Experimental study on bearing characteristics of filled piers in coal mine goaf

Authors

ZHU Shibin, Xi'an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi'an 710077, China

Abstract

The high concentration slurry is poured into the goaf to form filled piers. The bearing capacity of the piers to the superstructure are affected by the overlap size. In order to grasp the influence of the overlap size on the bearing capacity of the overlying rock layer, high concentration slurry was prepared which selected cement as the cementing material, standard sand as the aggregate. 3D printing technology was used to make the mold to produce the overlapped round table samples. The uniaxial compression test was carried out. Test results show that, when the top area and height of each single pier are the same, the smaller the accumulation angle is, the greater the ultimate bearing capacity is. The ultimate bearing capacity of overlapped two round table specimens with a stacking angle of 30 ° and a stacking angle of 45 ° is in the range of 2.0 to 3.5 times of the corresponding single round table specimen. After the specimen is hardened, the ultimate bearing capacity of the overlapped pier specimen increases first and then decreases as the overlap size increases. When piers filling are used to control the mined-out area, the spacing between the grouting holes should be reasonably set so that the injected slurry forms overlapping piers in large hollow goaf. The bearing capacity of overlapping pier group is better than that of evenly distributed single piers. When filling the goaf with an accumulation angle of 30° to overlap the piers and the distance between the grouting holes is the value corresponding to the limit overlap size of 38.5%, the overall bearing capacity in the treatment site is the largest. The results of this research will provide a basis for the actual use of high concentration slurry for partial filling and treatment of goaf.

Keywords

large hollow goaf, high concentration slurry, filled pier, overlap, the bearing capacity

DOI

10.3969/j.issn.1001-1986.2020.05.013

Recommended Citation

Z. (2020) "Experimental study on bearing characteristics of filled piers in coal mine goaf," Coal Geology & Exploration: Vol. 48: Iss. 5, Article 14.
DOI: 10.3969/j.issn.1001-1986.2020.05.013
Available at: https://cge.researchcommons.org/journal/vol48/iss5/14

Reference

[1] 张志沛,王红. 注浆法在公路下伏煤矿采空区治理工程中的应用[J]. 煤田地质与勘探,2003,31(6):43-47. ZHANG Zhipei,WANG Hong. Applications and studies about grouting on treating the gob areas of coal mine under highway[J]. Coal Geology & Exploration,2003,31(6):43-47.

[2] 张俊英,李文,杨俊哲,等. 神东矿区房采采空区安全隐患评估与治理技术[J]. 煤炭科学技术,2014,42(10):14-19. ZHANG Junying,LI Wen,YANG Junzhe,et al. Research on hazard assessment and control technology of room and pillar mining method goaf in Shendong mining area[J]. Coal Science and Technology,2014,42(10):14-19.

[3] 童立元,刘松玉,邱钰,等. 高速公路下伏采空区问题国内外研究现状及进展[J]. 岩石力学与工程学报,2004,23(7):1198-1202. TONG Liyuan,LIU Songyu,QIU Yu,et al. Current research state of problems associated with mined-out regions under expressway and future development[J]. Chinese Journal of Rock Mechanics and Engineering,2004,23(7):1198-1202.

[4] 朱宜生,刘松玉,童立元,等. 高速公路下伏富水多层采空区注浆处理技术研究[J]. 防灾减灾工程学报,2003,23(4):37-40. ZHU Yisheng,LIU Songyu,TONG Liyuan,et al. Study on grouting technique for treating multi-layered underground mining openings filled with water under highway[J]. Journal of Disaster Prevention and Mitigation Engineering,2003,23(4):37-40.

[5] 苟德明,田娇,李佳佳,等. 高速公路隧道下伏小煤窑采空区洞内注浆处治技术[J]. 林业工程学报,2018,3(5):142-149. GOU Deming,TIAN Jiao,LI Jiajia,et al. Grouting treatment technology of small coal mine goaf beneath expressway tunnel[J]. Journal of Forestry Engineering,2018,3(5):142-149.

