分段锚预应力锚杆加固围岩力学分析

发布时间：2018-04-13 06:22

本文选题：受力不均 + 两段锚预应力锚杆　；参考：《岩土力学》2017年10期

【摘要】：基于端锚锚杆支护的优越性和围岩破坏分区及破坏深度逐步向深部发展的规律,针对煤矿深部巷道采用加长或全长锚固锚杆支护时,锚杆的锚固段整体受力不均,抗剪切承载能力低,而端锚锚杆无法适应其大变形缺点的问题,建立了两段锚预应力锚杆支护模型。运用理论计算和数值模拟的手段研究了两段锚预应力锚杆锚固段的受力特征和承载能力,并进行了算例对比分析。结果表明:两段锚分区锚固的支护方式明显改变了加长或全长锚固锚杆锚固段的剪应力曲线变化趋势,使原本呈负指数变化趋势的剪应力曲线变得平缓,提高了锚杆锚固段的剪切承载能力;在相同预紧力作用下,与端锚锚杆相比,明显降低了锚杆锚固段的荷载和剪切应力;在不同预紧力下,两段锚预应力锚杆的两锚固段可分别起到围岩不同变形时期端锚锚杆的支护作用,继续发挥端锚支护的优越性。
[Abstract]:Based on the superiority of end anchor bolt support and the law that the failure zone and failure depth of surrounding rock gradually develop to the deep, when extended or full length anchor bolt support is adopted in deep roadway of coal mine, the overall force of anchor section is uneven.The shear bearing capacity is low, but the end anchor bolt can not adapt to the shortcoming of its large deformation. A two-stage anchor pre-stressed anchor support model is established.By means of theoretical calculation and numerical simulation, the stress characteristics and load-carrying capacity of the two-stage pre-stressed anchor bolt are studied, and a comparative analysis of a numerical example is given.The results show that the shear stress curve of the long or full length Anchorage bolt is obviously changed by the supporting method of the two-stage anchor zone, and the shear stress curve, which is originally a negative exponential trend, becomes flat.Under the same pretightening force, the load and shear stress of the anchoring section are obviously reduced compared with the end anchor bolt, and under different pretightening forces, the shear load and shear stress of the anchoring section are obviously reduced under the same pretension force.The two anchoring sections of two-stage prestressed anchor can play the supporting role of the end anchor in different deformation periods of surrounding rock, and continue to play the superiority of end-anchor support.
【作者单位】：山东科技大学矿山灾害预防控制省部共建国家重点实验室培育基地;山东科技大学矿业与安全工程学院;
【基金】：国家重点研发计划(No.2016YFC0801403) 国家自然科学基金项目(No.51374140,No.51204102)~~
【分类号】：TU476

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