Abstract: The invention relates to a grout for making watertight screens which comprises a mixture of water, natural or modified clay, specific blast furnace slag and an activating agent. The invention also relates to a process which makes use of said grout, as well as the use of a specific blast furnace slag for preparing said grout.

Abstract: A drilling machine comprising: a frame; at least one pair of rotary drilling tools having substantially the same axis of rotation; and a support assembly secured to the frame and supporting said pair of tools in rotation, said support assembly presenting an edge facing the cutting face and extending between the tools of said pair of tools, said machine further comprising: means mounted on said support assembly for creating at least one jet of liquid at very high pressure directed towards the cutting face between the action zones of said pair of tools; whereby said jet of liquid at very high pressure breaks up the ridge which forms in the cutting face between the action zones of said pair of rotary tools.

Abstract: The present invention provides a head for injecting a fluid under pressure for breaking up the ground from a borehole and mounted at the end of a string of rods. The body of the drilling head has a bottom wall for mounting a mechanical drilling tool having a feed pipe, at least one injection nozzle, and duct-forming means for connecting the feed pipe with liquid at the inlet of said nozzle, the duct-forming means presenting a mean line having a radius of curvature that varies continuously, the right section of said duct-forming means decreasing regularly over at least half its length from its first end towards its second end. The injection head further comprises at least one pipe for feeding said mechanical tool, said pipe being connected at a first end to said duct-forming means and at a second end to a chamber disposed at the bottom end of said injection head and fitted with a controllable shutter member interposed between said chamber and the pipe for feeding said mechanical tool.

Abstract: The invention provides apparatus for drilling trenches in the ground, the apparatus comprising a frame and a drilling assembly having a horizontal support plate connected to the bottom end of the frame, said plate supporting drilling tools disposed beneath said plate, said trench being filled with a drilling mud. The periphery of said plate has resilient sealing means for co-operating with the walls of the trench so as to provide at least partial sealing between said plate and the walls of the trench, and means for adjusting drilling mud flow rates from the portion of the trench situated above said plate to the portion of the trench situated beneath said plate, and also in the opposite direction.

Abstract: An apparatus for drilling trenches in the ground comprising a main frame having two vertical main faces, a drilling assembly comprising a support disposed at the bottom of said frame, means for causing said drilling assembly to move in vertical translation relative to said main frame by applying a predetermined force to said drilling assembly relative to said main frame, and anchoring means mounted on said main faces for anchoring the main frame to the walls of said trench. The anchoring means comprise a plurality of deformable elements secured to said main faces of the top frame, means for injecting a fluid under pressure into said inflatable elements thereby applying a force between said main frame and the walls of the trench, and means enabling said fluid under pressure to escape from said inflatable elements whereby no force is transmitted between said main frame and the walls of the trench.

Abstract: The invention relates to a cutting tool for digging vertical trenches, the tool comprising: a jib (B); a cutter structure (34; C) suspended from the jib via a cable; a plurality of cutter members (18) disposed on at least one cylindrical surface; a motor assembly (12); power supply means (46) for powering said motor assembly (12). releasable retention means (22; 44) for securing at least a portion of the motor assembly (12) having the cutter members (18) mounted thereto to the bottom end of the structure (34); relative positioning means between the structure (34) and the motor assembly (12); and means for connecting the power supply means (46) to the motor assembly (12); whereby at least a portion of the motor assembly (12) with the cutter members (18) can easily be separated from the structure (34) of the machine.

Abstract: Excavator drum for the production of vertical trenches, comprising a cylindrical shell (22) mounted so as to rotate about its axis of revolution and a plurality of excavating tools (28, 30) mounted on the external face of the said shell.

Abstract: A trailer for a tunnel borer follower train comprises a chassis provided with a plurality of wheels, the chassis at rest presenting a longitudinal axis and a longitudinal plane of symmetry that is vertical. The trailer also comprises at least two tanks mounted on the chassis substantially symmetrically about the longitudinal plane of symmetry of the chassis; apparatus for measuring any tilt of the chassis of the trailer about its longitudinal axis; apparatus for feeding both tanks with liquid; and apparatus for controlling the quantity of liquid in each of the tanks as a function of any measured tilt in such a manner that the quantity of liquid contained in each tank creates a return torque about the longitudinal axis tending to compensate for any tilt of the trailer.

