Centrifugal model test on the effect of rockbolt in sandy ground

Abstract

The effect of rockbolt on the ground stability around a tunnel in sandy and shallow overburden ground was not clarified, and the appropriate length and arrangement of them should be established.
Centrifugal model test using rockbolt was carried out, and the results on the effect of the rockbolt were acquired as follows:
(1) Placing in the part near crown was most effective, and in the part of wall was no effect.
(2) In placing many rockbolt, the length could be shortened to keep crown stable.
(3) In placing long rockbolt, the density of them could be sparse.