| 摘要 |
A rock bolt for supporting a rock body comprising an elongated body. The body comprises a contoured wall that defines, at least in part, a lumen passing through the body, an elongated support bar disposed inside the lumen of the body, the support bar having a proximal end and a distal end wherein a flange is disposed at the proximal end and the distal end is configured to have a thrust plate attached thereto and an elongated collar. The elongated collar is disposed, at least in part, inside the lumen of the elongated body and has a lumen, wherein the lumen of the collar slidably receives the support bar and the flange and has a stricture point where a cross-sectional area of the lumen of the collar is reduced for increasing a frictional communication between the support bar and the collar at the stricture point. When a movement of a rock face of the rock body occurs, the rock face bears against the thrust plate causing the support bar and flange to travel through the lumen of the collar thereby permitting the rock bolt to yield and govern the movement, and whereby the stricture point stops the flange travelling through the lumen of the collar past the stricture point. 64 66 7 /78 C' 58 82--T Fig. 2 |
