加载与卸载过程瓦斯抽采钻孔变形特征

发布时间：2018-02-12 17:12

本文关键词： 抽采钻孔采动作用加卸载变形破坏应力变化速率　出处：《煤炭学报》2017年06期 　论文类型：期刊论文

【摘要】：抽采钻孔的稳定性影响到抽采工程效果的好坏。工作面回采过程中,由于支承压力随工作面推进的移动,采动影响范围内的抽采钻孔受到加载、卸载应力的作用。为得到加卸载条件下抽采钻孔变形及破坏规律,采用数值模拟的方法对不同应力变化速率下钻孔的破坏进行了计算,共设计10种计算方案,得到了不同加卸载应力变化速率下的钻孔塑性区分布范围及孔壁位移曲线。同时依据数值计算得到的卸载应力变化速率与孔壁变形相互关系,建立了考虑卸载应力变化速率的钻孔周边切应力计算模型。研究结果表明:加载过程中,加载速率对钻孔周边的破坏范围及孔壁位移不产生影响;卸载过程中,钻孔周边破坏范围与初始卸载应力及卸载速率相关,在进行抽采钻孔布置时需综合考虑钻孔的受载力学特征。
[Abstract]:The stability of the extraction borehole affects the effect of the extraction project. During the mining process, the borehole in the mining affected area is loaded due to the movement of the supporting pressure along with the movement of the working face. The effect of unloading stress. In order to obtain the deformation and failure law of extraction borehole under loading and unloading condition, the failure of borehole under different stress change rate was calculated by numerical simulation method, and 10 calculation schemes were designed. The distribution range of the plastic zone and the displacement curve of the borehole wall are obtained under different loading and unloading stress rates, and the relationship between the unloading stress change rate and the hole wall deformation is obtained according to the numerical calculation. A calculation model of shear stress around the borehole considering the rate of unloading stress change is established. The results show that the loading rate has no effect on the damage range and the displacement of the borehole wall during the loading process, while during the unloading process, the shear stress around the borehole is not affected by the loading rate. The range of failure around the borehole is related to the initial unloading stress and the unloading rate. The mechanical characteristics of the borehole should be taken into account in the layout of the borehole.
【作者单位】：辽宁工程技术大学矿业学院;辽宁工程技术大学力学与工程学院;煤科集团沈阳研究院有限公司;
【基金】：国家重点研发计划资助项目(2016YFC0600704,2016YFC0801404) 国家自然科学基金青年科学基金资助项目(51304111)
【分类号】：TD712.6

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