Abstract: The invention provides a bore bit comprising a bottom part having an active bottom face and a top face substantially parallel to the active face; a top part fixed to suspension cables and having a bottom face facing the top face of the bottom part; means for limiting the maximum spacing between the two parts; a cylindrical axial bore passing through both parts; a cylindrical guide penetrating into said bore; and at least one ramp-forming recess and at least one ramp-forming extension for co-operating with said ramp-forming recess in such a manner that movement of the top part towards the bottom part is converted into rotary movement of said top part about the vertical axis, with the end of said rotary movement of the top part imparting rotary movement to the bottom part.

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 a liquid feed 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 a tube. The tube presents a mean line having a first end connected to the bottom end of the liquid feed 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 tube decreases regularly over at least half of its length from its first end to its second end.

Abstract: The invention relates to equipment for drilling a vertical borehole in hard ground, the equipment comprising:

Abstract: The invention relates to a method of boring a hole using a boring system constituted by a simple auger and a dip tube slidably mounted in said auger, said dip tube being provided at its bottom end with a tool.

Abstract: The invention relates to a delayed-setting concrete based on blast furnace slag. The invention further relates to a method of initiating the setting of said concrete.

Abstract: The invention relates to a delayed-setting concrete based on blast furnace slag. The invention further relates to a method of initiating the setting of said concrete.

Abstract: The invention relates to a method of monitoring the diameter of columns made in the ground by jet grouting. In the method, a measuring instrument is provided which is constituted by a tubular element of length substantially equal to the length of the column, said tubular element being fitted with a plurality of emission electrodes for creating an electric field, and with a plurality of measurement electrodes for measuring the resulting potential differences; a reference borehole is made in the ground; an axial borehole is made in the column to be tested; said measuring instrument is inserted in the borehole in said column and voltage measurements are performed at different depths; and said measurements are processed.

Abstract: A machine for making bored piles. The machine includes a vertical guide mast; a rotary drive head that is movable relative to the mast; and an auger having a hollow core and at least one helical blade. An extender tube has a bottom end that is secured to the top end of the auger, the drive head co-operating with the extender tube to rotate both the extender tube and the auger. A dip tube is slidably mounted in the hollow core of the auger and the extender tube, the dip tube having a top end connected to a concrete feed pipe. An annular actuator has a first end secured to the top end of the extender tube and a second end secured to the top end of the dip tube.

Abstract: A rotary displacement piling equipment for boring a hole within the soil includes a rotary displacement bit, driving rod members connected to the bit, a casing surrounding the driving rod member, and a casing adapter having a lower end provided with a cylindrical collar for co-operating with the upper part of the casing for keeping in line the casing with respect to the driving rod member and with an horizontal thrust face for applying a thrust at the upper end of the casing, the driving rod member passing through the casing adapter. The equipment may also include a rotary drive box co-operating with the driving rod member for rotating the driving rod means and provided with connecting member to be connected to the upper end of the casing adapter, and vertical supporting and guiding member for supporting and vertically guiding the rotary drive box.

Abstract: The present invention relates to a method of limiting the release of organic materials into the environment during the making of foundations, according to which a concrete is used which is based on blast furnace slag ground to a fineness of between about 2,500 and 5,000 Blaine. The invention also relates to a concrete which can be used in said method.

Abstract: The invention relates to a trailer for a tunnel borer follower train. The trailer comprises a chassis provided with a plurality of wheels, said chassis at rest presenting a longitudinal axis and a longitudinal plane of symmetry that is vertical. The trailer also comprises at least two tanks mounted on the chassis substantially symmetrically about the longitudinal plane of symmetry of the chassis; means for measuring any tilt of the chassis of the trailer about its longitudinal axis; means for feeding both tanks with liquid; and means for controlling the quantity of liquid in each of the tanks as a function of any measured tilt in such a manner that the quantity of liquid contained in each tank creates a return torque about the longitudinal axis tending to compensate for any tilt of said trailer.

Abstract: The invention relates to a hollow drilling rod for transmitting information, said rod being for placing in a borehole filled with drilling mud.