Bolting in Bad Rock

[Mr Mike]

I am looking to replacing some anchors in a shaley type rock down a mine. The face has some really old anchors made from what looks like to be threaded M10 bar, that has been inserted into deeply drilled holes. The location is over a shaft, the wall is covered in calcite flows and the rock is a blocky shale as found around Nenthead area down the mines there.

Can you successfully bolt such rock by say for example, drilling a deep hole in the order of 0.3-0.5m, knocking a threaded bar in to this and placing a standard hanger on the end. The load would be 90-120deg to the bar and wall. Does anyone use such a method for this type of rock?

Would a resin be needed to hold the bar, or would the depth and fact that it would only be loaded at 90-120deg be enough to keep in in most situations?

 

[cavemanmike]

use stainless and yes use resin, drill it in about 30-40 cm. depends how bad the rock is but this is what we use in spar

 

[mikem]

If you don't resin then someone will remove them...

Mike

 

[Balmerfish]

Hi Mr Mike. Which shaft you referring to, please.


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[Mr Mike]

It's Brown's Sump on the Scaleburn XV - connection to Brownley Hill.

 

[Balmerfish]

It's Brown's Sump on the Scaleburn XV - connection to Brownley Hill.

Thank you Mr Mike - i think we used that on Traverse, not 100%. We don't head over that way much.


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[Mr Mike]

Yes you would have, it's the only link.