Abstract
According to the mine ground pressure and soil mechanics, the stress under a pillar is proportional to the coal pillar pressure and is in inverse proportion to the vertical depth and the pressure diffusion angle and is spreading along the gravity direction elliptically. In Tashan Coal Mine, by using UDEC, the stress distribution of lower seams was analyzed in three kinds of panels (panel 1, with coal unexcavated on both sides of the panel; panel 2, with coal unexcavated on one side and a pillar on the other side of the panel; and panel 3, with pillars on both sides of the panel). Numerical results show that (1) the area below the gob is a stress-reducing area and this stress is less than half of the original in situ stress and (2) the area below the pillar is a stress-increasing area and this stress is approximately 2.2∼2.8 times the stress of the primary rock, and the diffusion angle of the pillar floor is 18°∼20°. As a result, the roadway in the lower coal seam should be outside of the diffusion angle in order to avoid the influence of the stress-increasing area. The horizontal distance (starting from the edge of the upper pillar) at different depths (starting from the bottom of 2# coal) can be calculated. The roadway at the bottom of 3–5# coal (lower seam) should be set 7∼8 m outside of the upper coal pillar. The length of the panel in the lower coal seam should be approximately shorter than that of the upper panel.
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References
Cassie JW, Cartwright PB, Altounyan R et al. (1999) Coal pillar behaviour from underground stress measurements. 9th International Congress on Rock Mechanics, Paris, 25–28 August 1999, pp: 1347–1354
Clifford B. (2004) The assessment of ground control risk and support integrity in coal mine roadways. PhD thesis. Camborne School of Mines, University of Exeter, 349pp
Du JP, Wang LQ (2003) Special mining methods. China University of Mining and Technology press, Xuzhou
Islam MR, Shinjo R (2009) Numerical simulation of stress distributions and displacements around an entry roadway with igneous intrusion and potential sources of seam gas emission of the Barapukuria coal mine, NW Bangladesh. Int J Coal Geol 78:249–262
Jing L, Hudson JA (2002) Numerical methods in rock mechanics. Int J Rock Mech Mining Sci 39:409–427
Kang QR, Tang JX, Hu H (2011) Stress distribution rule of roadway affected by overhead mining in gently inclined coal seams group. Trans Nonferrous Metals Soc China 21:s529–s535
Luo JA, Wang LG (2014) Floor stress distribution laws under coal pillar in close distance coal seams. Saf Coal Mines 45(2):29–34
Meng XR, Xu CH, Gao ZN, Wang XQ (2010) Stress distribution and damage mechanism of mining floor. J Chin Coal Soc 35(11):1832–1836
Paul S, Chatterjee R (2011) Mapping of cleats and fractures as an indicator of in-situ stress orientation, Jharia Coalfield, India. Int J Coal Geol 88:113–122
Peng WH, Dong ZZ, Li SC (2005) Boundary integral formula of semi-plane elasticity problem and its application. J Chin Univ Mining Technol 34(3):400–404
Qian MG, Shi PW (2003) Mining pressure and strata control. China University of Mining and Technology press, Xuzhou
Qin ZC, Wang TX (2004) Abutment pressure distribution and its transfer law in floor of deep isolated fully-mechanized mining faces using sublevel caving. Chin J Rock Mech Eng 23(7):1127–1131
Suchowerska AM, Merifield RS, Carter JP (2013) Vertical stress changes in multi-seam mining under supercritical longwall panels. Int J Rock Mech Mining Sci 61:306–320
Thin IGT, Pine RJ, Trueman R (1993) Numerical modelling as an aid to the determination of the stress distribution in the goaf due to longwall coal mining. Int J Rock Mech Min Sci Geomech Abstr 30(7):1403–1409
Wagner H (1980) Pillar design in coal mines. J South African Instit Mining Metallurgy 80(1):37–45
Wang LG, Han M, Wang ZS, Ou SB (2013) Stress distribution and damage law of mining floor. J Mining Saf Eng 30(3):317–322
Whittaker (1974) An appraisal of strata control practice. Mining Eng 166(10):9–24
Wilson AH (1983) The stability of underground workings in the soft rocks of the coal measures. Int J Min Eng 1:91–187
Xiao TQ, Bai JB, Xu L, Zhang XB (2011) Characteristics of stress distribution in floor strata and control of roadway stability under coal pillars. Mining Sci Technol (China) 21:243–247
Yavuz H (2004) An estimation method for cover pressure re-establishment distance and pressure distribution in the goaf of longwall coal mines. Int J Rock Mech Mining Sci 41:193–205
Zhai XX (1994) Discussion on influence angle transference of deep mining pillar load in floor strata. Coal Technol Northcast Chin 6:16–18
Zhang HL (2011) Study on stress transmission laws of mining floor and its influence on stability of floor roadway. Doctor’s Thesis, University of China University of Mining and Technology
Zhao CB, Hebblewhite BK, Galvin JM (2000) Analytical solutions for mining induced horizontal stress in floors of coal mining panels. Comput Methods Appl Mech Eng 84:125–142
Zhu SY, Jiang ZQ, Yao P, Xiao WG (2007) Application of analytic method in calculating floor stress of a working face. J Mining Saf Eng 24(2):191–194
Acknowledgments
This project was partially supported by the National Basic Research Program of China (973 Program) (2013CB227903) and the National Natural Science Foundation of China (No. 51004109). Dr. Song Gaofeng made a significant contribution in editing the quality of this paper.
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Xinjie, L., Xiaomeng, L. & Weidong, P. Analysis on the floor stress distribution and roadway position in the close distance coal seams. Arab J Geosci 9, 83 (2016). https://doi.org/10.1007/s12517-015-2035-9
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DOI: https://doi.org/10.1007/s12517-015-2035-9