[6] 吴爱祥,王勇,王洪江. 膏体充填技术现状及趋势[J]. 金属矿山,2016(7):1-9. WU Aixiang,WANG Yong,WANG Hongjiang. Status and prospects of the paste backfill technology[J]. Metal Mine,2016(7):1-9.

[7] 邓喀中,谭志祥,张宏贞. 长壁开采老采空区带状注浆设计方法[J]. 煤炭学报,2008,33(2):153-156. DENG Kazhong,TAN Zhixiang,ZHANG Hongzhen. Design method of strip grouting for old long wall mining goaf[J]. Journal of China Coal Society,2008,33(2):153-156.

[8] 张新国,江宁,江兴元,等. 膏体充填开采条带煤柱充填体稳定性监测研究[J]. 煤炭科学技术,2013,41(2):13-15. ZHANG Xinguo,JIANG Ning,JIANG Xingyuan,et al. Study on backfill body stability site monitoring during strip coal pillar backfill mining with pastes[J]. Coal Science and Technology,2013,41(2):13-15.

[9] 王洪江,李辉,吴爱祥,等. 基于全尾砂级配的膏体新定义[J]. 中南大学学报(自然科学版),2014,45(2):557-562. WANG Hongjiang,LI Hui,WU Aixiang,et al. New paste definition based on grading of full tailings[J]. Journal of Central South University(Science and Technology),2014,45(2):557-562.

[10] 刘鹏亮,张华兴,崔锋,等. 风积砂似膏体机械化充填保水采煤技术与实践[J]. 煤炭学报,2017,42(1):118-126. LIU Pengliang,ZHANG Huaxing,CUI Feng,et al. Technology and practice of mechanized backfill mining for water protection with Aeolian sand paste-like[J]. Journal of China Coal Society,2017,42(1):118-126.

[11] 元强,李白云,史才军,等. 混凝土泵送性能的流变学表征及预测综述[J]. 材料导报,2018,32(17):2976-2985. YUAN Qiang,LI Baiyun,SHI Caijun,et al. An overview on the prediction and rheological characterization of pumping concrete[J]. Materials Reports,2018,32(17):2976-2985.

[12] 吴爱祥,王洪江. 金属矿膏体充填理论与技术[M]. 北京:科学出版社,2015. WU Aixiang,WANG Hongjiang. Paste backfill theory and technology of metal mine[M]. Beijing:Science Press,2015.

[13] 陈杰,梁杨芝,王俊,等. 高沙充填材料的输送性能研究[J]. 硅酸盐通报,2020,39(1):194-198. CHEN Jie,LIANG Yangzhi,WANG Jun,et al. Research on transport characteristic of high sand content filling material[J]. Bulletin of the Chinese Ceramic Society,2020,39(1):194-198.

[14] WU Aixiang,WANG Yong,WANG Hongjiang,et al. Coupled effects of cement type and water quality on the properties of cemented paste backfill[J]. International Journal of Mineral Processing,2015,143:65-71.

[15] 吴爱祥,刘晓辉,王洪江,等. 结构流充填料浆管道输送阻力特性[J]. 中南大学学报(自然科学版),2014,45(12):4325-4330. WU Aixiang,LIU Xiaohui,WANG Hongjiang,et al. Resistance characteristics of structure fluid backfilling slurry in pipeline transport[J]. Journal of Central South University(Science and Technology),2014,45(12):4325-4330.

[16] 王勇,吴爱祥,王洪江,等. 从屈服应力角度完善膏体定义[J]. 北京科技大学学报,2014,36(7):855-860. WANG Yong,WU Aixiang,WANG Hongjiang,et al. Further development of paste definition from the viewpoint of yield tress[J]. Journal of University of Science and Technology Beijing,2014,36(7):855-860.

