(1) The steel pipe serves as a grouting pipe, so it is processed into a flower pipe. The end of the steel pipe is closed, and the pipe wall is opened with a grouting hole of p8mm~~12mm, 250mm, in a plum-shaped arrangement. In order to make every grouting hole capable of producing pulp, the longer the steel pipe, the smaller the grouting hole should be. The position of the hole can not be too close to the end, because during the grouting process, the grouting is usually stopped when the hole overflows. If the grouting hole is too close to the end, the amount of slurry in other grouting holes is still very high. When there is little or no slurry, slurry has already flowed from the orifice of the steel tube, affecting the quality of grouting.
(2) The barb shall be welded on the outer wall of the steel pipe. On the one hand, it is ensured that the grouting hole will not be plugged by the soil during the steel pipe injection process, and on the other hand, the friction resistance between the steel pipe and the surrounding soil can be increased. Barbs should be firmly welded and cannot be dropped off during pipe penetration.