1 论文
Investigating different methods used for approximating pillar loads in longwall coal mines 煤矿长壁开采近似矿柱载荷的方法
Abstract: Accurately estimating load distributions and ground responses around underground openings play a significant role in the safety of the operations in underground mines. Adequately designing pillars and other support measures relies highly on the accurate assessment of the loads that will be carried by them, as well as the load-bearing capacities of the supports. There are various methods that can be used to approximate mining-induced loads in stratified rock masses to be used in pillar design. The empirical methods are based on equations derived from large databases of various case studies. They are implemented in government approved design tools and are widely used. There are also analytical and numerical techniques used for more detailed analysis of the induced loads. In this study, two different longwall mines with different panel width-to-depth ratios are analyzed using different methods. The empirical method used in the analysis is the square-decay stress function that uses the abutment angle concept, implemented in pillar design software developed by the National Institute for Occupational Safety and Health (NIOSH). The first numerical method used in the analysis is a displacement-discontinuity (DD) variation of the boundary element method, LaModel, which utilizes the laminated overburden model. The second numerical method used in the analysis is Fast Lagrangian Analysis of Continua (FLAC) with the numerical modeling approach recently developed at West Virginia University which is based on the approach developed by NIOSH. The model includes the 2D slice of a cross-section along the width of the panel with the chain pillar system that also includes the different stratigraphic layers of the overburden. All three methods gave similar results for the shallow mine, both in terms of load percentages and distribution where the variation was more obvious for the deep cover mine. The FLAC3D model was observed to better capture the stress changes observed during the field measurements for both the shallow and deep cover cases. This study allowed us to see the shortcomings of each of these different methods. It was concluded that a numerical model which incorporates the site-specific geology would provide the most precise estimate for complex loading conditions.
Keywords: Abutment loads, Numerical modeling, LaModel, FLAC3D, Longwall coal mines
摘要:准确估计地下开挖周围的荷载分布和地面反应对地下矿山的作业安全起着重要作用。适当地设计矿柱和其他支护措施,高度依赖于对将由其承受的荷载以及支护的承载能力的准确评估。有各种方法可用于近似地层岩体中采矿引起的荷载,以用于矿柱设计。经验方法是基于从各种案例研究的大型数据库中得出的方程。这些方法在政府批准的设计工具中得到实施,并被广泛使用。还有一些分析和数值技术用于对诱导荷载进行更详细的分析。在本研究中,采用不同的方法对两种不同面板宽深比的长壁矿井进行分析。分析中使用的经验方法是采用基台角概念的平方衰减应力函数,在美国国家职业安全与健康研究所(NIOSH)开发的支柱设计软件中实现。分析中使用的第一种数值方法是边界元方法LaModel的位移-不连续(DD)变化,该方法利用层状覆土模型。分析中使用的第二种数值方法是快速拉格朗日连续分析(FLAC),西弗吉尼亚大学最近开发的数值建模方法是基于NIOSH开发的方法。该模型包括沿面板宽度的二维片断面与链柱系统,也包括覆土的不同地层。三种方法对浅层矿区都给出了相似的结果,无论是载荷百分比还是分布,深层覆盖矿区的变化都比较明显。据观察,FLAC3D模型能更好地捕捉到浅部和深部覆盖情况下现场测量中观察到的应力变化。这项研究让我们看到了这些不同方法各自的不足之处。研究的结论是,结合现场具体地质情况的数值模型将为复杂的荷载条件提供最精确的估计。
2 相关文献
Note: '相关文献' 是按照Google的排序算法产生出来的.
[1] Proceedings of the 39th international conference on ground control in mining
[2] An Empirical Method For The Design Of Chain Pillars For Longwall Mining
[3] Effects of Longwall Mining On Real Property Value and the Tax Base of Greene and Washington Counties, Pennsylvania
[4] Calculation of periodic roof weighting in longwall mining
[5] Mining Product: ALPS - Analysis of Longwall Pillar Stability
[6] Analysis and Design Considerations for Superimposed Longwall Gate Roads
[7] Design And Layout Aspects Of Longwall Methods Of Coal Mining
[8] Numerical Model Calibration for Simulating Coal Pillars, Gob and Overburden Response
[9] Optimization of Chain Pillars Design in Longwall Mining Method
3 参考文献
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[2] I.B. Tulu, G. Esterhuizen, K. Mohamed, T. Klemetti Verification of a calibrated longwall model with field measurements Proceedings of 51st US Rock Mechanics/Geomechanics Symposium. San Francisco, CA (2017)
[3] K.A. Heasley, M.M. Sears, I.B. Tulu, C.H. Calderon-Arteaga, L.W. Jimison II Calibrating the LaModel Program for Deep Cover Pillar Retreat Coal Mining Proceedings of the 3rd International Workshop on Coal Pillar Mechanics and Design Morgantown WV (2010), pp. 47-57
[4] K. Heasley Numerical modeling of coal mines with a laminated displacement-discontinuity code Colorado School of Mines, Golden (CO) (1998)
M. Salamon Mechanism of caving in longwall coal mining Proceedings of the 21st U.S. Rock Mechanics Symposium. Denver, CO (1990), pp. 161-168
[5] I.B. Tulu, G. Esterhuizen, D. Gearhart, T. Klemetti, K. Mohamed, D. Su Analysis of global and local stress changes in a longwall gateroad Int J Min Sci Technol (2018), pp. 127-135
[6] D. Gearhart, G. Esterhuizen, I.B. Tulu Changes in stress and displacement caused by longwall panel retreats Proceedings in the 36th International Conference on Ground Control in Mining Morgantown WV (2017), pp. 313-320
[7] T. Klemetti, M. Van Dyke, I.B. Tulu, D. Tuncay, J. Wickline, C. Compton Longwall gateroad yield pillar response and model verification - a case study 53rd US Rock Mechanics/Geomechanics Symposium. New York City (2019)
[8] M.K. Larson, J.K. Whyatt Deep coal longwall panel design for strong strata: the influence of software choice on results G.S. Esterhuizen (Ed.), Proceedings of the International Workshop on Numerical Modeling for Underground Mine Excavation Design (2009)
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