地应力作用下裂隙对锚杆预应力扩散机制的影响

发布时间：2018-03-16 14:39

本文选题：地应力　切入点：裂隙围岩　出处：《科学技术与工程》2017年17期 　论文类型：期刊论文

【摘要】：为深入了解裂隙对锚杆预应力扩散机制的影响,采用将锚杆预应力在裂隙围岩中形成的应力场-锚杆预应力场从围岩应力场中分离出来的方法,系统地研究了地应力作用下裂隙位置、长度和倾角对锚杆预应力扩散机制的影响。研究发现:裂隙长度对锚杆预应力场的影响最显著、次为倾角、再次为位置。裂隙长度存在阈值;随其长度增加,拉、压应力峰值区位置发生转移,拉应力峰值单调增加,压应力峰值则先增大再减小。随裂隙向围岩深部移动,拉、压应力区位置发生互换,拉、压应力峰值总体呈减小趋势。裂隙倾角90°时的锚杆预应力场与30°~75°时的显著不同;随裂隙倾角增大,拉应力峰值按减小→增大→减小的规律变化,压应力峰值先减小再增大。
[Abstract]:In order to deeply understand the influence of cracks on the diffusion mechanism of anchor prestress, the method of separating the stress field formed by bolt prestress in fractured surrounding rock from the stress field of surrounding rock is adopted. The effects of crack position, length and inclination angle on the prestress diffusion mechanism of anchor rod are systematically studied. It is found that the crack length has the most significant effect on the prestressing field of anchor rod, and the second is inclination angle. Once again, there is a threshold of crack length. With the increase of crack length, the position of the peak region of tensile and compressive stress shifts, the peak value of tensile stress increases monotonously, and the peak of compressive stress increases first and then decreases. The position of compressive stress zone is interchangeable, and the tensile stress peak value decreases generally. The prestressing field of anchor rod at 90 掳crack inclination angle is significantly different from that at 30 掳~ 75 掳, and the peak tensile stress decreases with the increase of crack dip angle. 鈫扞ncrease. 鈫扵he peak value of compressive stress decreases first and then increases.
【作者单位】：中国矿业大学深部岩土力学与地下工程国家重点实验室力学与土木工程学院;
【基金】：国家自然科学基金(51374198,51404255)资助
【分类号】：TD353.6

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