Abstract: The invention provides a head for injecting a liquid under pressure from a borehole to break up the soil, said head being mounted at the end of a drill string including liquid feed means for feeding a liquid under pressure. The head comprises a body and an outside wall, the body having at least one injection nozzle mounted therein, the nozzle having an inlet diameter equal to d and presenting an axis x,x′, the body also having duct-forming means. The duct-forming means present a mean line having a first end connected to the bottom end of the liquid feed means and having a second end connected to the nozzle tangentially to the axis x,x′. The mean line is defined by at least one curved portion presenting a radius of curvature that varies continuously. The right section of the duct-forming means decreases regularly over at least half of its length from its first end to its second end.

Abstract: The present invention relates to a drill string fitted with information transmission means. The hollow rods of conductive material have their inside faces covered in an insulating material. The transmission means comprise a first electrical unit having at least a first annular electrode secured to the insulating inside face of the drill string, said electrode being in electrical contact with the mud contained inside the drill string so as to establish a flow of current in the conductive mud; and a second electrical unit disposed in said borehole, close to the top end of the drill string in order at least to receive the information contained in said electrical current.

Abstract: The invention relates to a device for injecting material in the form of a suspension into a cavity. The device comprises an injection tube for injecting the material, the tube having a coupling first end and a second end that is open; a coupling has a cylindrical portion provided with an axial bore having a coupling first end for coupling to the first end of the tube, and a second end, said coupling further comprising a radial stub for coupling to a feed pipe for feeding material in suspension; a vent hose is engaged in the said tube and in the coupling, the hose having a first end projecting from the second end of the tube and a second end that projects from the second end of the coupling; and a sealing piece for establishing sealing between the second end of the coupling and the outside wall of said hose.

Abstract: The invention relates to a device for facilitating the removal of formwork for the end joint of a diaphragm wall panel, said formwork comprising a soleplate having two side edges. The device comprising: two substantially rectangular plates of substantially the same dimensions; spacer means secured to first longitudinal edges of each of said plates to hold them substantially parallel to each other at a spacing h; filler means for filling the volume defined by said plates, the spacer means, and a plane orthogonal to said plates located at a distance d from the second longitudinal edges of the plates; and temporary fixing means for fixing said plates to said soleplate.

Abstract: The invention relates to a cast wall constituted by a succession of panels touching via their end edges and made by casting a binder in contiguous lengths of trench dug in the ground in line with one another, each panel including reinforcement, said wall further including link means between the reinforcements in two contiguous panels. The link means (24, 44) are separate from the reinforcement (22, 42) and comprise an anchor element (24) having a first end fitted with at least one vertical first locking element (28, 30) and a second end engaged in one of said panels (22), and a link element (44) having a first end provided with at least a second locking element (46, 48) suitable for co-operating with the first locking element, and a second end engaged in the other one of said panels (42).