. The relationship among some factors, such as the grouting diffusion radius, compressive strength of the grouted gravel, porosity, water-cement ratio, grouting pressure, grouting time, permeability coefficient and level of grout, is quantitatively analyzed by using MATLAB. The study results show that the flow pattern of the grout in fractured porous rock mass has a parabolic shape from the grouting hole to the bottom. The lower the level is, the larger the diffusion range of the grout is. The grouting pressure has the greatest influence on the grouting diffusion radius, followed by the grouting horizon and water-cement ratio. The grouting permeability coefficient has the least influence on the grouting diffusion radius. The grout water-cement ratio has the greatest influence on the strength of the grouted gravel, followed by the grouting permeability. The grouting pressure coefficient has the least amount of influence on the grouting diffusion radius. According to the results, the grouting parameters are designed, and a layered progressive grouting method is proposed. Finally, borehole observation and a core mechanical property test are conducted to verify the application effect. This grouting technology can contribute to the redevelopment and efficient utilization of wasted underground coal resources.

scholarly journals The Stability of Gob-Side Entry Retaining in a High-Gas-Risk Mine

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Junwen Zhang ◽  
Yulin Li
Keyword(s):  
Coal Mines ◽  
Surrounding Rock ◽  
Shanxi Province ◽  
Engineering Practice ◽  
Efficient Production ◽  
Coal Recovery ◽  
Working Face ◽  
Geological Conditions ◽  
The Stability ◽  
Strengthening Technique

There are series of problems faced by most of the coal mines in China, ranging from low-coal recovery rate and strained replacement of working faces to gas accumulation in the upper corner of coalfaces. Based on the gob-side entry retaining at the No. 18205 working face in a coal mine in Shanxi Province, theoretical analysis, numerical simulation, and engineering practice were comprehensively used to study the mechanical characteristics of the influence of the width of the filling body beside the roadway and the stability of surrounding rock in a high-gas-risk mine. The rational width of the filling body beside the roadway was determined, and a concrete roadway-side support with a headed reinforcement-integrated strengthening technique was proposed, which have been applied in engineering practice. The stability of the filling body beside the roadway is mainly influenced by the movement of the overlying rock strata, and the stability of the surrounding rock can be improved effectively by rationally determining the width of the filling body beside the roadway. When the width of the roadway-side filling body is 2.5 m, the surrounding rock convergence of the gob-side entry retaining is relatively small at only 5% of the convergence ratio. It has been shown that the figure for roof separation is relatively low, and strata behaviors are relatively alleviated and gas density do not exceed the limit, which are the best results of gob-side entry retaining. The results of this research can provide theoretical guidance for excavation of coal mines with similar geological conditions and have some referential significance to safety and efficient production in coal mines.

Sign in / Sign up

Export Citation Format

Share Document