Study on Failure of Soft Overburden of Fully Mechanized Top Coal Caving

Abstract:

The similar material model experiment takes the NO.S2S9 coal face in DaPing coal mine as a prototype to research the characteristics of movement and failure of the soft overburden under fully mechanized top coal caving conditions. The abutment pressure distribution and periodic weighting, caving span are given by monitoring the stress and strain in the similar material model. The results show that rocks fracture extended from button with the advance of workface. The first caving step distance of main roof is 34m. The periodic caving step distance of main roof is 10m. The internal stress field is 10m and the peak abutment pressure point is 80m far away from the coal wall, while the disturbance range in anterior coal wall is 200m. Some cracks are closed in the later stage. The advance of around 300m is the distance that the water flowing fractured zone’s height reaches the highest value. The biggest height of water- flowing fractured zone is 140m. The soft overburden has strong plastic deformation capability. The synchronism of failure and movement of overburden is strong. The failured overburden is compacted and the cracks keep close with the advance of workface. The simulation experiment provides a reference bases for the application and promotion of thick seam mining technology.

• Periodical: Advanced Materials Research (Volumes 446-449)
• Pages: 2192-2195
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.446-449.2192
• Online since: January 2012
• Authors: Jin Shan Wang, Zhong Chang Wang
• Keywords: Caving Span, Mixture Ratio, Soft Overburden, Water-Flowing Fractured Zone

References

[1] Dingli Zhang, Zuode He, Weijun Dong, et al. Study on key technology of fully mechanized sub level caving mining for special thick and hard coal seam. Chinese Journal of Rock Mechanics and Engineering, Vol. 21 (2002), February, pp.273-279. (In Chinese)

[2] Yaoqing Hu, Yangsheng Zhao, Dong Yang, et al. Study of 3D simulation on breakage for coal floor in mining above aquifer. Chinese Journal of Rock Mechanics and Engineering, Vol. 22 (2003), August, pp.1239-1243. (In Chinese)

[3] Xiangdong Zhang, Xueli Fan. Time and space process of overburden strata movement. Chinese Journal of Rock Mechanics and Engineering, Vol. 21 (2002), January, pp.56-59. (In Chinese)

[4] Baocheng Zuo, Congxin Chen, Caihua Liu, et al. Research on similar material of slope simulation experiment. Rock and Soil Mechanics, Vol.25 (2004), November, pp.1805-1808. (In Chinese)

[5] Jialin Xu, Minggao Qian, Weihong Jin. Study and application of separation distribution and development in the process strata movement. Chinese Journal of Geotechnical Engineering，Vol. 26 (2004), May, pp.632-636. (In Chinese)