首页|Determination of the load bearing capacity of pre-stressed expandable props for ground support in underground mines

Determination of the load bearing capacity of pre-stressed expandable props for ground support in underground mines

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This paper aims to determine the load bearing capacity of pre-stressed expandable props with different geometries and load eccentricities for flexible support in underground mining or excavation.It is deduced that the expandable device could have much higher strength(>89 MPa)by laboratory tests,and the load bearing capacity of the expandable prop may depend on the stability of the supporting steel pipe struc-ture.A good agreement was found between the laboratory test and numerical results in terms of the load bearing capacity and the final macro-bending failure pattern for expandable props with heights of 1.5 and 2.7 m,and the theoretical calculation for the strength of traditional steel structures is not directly suitable for the expandable props.Moreover,additional numerical simulations were performed for the expand-able props with different normalized slenderness ratios λn and loading eccentric distances e.The variation of stability coefficient of the expandable prop is in line with the Perry-Robertson equation and its corre-lation coefficients are fitted as a of 0.979 and b of 0.314.For estimating the load bearing capacity of the expandable props,the strength equation for traditional steel structures is improved by introducing a bending magnification factor and by modifying the normalized slenderness ratio to a converted slender-ness ratio.Based on the underground field monitoring for the strength of expandable props with different heights,the empirical eccentric distances were back calculated,and a safety factor is introduced to obtain the designed strength of the expandable prop.In addition,a four-step design procedure is proposed for the expandable prop.

Pillar stabilityLoad bearing capacityExpandable propSlenderness ratioEccentric distance

Kunmeng Li、Kaiyuan Jiang、Yuanhui Li、Xin Wang、Kai Liu、Shuai Xu

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Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China

Key Laboratory of Liaoning Province on Deep Engineering and Intelligent Technology,School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China

China-Canada Centre of Deep Mining Innovation,Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,School of Resources and Civil Engineering,Northeastern Un

Department of Engineering Science,University of Oxford,Oxford OX1 3PJ,United Kingdom

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National Key Research and Development Program of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of China

2022YFC290380452004054522741155187406852074062

2023

矿业科学技术学报(英文版)
中国矿业大学

矿业科学技术学报(英文版)

CSTPCDCSCD北大核心EI
影响因子:1.222
ISSN:2095-2686
年,卷(期):2023.33(8)
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