| 摘要 |
<p>A method of feeding cement into a drill hole for cement bolting of a rock, according to which a feeder pipe (2) is pushed into the hole essentially to the bottom of the hole portion to be filled with cement, cement is fed into the hole beginning from the bottom of the hole portion, and the pipe is displaced outwards in the hole when the cement fills the hole. The feeding of cement is stopped and the pipe is removed when the amount of cement is sufficient to fill the gap between the wall of the hole and the rock bolt to be pushed into the hole. The displacement of the pipe is controlled by means of the filling pressure (TP) caused by the cement fed between the pipe tip and the bottom of the hole portion to ensure that the hole is reliably filled despite possible cracks and crushed zones. An apparatus for carrying out the method comprises a feeder pipe provided with a tip of such a size that the penetration of cement through the gap between the hole and the tip requires a pressure which is higher than a predetermined set value of the cement feed pressure and causes an outwards pushing force on the tip. (Figure 10)</p> |
