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5 Tips for the Drawing Force Test Method of Self Drilling Hollow Anchor Bar

Date: 2015-06-19view:

1)Drilling in the specified position. Adjust the depth of the bolt holes sightly on the basis of the normal depth so as to make theself drilling hollow anchor bar exposed longer and  ensure the installation of the jack.
2)Place the jack and frame over the bolt and attach the test rod and couplings to the bolt. Install the self drilling hollow anchor bar to be tested, and smooth the mouth of the hollow bar with mortar to put the bearing plate.
3)Attach the test nut and test plate over the test rod on top of the jack. Determine the drawing time according to the type of the self drilling hollow anchor bar and testing purpose.
4)Put the plate in the rear of the self drilling hollow anchor bar, fix the hollow jack to the outer end of anchor bolt and install the displacement measuring equipment and instruments.
5)Test the rock bolt by tensioning the jack to the required test load (usually half of the ultimate strength) but never to exceed the advertised yield strength of the anchor. Adjust the loading of the jack to the required final tension and lock in the final pre-stress load.
This is done by tightening the self drilling hollow anchor bar hex nut with a knocker wrench (through the frame opening) until a slight reduction is noticed on the jack gauge. The full pre-stress load will be transferred to the self drilling hollow anchor bar once the tension in the test jack has been released and test components removed.

 

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