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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.
According to the characteristics of ultra-high pillar structure and force, and taking full account of the initial geometric deviation, a simplified model of the compaction bar was established.Based on the elasto-plastic theory, the deflections and internal forces of the ultra-high pillar with initial geometric defects were analyzed. Based on the Kachanov damage theory, the damage process and the buckling time of the ultra-high-pillar are studied. The results show that under the influence of the initial deflection, different degrees of additional deflection occur in the pillar, and the size and initial deflection and pressure ratio And the ultimate pressure of mine pillar), which increases with the increase of initial deflection and pressure ratio.Analysis of engineering examples shows that the damage inoculation time and instability lag time are different from the initial deflection, pressure ratio and compressive strength There is a close relationship between the stress and initial deflection. The damage inoculation time and instability lag time decrease rapidly. The higher the compressive strength is, the greater the instability lag time is, that is, the ore column is more stable.