Video of a twisted yeildable bolt driving into a rock hole

This video shows the process of 23-degree twisted rock bolt (TYB) driving into a hole with 25 mm diameter. TYBs were made of low-alloy steel of 09G2C grade having yield strength 325 MPa, tensile strength 470 MPa, elongation 21% and impact toughness 59 Дж/см3. Uniaxial tensile strength of the rock was 42.3±3.6 MPa and elasticity module 14 GPa. TYB cylindrical rode had diameter 20 mm. The rod had two feathers 3 mm high. The feathers cut the 0.5 grooves. A pneumatic hammer was used to drive the bolt. The hummer had a ring piston, inner channel and a clamp. The bolt was inserted into the channel and fixed with the clamp. The rod bolt was marked with a chalk every 10 cm.

本视频展示了将23度扭转式锚杆（23-degree twisted rock bolt，TYB）打入直径25mm孔内的全过程。该类锚杆由09G2C级低合金钢制成，其屈服强度为325MPa、抗拉强度为470MPa、断后伸长率为21%、冲击韧性为59 Дж/см³。试验所用岩体的单轴抗拉强度为42.3±3.6MPa，弹性模量为14GPa。TYB的圆柱杆体直径为20mm，杆身带有两个高度为3mm的翼肋，该翼肋切削出0.5mm的沟槽。本次试验采用气动锤完成锚杆打入作业，该锤体配备环形活塞、内部通道与夹具。锚杆被插入通道后由夹具固定，杆体每间隔10cm便用粉笔做一次标记。