To place Mine anchor cable Before inserting the anchor cable into the anchor hole, check whether the anchor cable number matches the hole number. After confirming it is correct, use high-pressure air to clean the hole, and then start installing the anchor cable.

     When installing the mine anchor cable, pay attention to the following four points:

     ① Check the position of the positioning grout stopper ring and the grout stopper ring. If damaged, replace according to technical requirements;

     ② Check the position and smoothness of the exhaust pipe;

      ③ The mine anchor cable is inserted into the hole. When the positioning grout stopping ring reaches the hole mouth, stop pushing the grout, and install the grouting pipe and one-way valve;

      ④ After the mine anchor cable is in place, recheck if the exhaust pipe is clear. If it is not clear, pull out the anchor cable, troubleshoot, and then re-insert the cable.

       Grouting for mine anchor cables uses bottom-hole grouting construction, injecting grout from the bottom of the borehole, allowing it to empty, and using a grout position indicator to control the grouting position.

      The grouting machine is used for mine anchor cable holes, and the grouting material is M40 cement mortar. Mortar pouring should be sufficiently dense. After the first grouting is completed and the cement mortar solidifies and shrinks, the hole mouth should be filled with grout.

      Mine Anchor Cable Construction Anchor Beam:

       The anchor beam is a compression component that transfers the concentrated load of the anchor to the rock surface. Additionally, since the rock surface at the hole mouth is usually not perpendicular to the anchor cable axis, the anchor beam can adjust the stress direction on the rock surface. To make the upper surface of the anchor beam perpendicular to the anchor cable axis, thin-walled steel pipes with the same drill bit outer diameter need to be welded perpendicularly to the base plate.

       Mine Anchor Cable Tensioning:

       Mine anchor cable tensioning should be performed after the grouting and anchor beam concrete reach 70% of their designed strength. Before tensioning the anchor cable, the tensioning equipment should be calibrated to avoid stress errors. During calibration, connect the jack, oil pipe, pressure gauge, and high-pressure oil pump, and repeat the test three times on the press using the jack's active output method, take the average value, and draw a curve of the jack output (KN) and pressure (kPa) indicated by the pressure gauge, which will serve as the basis for anchor cable tensioning. The initial starting pressure of domestic pressure gauges is not entirely consistent, so the pressure gauge number used during calibration must be noted on the calibration curve and must not be replaced during use. If the pressure gauge is damaged or the jack is disassembled, it should be recalibrated.

        Mine anchor cable Tensioning should be performed in two steps. The first tensioning should be 70% of the total tensioning force, with an interval of no less than 3-5 days between the two tensionings. To reduce prestress loss, the total tensioning force should include an over-tensioning value. When the free section is in a soil layer, the over-tensioning value should be 15%-25%; when the free section is in a rock layer, the over-tensioning value should be 10%-15%. During tensioning, the stress of the anchor cable elongation should be recorded to verify whether the elongation is consistent with the stress. The tensioning force for each layer is the design tension, increased by 25%, with a 2-5 minute interval between each layer, and a 30-minute interval between layers. To overcome prestress loss caused by factors such as strata creep, re-tensioning should be performed, then locked, excess steel strands cut, and the anchor sealed with concrete.