考虑初始缺陷的超高矿柱蠕变分析及失稳滞后时间研究

发布时间：2018-04-28 14:32

  本文选题：初始缺陷 + 超高矿柱　； 参考：《中国矿业大学学报》2017年02期

【摘要】：根据超高矿柱结构及受力特点,并充分考虑初始几何偏差,建立了简化的压杆力学模型.基于弹塑性理论对具有初始几何缺陷的超高矿柱的挠度及内力进行了分析,并基于Kachanov损伤理论,对超高矿柱的损伤过程和失稳时间进行了研究.结果表明,在初始挠度的影响下,矿柱将出现不同程度的附加挠度,大小与初始挠度和压力比(上覆压力与矿柱极限荷载之比)有关,随着初始挠度和压力比的增加而增加.工程实例分析表明,矿柱的损伤孕育时间和失稳滞后时间与初始挠度、压力比及抗压强度有密切的关系,随着压力比和初始挠度增加,损伤孕育时间和失稳滞后时间快速变小,抗压强度越大,失稳滞后时间越大,即矿柱越稳定.
[Abstract]:According to the structure and stress characteristics of ultra-high ore column and taking into account the initial geometric deviation, a simplified mechanical model of compression bar is established. Based on the elastic-plastic theory, the deflection and internal force of ultra-high ore columns with initial geometric defects are analyzed. Based on the Kachanov damage theory, the damage process and instability time of ultra-high ore columns are studied. The results show that under the influence of initial deflection, additional deflection will appear in different degrees, and the size is related to the ratio of initial deflection and pressure (the ratio of overlying pressure to ultimate load of pillar), and increases with the increase of initial deflection and pressure ratio. The analysis of engineering examples shows that the damage incubation time and the unsteady lag time of the pillar are closely related to the initial deflection, pressure ratio and compressive strength. With the increase of the pressure ratio and the initial deflection, the damage incubation time and the unsteady lag time decrease rapidly. The greater the compressive strength, the greater the lag time of instability, that is, the more stable the pillar.
【作者单位】： 北京科技大学土木与资源工程学院金属矿山高效开采与安全教育部重点实验室;
【基金】：国家自然科学基金项目(51374033) 中国博士后科学基金项目(2016M591080)
【分类号】：TD853.391
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本文编号：1815666