Influence of coal types on overlying strata movement and deformation in underground coal gasification without shaft and prediction method of surface subsidence

2018 ◽  
Vol 120 ◽  
pp. 302-312 ◽  
Author(s):  
Huaizhan Li ◽  
Guangli Guo ◽  
Nanshan Zheng
Keyword(s):  
Coal Gasification ◽  
Prediction Method ◽  
Surface Subsidence ◽  
Underground Coal Gasification ◽  
Strata Movement ◽  
Movement And Deformation ◽  
Overlying Strata Movement ◽  
Overlying Strata

scholarly journals Study on Overlying Strata Movement and Surface Subsidence of Coal Workfaces with Karst Aquifer Water

Mathematics ◽  
2022 ◽  
Vol 10 (2) ◽  
pp. 169
Author(s):  
Yuliang Wang ◽  
Guiyi Wu ◽  
Yang Liu ◽  
Zhanbo Cheng
Keyword(s):  
Numerical Model ◽  
Water Inrush ◽  
Karst Aquifer ◽  
Theory Model ◽  
Surface Subsidence ◽  
Strata Movement ◽  
Maximum Value ◽  
Wide Range ◽  
Overlying Strata Movement ◽  
Overlying Strata

The overlying strata layers of coal workfaces with karst aquifer water normally causes serious safety problems due to the precipitation, drainage and water inrush, such as a wide range and long term of surface subsidence. In this study, by taking 10,301 working faces of the Daojiao coal mine in Guizhou Province as the engineering background, the numerical model of water-bearing strata with fluid-solid coupling was established by using UDEC to illustrate the laws of overlying strata movement and surface subsidence. A theory model was proposed to calculate the surface settlement caused by the drainage of aquifer based on the principle of effective stress modified by the Biot coefficient αb. The results showed that the corresponding maximum value (0.72 m) and the range of the surface subsidence with the occurrence of karst aquifer water were larger than that of the overlying strata without karst aquifer water (e.g., the maximum value of surface subsidence with 0.1 m). Moreover, the surface subsidence caused by the drainage of aquifer accounted for 17.8% of the total surface subsidence caused by coal mining. According to the field monitoring of surface subsidence in 10,301 working faces, the maximum value was 0.74 m, which was highly consistent with the results of numerical simulation and theoretical analysis. It verified the accuracy and reliability of the numerical model and the theory model in this study.

Research on Overlying Strata Movement and Deformation under the Conditions of Shortwall and Longwall Mining

2011 ◽  
Vol 90-93 ◽  
pp. 1299-1302 ◽  
Author(s):  
Kuo Li ◽  
Yong Bo Zhang
Keyword(s):  
Coal Mining ◽  
Longwall Mining ◽  
Strata Movement ◽  
Damage Level ◽  
Mining Condition ◽  
Movement And Deformation ◽  
Overlying Strata Movement ◽  
Overlying Strata ◽  
Subsidence Curve

We simulate the rock’s movement and defoemation process in the coal mining, and research the overlying strata movement and deformation under the conditions of shortwall and longwall mining. The conclusion of the experiment indicates: with the method of double deck mining, the rock’s damage level in caving layer is more serious, the final subsidence curve presents a tooth geometry. The subsidence curve of fissure and flexure zone is simily with the longwall mining condition.

scholarly journals Subsidence and heat propagation modeling on the underground coal gasification (Case study at Muara Enim Formation, South Sumatera)

2020 ◽  
Vol 23 (2) ◽  
pp. 83-98
Author(s):  
Zulfahmi Zulfahmi ◽  
◽  
Ildrem Syafri ◽  
Abdurrokhim Abdurrokhim ◽  
Ridho Wattimena ◽  
...  
Keyword(s):  
Coal Gasification ◽  
Mechanical Characteristics ◽  
Heat Propagation ◽  
Surface Subsidence ◽  
Underground Coal Gasification ◽  
Propagation Modeling ◽  
External Conditions ◽  
Cap Rock ◽  
Physical And Mechanical Characteristics

