The considerations and attentions of self drilling bolt

1) Self drilling anchor bolt has some special advantages than common anchor bolts when forming holes in the gravel layer, sand layer and gravel layer, the casing of self drilling anchor can be omitted, at the same time, the cement slurry is injected into the hole to consolidate the hole wall, thus preventing the collapse of the hole, simplifying the construction procedure, saving the cost, shortening the construction period, and having better economic and social benefits.
2) The construction of self drilling bolt is a highly technical work, and the operation of each process must be meticulous, otherwise, the construction quality of the whole anchor bolt will be affected by the negligence of a certain process. Therefore, the operator must have a high clear division of duties.
3)The test of self drilling bolt should be used before the construction of it, so as to determine the construction parameters and guide the actual construction. If the self drilling bolt of test has the problem of insufficient pulling force, it is necessary to find out the cause and re test the self drilling bolt until it meets the requirements.
4) The choice of drilling machine of self drilling bolt, that is to consider ensuring the quality of drilling, but also easy to hole cuttings discharge.
5) In order to avoid repeated cleaning operations, the hole cleaning method must be selected, it is best to clean the hole once in place.
6) The correct grouting technique must be used and the grouting pressure and grouting times should be controlled well.