[17] 杨鹏,吴爱祥,王洪江,等. 泵送剂对膏体料浆流动性能作用的微结构模型[J]. 有色金属(矿山部分),2015,67(1):59-64. YANG Peng,WU Aixiang,WANG Hongjiang,et al. Microstructure model of paste slurry rheological properties with pumping admixture[J]. Nonferrous Metals(Mining Section),2015,67(1):59-64.

[18] 张钦礼,刘伟军,王新民,等. 充填膏体流变参数优化预测模型[J]. 中南大学学报(自然科学版),2018,49(1):124-130. ZHANG Qinli,LIU Weijun,WANG Xinmin,et al. Optimal prediction model of backfill paste rheological parameters[J]. Journal of Central South University(Science and Technology),2018,49(1):124-130.

[19] 张小瑞,赵国彦,李地元,等. 磷石膏膏体充填材料强度优化配比试验研究[J]. 矿冶工程,2015,35(4):9-11. ZHANG Xiaorui,ZHAO Guoyan,LI Diyuan,et al. Experimental study on optimization of phosphogypsum plaster mix proportion for backfill strength[J]. Mining and Metallurgical Engineering,2015,35(4):9-11.

[20] 程海勇,吴爱祥,王洪江,等. 高硫膏体强度劣化机理实验研究[J]. 工程科学学报,2017,39(10):1493-1497. CHENG Haiyong,WU Aixiang,WANG Hongjiang,et al. Experimental study on the strength deterioration of sulfidic paste backfill[J]. Chinese Journal of Engineering,2017,39(10):1493-1497.

[21] 朱世彬. 高浓度胶结材料在空洞型采空区中的堆积扩散规律试验研究[J]. 能源与环保,2018,40(8):73-77. ZHU Shibin. Experimental study on accumulation and diffusion laws of high concentration cementitious materials in gobs of large caverns[J]. China Energy and Environmental Protection,2018,40(8):73-77.

[22] 李杰,卢朝辉,张其云. 混凝土随机损伤本构关系-单轴受压分析[J]. 同济大学学报(自然科学版),2003,31(5):505-509. LI Jie,LU Zhaohui,ZHANG Qiyun. Study on stochastic damage constitutive law for concrete material subjected to uniaxial compressive stress[J]. Journal of Tongji University(Natural Science),2003,31(5):505-509.

[23] 周长东,厉春龙. 主动约束混凝土圆柱的损伤演化规律[J]. 长安大学学报(自然科学版),2015,35(5):65-72. ZHOU Changdong,LI Chunlong. Damage evolution of active confined concrete cylinder[J]. Journal of Chang'an University(Natural Science Edition),2015,35(5):65-72.

[24] 朱世彬,王晓东,许刚刚,等. 采空区治理中堆积角对充填墩柱承载力影响试验研究[J/OL]. 煤炭科学技术:1-8[2020-06-21]. http://kns.cnki.net/kcms/detail/11.2402.TD.20200206.1341.009.html. ZHU Shibin,WANG Xiaodong,XU Ganggang,et al. Experimental study on influence of stacking angles on the bearing capacity of filled pier in the treatment of large hollow goaf[J/OL]. Coal Science and Technology:1-8[2020-06-21]. http://kns.cnki.net/kcms/detail/11.2402.TD.20200206.1341.009.html.

[25] 温亮,阎长虹,张政,等. 水泥-粉煤灰-煤渣-吹填粉细砂混合料强度试验[J]. 煤田地质与勘探,2019,47(1):149-154. WEN Liang,YAN Changhong,ZHANG Zheng,et al. Test on the strength of the backfill fine sand mixture composed of cement-fly ash-cinder[J]. Coal Geology & Exploration,201947(1):149-154.

[26] 徐斌,董书宁,徐路路,等. 水泥基注浆材料浆液稳定性及其析水规律试验[J]. 煤田地质与勘探,2019,47(5):24-31. XU Bin,DONG Shuning,XU Lulu,et al. Stability of cement-based grouting slurry and test of its bleeding law[J]. Coal Geology & Exploration,2019,47(5):24-31.