One of the important issues to study underground coal gasification (UCG) is the prediction of surface subsidence. Several parameters that influence these conditions are the thickness of cap rock, the physical and mechanical characteristics, the structure condition, the minerals composition of the rock, and external conditions. This study had been carried out simulation and modeling to determine the level of surface subsidence risk and the effect of high temperatures due to the activities. The modeling results show that the thickness of the rock above the UCG coal seam greatly affects the surface subsidence. The depth is more than 200 m and found that the SF value is 1.59 which indicates UCG reactor depth of ≥ 200 m is safe from the risk of subsidence. From the characteristic aspect of the cap rock, the claystone types which not contain kaolinite minerals are more prone to collapse than those of contain kaolinite minerals. From this models, the gasifier at 150 m depth was estimated that there will be a decline of -7.23 m, and the minimum subsidence is at 275 m about 0.1 m. The heat propagation modeling results show that at 50 m the temperature is estimated to be 213- 289°C, but if the thickness of the cap rock is > 200 m depth, the temperature is around 29-28°C.

scholarly journals The Influences of Key Strata Compound Breakage on the Overlying Strata Movement and Strata Pressure Behavior in Fully Mechanized Caving Mining of Shallow and Extremely Thick Seams: A Case Study

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Junmeng Li ◽  
Yanli Huang ◽  
Jixiong Zhang ◽  
Meng Li ◽  
Ming Qiao ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Abutment Pressure ◽  
Simulation Software ◽  
Strata Movement ◽  
Key Strata ◽  
Pressure Behavior ◽  
Ground Pressure ◽  
Working Face ◽  
Overlying Strata Movement ◽  
Overlying Strata

In order to analyze the impact of compound breakage of key strata on overlying strata movement and strata pressure behavior during the fully mechanized caving mining in shallow and extremely thick seams, this paper took the 1322 fully mechanized caving face in Jindi Coal Mine in Xing County as the engineering background. Under the special mining and geological condition mentioned above, UDEC numerical simulation software was applied to research the engineering problems, and results of numerical simulation were verified through the in-site measurement. The research results showed that during the fully mechanized caving mining in shallow and extremely thick seams, the inferior key strata affected by mining movement behaved in the mode of sliding instability and could not form the stable structure of the voussoir beam after breaking and caving. In addition, the main key strata behaved in the mode of rotary instability, and the caving rocks behind the goaf were gradually compacted because of the periodic instability of the main key strata. With the continuous advance of the working face, the abutment pressure of the working face was affected by the compound breakage and periodic instability of both the inferior key strata and the main key strata, and the peaks of the abutment pressure presented small-big-small-big periodical change characteristics. Meanwhile, the risk of rib spalling ahead of the working face presented different levels of acute or slowing trends. The actual measurement results of ground pressure in the working face showed that, in the working process, the first weighting interval of the inferior key strata was about 51 m and its average periodic weighting interval was about 12.6 m, both of which were basically consistent with the results of numerical simulation. The research has great significance in providing theoretical guidance and practical experience for predicting and controlling the ground pressure under the similar mining and geological conditions.

Overlying strata movement law of continuous mining and continuous backfilling cemented-fill mining

2021 ◽  
Vol 80 (20) ◽  
Author(s):  
Hai Lin ◽  
Renshu Yang ◽  
Bin Lu ◽  
Yongliang Li ◽  
Shizheng Fang ◽  
...  
Keyword(s):  
Strata Movement ◽  
Continuous Mining ◽  
Overlying Strata Movement ◽  
Overlying Strata

The Application of Similar Material in the Simulation of Overlying Strata Movement in High Inclined Seam in Dongbaowei Mine

2012 ◽  
Vol 600 ◽  
pp. 194-198 ◽  
Author(s):  
Ming Ming Wen
Keyword(s):  
Coal Seam ◽  
Reference Value ◽  
Geological Condition ◽  
Similar Material ◽  
Strata Movement ◽  
Support Measures ◽  
Working Face ◽  
Overlying Strata Movement ◽  
Similar Material Simulation ◽  
Overlying Strata

Studying on the characteristics of the overlying strata movement in high inclined coal seam, the similar material is applied in the simulation model which was built based on the similar material simulation theory and high inclined seam geological condition of Dongbaowei coal mine. The picture and displacement of overlying strata were obtained from the similar material simulation. As a result, the characteristics of the fracture and movement of overlying strata above the full mechanized working face in high inclined seam. This paper proposes some support measures to improve the safety of the working face. These provide significance theoretical guidance and reference value for other working face in high inclined seam.

scholarly journals Soviet experience of underground coal gasification focusing on surface subsidence

2015 ◽  
Vol 16 (10) ◽  
pp. 839-850 ◽  
Author(s):  
Yury Derbin ◽  
James Walker ◽  
Dariusz Wanatowski ◽  
Alec Marshall
Keyword(s):  
Coal Gasification ◽  
Surface Subsidence ◽  
Underground Coal Gasification ◽  
Soviet Experience
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