利用抗爆模型试验,研究在洞室顶部爆炸作用下锚杆的破坏形式,并对锚杆的破坏机制进行分析.根据锚固洞室破坏模型试验,发现锚杆主要有4种破坏形态:锚杆被压弯、螺帽没脱落,锚杆被剪断,锚杆被压弯和拉断并螺帽脱落,锚杆的垫板被翻转.通过对洞室破坏形态分析,得出产生锚杆4种破坏形态主要是由于顶爆作用下,产生的压力分布不均匀,在洞室两侧拱脚部位产生一条或多条很深的剪切裂缝所致.最后,针对锚杆的破坏形态,从锚杆杆体、螺帽及垫板方面提出改进锚杆抗爆能力措施.%Based on anti-explosion model test, the failure forms and failure mechanism of the anchor bolts are studied. According to the results of the model tests, anchor bolts under top explosion have four kinds of failure forms, which include compression bending failure, shearing failure, compression bending and tensile failure with shedding of screw cap, and turnover of backing plate. Because the pressure stress is disturbed unevenly under top explosion, which leads to product a few shearing cracks in two sides of arch foot, the four kinds of failure forms are produced. In accordance with failure forms of anchor bolts, technologies with enhancing the explosion resisting capacity of anchor bolts are proposed from the aspects of body of anchor bolts, screw cap and backing plate.
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