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| Numerical simulation of gas flow in pores and fissures of coal based on segmentation of DTM threshold |
| WANG Gang1，2，YANG Xinxiang2，ZHANG Xiaoqiang2，LI Wenxin2，SHI Linken2 |
| (1. State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology，Shandong University of Science and Technology，Qingdao，Shandong 266590，China；2. College of Mining and Safety Engineering，Shandong University of Science and Technology，Qingdao，Shandong 266590，China) |
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Abstract In order to obtain the real physical model to characterize the pores and fissures of coal mass and to numerically investigate the internal gas flow，the segmentation of DTM threshold was implemented to segment the CT images. The method of DTM threshold was amended by adding Wiener filter denoising. Its correctness was validated with the three-dimensional reconstruction. The abscissa value corresponding to the maximum value of the minimum on the porosity curve was found to be the optimal threshold. Numerical simulation of gas flow was conducted based on the real physical model of pores and fissures of coal extracted using the DTM threshold segmentation method. Simulation results showed that at the micro-scale(＜100 µm)，the gas flowing pores and fissures agreed with the high speed nonlinear percolation of Forchheimer. The flow velocity grew rapidly in fissures and changed randomly along the direction of flow. The permeability coefficient and non-Darcy coefficient were calculated according to the fitting parameters on average flow velocity.
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| [1] 石祥锋. 岩溶区桩基荷载下隐伏溶洞顶板稳定性研究[D]. 中国科学院研究生院(武汉岩土力学研究所)，2005.(SHI Xiangfeng. Study on the roof stability of concealed karst cave under pile foundation loading in karst areas[D]. The Chinese Academy of Sciences(Wuhan institue of rock and roil mechanics)，2005.(in Chinese))
[2] 闫双斌. 桩基荷载下溶洞顶板稳定性研究[D]. 中南大学，2013. (YAN Shuangbin. Research on the stability of cave roof under pile foundation[D]. Central South University，2013.(in Chinese))
[3] 周翰斌. 岩溶地质覆盖层及溶洞预处理嵌岩钻孔桩施工技术[J]. 第二届全国地下，水下工程技术交流会论文集，2011.(ZHOU Hanbin. Built-in-rock bored pile construction technology of pre- treatment to cover layer and karst cave in karst geology[J]. The Second National Conference Of Underground，Underwater Engineering Technology，2011.(in Chinese) )
[4] 胡朝彬，邓世坤，王宝勋，等. 探地雷达用于人工挖孔桩桩底岩溶探测的应用研究[J]. 地质灾害与环境保护，2009 (2)：74–78.(HU Chaobin，DENG Shikun，WANG Baoxun，et al. Application study of the GPR method in the detection of karsts beneath artificial excavated hole pile[J]. Journal of Geological Hazards and Environment Preservation，2009(2)：74–78.(in Chinese))
[5] 崔志盛，夏才初，赵 凯. 大直径嵌岩桩桩底溶洞探测方法探讨和应用[J]. 西部交通科技，2011(7)：46–50.(CUI Zhisheng，XIA Caichu，ZHAO Kai. Discussion on the method and application of detection method for large diameter rock-socketed pile bottom cave[J]. Western China Communication Science and technology，2011(7)：46–50.(in Chinese))
[6] 葛祖焕，胡纯清，向慧敏，等. 桩端灰岩溶洞探测[J]. 物探与化探，2004，28(1)：85–87.(GE Zuhuan，HU Chunqing，Xiang Huimin，et al. The exploration of limestone karst cave at the end of pile[J]. Geophysical and Geochemical Exploration，2004，28(1)：85–87.(in Chinese))
[7] 练光伟. 钻孔灌注桩桩底溶洞探测技术研究[D]. 重庆交通大学，2012.(LIAN Guangwei. Research on the detection technology of cave on the bottom of the cast-in-place pile[D]. Chongqing Jiaotong University，2012.(in Chinese))
[8] 张 章，孙 涛，刘继东，等. 探地雷达频域分析法在桩底岩溶探测中的应用[J]. 土工基础，2014 (2)：163–166.(ZHANG zhang，SUN tao，LIU jidong，et al Frequency domain analysis of ground penetrating rader in detecting the karst rock cavity under pile tips[J]. Soil Eng.and Foundation，2014(2)：163–166.(in Chinese))
[9] 刘文峰，张振勇. 探地雷达在岩溶地基探测中的应用[J]. 物探与化探，2014(3)：624–628.(LIU Wenfeng，ZHANG Zhenlei. The application of ground-penetrating radar to the karst foundation investigation[J]. Geophysical and Geochemical exploration，2014(3)：624–628.(in Chinese))
[10] 陈剑华. 岩溶强发育地区深桩基础施工关键技术研究[D]. 中南大学，2014.(CHEN jianhua. Research on the construction technology of the deep pile foundation in the strong karst development area[D]. Central South University，2014.(in Chinese))
[11] 赵 杰. 大直径桩桩位岩溶管波探测技术研究[D]. 中国海洋大学，2012.(ZHAO jie.Research of tube wave prospecting karst development under large diameter pile[D]. Ocean University of China，2012.(in Chinese))
[12] GB50021—2009. 岩土工程勘察规范[S]. (GB50021—2009. Code for Investigation of Geotechnical Engineering.(in Chinese))
[13] 王炳和，李宏昌. 声纳技术的应用及其最新进展[J]. 物理，2001，30(08)：491–495.(WANG Binghe，LI HongChang. Application and development of sonar technology[J]. Physicis，2001，30(08)：491–495.(in Chinese))
[14] 钟世航，孙宏志，王 荣，等. 陆地声呐法在探查单个溶洞方面的优势[J]. 物探与化探，2008，31(B10)：111–115.(ZHONG Shihang，SUN Hongzhi，WANG Rong，et al. The superiority of landsonar in karst cave survey[J]. Geophysical and Geochemical Exploration，2008，31(B10)：111–115.(in Chinese))
[15] 田 坦. 声呐技术[M]. 第二版. 哈尔滨市：哈尔滨工程大学出版社，2009.(TIAN Tan. Sonar Technology [M]. Harbin：Harbin Engineering University Press，2009.(in Chinese))
[16] 特尔福德. 应用地球物理[M]. 第二版. 北京市：科学出版社. (2011.W.M.Telford.. Applied Geophysics[M]. Beijing：Science Press，2011.(in Chinese) |
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2016, Vol. 35 
