Safety technical measures for the test of rock anchor bolt pulling force(2)

(Keywords:Test;Mining Rock Anchor Bolt;Split Set Bolt;Friction Rock Bolt)

Ⅳ Detection method

1. Testing method of bolt pull-out force

(1) Operation process

Safety inspection→prepare the workbench→connect the Rock Bolt tension machine→check the oil volume→exhaust gas→operate the oil pump→pulling test→observe the pressure gauge reading→relief pressure→disassemble the tension machine

(2) Operation method

① The bolt pull test work should be coordinated by four people, one person observes the safety of the working environment, one person operates and observes the pressure gauge, and two people coordinate to install the bolt tension machine.

②Connect the drawing machine, screw the extension rod of the rock bolt tension machine to the end of the tested rock bolt, and tighten it, then put on the bushing and jack, make the piston protruding end face outward, and finally tighten the nut.

③The center line of the oil cylinder of the anchor rod pulling machine must coincide with the anchor rod axis.

④ Pull test: Tighten the unloading valve of the hand pump clockwise. Press the lever of the hand pump with even force and not excessive force. When the pressure gauge reading reaches the design specified value, the operation should be stopped. Observe the reading of the pressure gauge, measure the displacement of the rock bolt, and make a record.

⑤ Make a test record, the record should be detailed and clear, including: anchor rod position, pull-out test value, whether the rock bolt is pulled (when the anchor rod has obvious displacement, stop the pressure, record the reading of the anchor rod tension machine at this time, that is, Pull-out test value).

⑥Disassembling the drawing machine: After the inspection, slowly loosen the unloading valve counterclockwise to make the pressure gauge pointer return to the zero position, and the jack pistons are all retracted. Then unload each component from the anchor rod, pack it into a box, and lock it.

2. Detection of Cable Bolt pre-tightening force

(1) Operation process

Safety inspection→prepare the workbench→connect the tensioning machine→operate the oil pump→pulling test→observe the pressure gauge reading→disassemble the tensioning machine

(2) Operation method

① The cable bolt pretension test work should be coordinated by four people, one to observe the safety of the working environment, one to operate and observe the pressure gauge, and two to coordinate the installation of the anchor jack.

②Retract the jack to the initial position, and two experienced workers will install the jack on the tested cable bolt, and ensure that the tensioning cylinder should be kept on the same axis as the steel strand; when the tested cable bolt is relatively high In the high position, a firm and reliable ladder should be used. After the ladder is erected safely and stably and there is a special person to escalate the ladder, the inspector can wear a safety belt to install the inspection instrument on the ladder.

③Turn the reversing and unloading handle of the oil pump to the F0 position, and take out the oil pump, anchor cable tensioner and quick connector plug.

② Connect the two-speed reversing oil pump and the cable bolt tensioner with the high-pressure hose assembly.

③ Insert the connector of the high-pressure hose assembly into the quick connector and insert the U-shaped pin.

④ After checking the reliable connection, connect the air source, move the reversing handle to F1 or F2, observe whether the piston in the cable bolt tensioner cylinder extends, then change the reversing unloading handle to another position, and change the oil pump Retract toward the piston.

⑤ Check for oil leakage or other abnormal phenomena.

⑥ After the check is correct, turn the reversing unloading handle to one side, connect the air source, open the air pressure valve, after pressurizing, the jack can be released after the steel strand is stuck, and the jack is tied to the steel net with 8# iron wire ; It is strictly forbidden to stand within 45° behind the jack to prevent accidental injury; the tension is gradually increased until the pressure reaches 30Mpa.

⑦In the process of tensioning, the operator must watch the pressure gauge reading, and when the pressure gauge reading reaches the designed value, the operation should be stopped. Measure the displacement of the anchor cable and make relevant records.

⑧ Make a test record, the record should be detailed and clear, including: anchor cable position, pre-tightening force test value, whether the anchor cable is pulled (when the anchor cable has obvious displacement, stop the pressure, and record the reading of the tensioner pressure gauge at this time , Which is the test value).

⑨ Disassemble the tensioning machine: After the inspection is completed, retract all the jack pistons and retract them.

⑩After testing, disassemble the stretching machine according to the parts.