Micropiles are used ether on an inside of a covered perforation or, directly, with the tube for micropile connected to the rotating head of the punch machine. In the latter case the micropile is equipped with a pile shoe to allow the flowing of the drilling liquid and the creation of an annular space sufficient to guarantee the coating of the armour with a 2 or 3 cm of a cement mixture (protection against corrosion).
The 4 blade heads are substituted by tricons when the micropile has to be utilized on a formation of a solid or rocky land.
Another use consists in using the micropile as an ODEX or TUBEX coating with a bottom holed hammer and an eccentric cutter. This method has been utilized with much success, in the execution of gallery threading.
UTILIZATION AND INJECTION
The injection of the micropile happens by the means of a couple of injection pads called M3 and/or M12 inserted in the thickness of the tube. These patented pads, exclusively distributed by R-TUBI S.p.A., work as vales of no return in order to repeatedly inject the land. This ability of reinjection improves the load bearing capacity of the micropile and optimizes the total length of fastening.
The M12 type pad differ from the M3 type for its opening pressure set at around 20 bar to avoid that it will open in the middle of a direct perforation. These pads have to be used together with a double bolt positioned where the couple of pads have to be injected.
On the contrary the M3 type can be injected at the same time by the means of an injection head that can be screwed onto the head element of the micropile. They are of convient use on to lands that don’t require multiple reinjections.
Thanks to their favorable coupling possibility, our micropiles are used in all those works where the limited space of the yard dictates the use of tubes of small dimensions to be assembled between them. Other interesting applications could be the case of difficult access to the yard, where the installation of cumbersome drilling equipment would be impossible and only a light and small drilling equipment is suggested.
In general, our micropiles can be, systematically used in all cases where the traction or compression effort on a surface has to be transmitted to the underground dense layers.