Abstract: The invention relates to the construction of tunnels.Its subject is a shuttering and shoring wall formed by joining end to end sections (1) which each consists of at least two section parts (2, 3, 4, 5) joined together end to end, the ends facing one another being connected by means of a key (6). Each section part consists of a certain number of elements articulated relative to one another. The key has two lateral insertion surfaces, and the end elements adjacent to the latter are equipped with assembly means compatible with these insertion surfaces.The advantage of the shuttering wall according to the invention is that it consists of elements which can be adapted to any tunnel shape and which can be recovered after use, is easy to handle, makes it possible to transmit longitudinal and transverse forces generated as a result of the advance of the shield of the tunnel-driving machine and the casting of the concrete and does not require the use of a shuttering skin.

Abstract: The compressibility of liquid-saturated soils is increased by mixing the soil with gas-filled, compressible bodies thus changing the dynamic property of the soil to mitigate against pressure changes therein.

Abstract: An apparatus for producing a concrete pile in the ground with an enlarged base, including a tube having a diameter, and an upper and a lower end, a shoe provided at the lower end of the tube and having a larger diameter than the tube so as to form a gap between the tube and the ground, a longitudinal outer casing having a diameter substantially equal to the shoe diameter so as to define a space between the tube and the outer casing, the casing also having a lower end attached to the shoe, and an open upper end so as to allow a free flow of concrete into the space between the tube and the outer casing, a sliding joint provided so as to slidably attach the outer casing to the tube so that a predetermined length of sliding exists between the tube and the outer casing, a pile having a free-falling hammer, the tube, with the outer casing attached, being drivable into the ground by the pile to a depth greater than the length of the outer casing so as to form an opening in the ground and define the gap between the t

Abstract: A method and apparatus for producing in-situ concrete piles with enlarged bases. The method includes the steps of: driving into the ground a tube provided at its lower end with a shoe which is larger than the diameter of the tube, and with an outer casing attached around its lower portion; filling fresh concrete into the gap between the tube and the soil as fast as the opening in the soil is formed; expelling the shoe and a plug of concrete to form the enlarged base; and extracting the tube together with the outer casing.

Abstract: An improved process for the construction of an underground structure, such as a tunnel, as well as the structure thus obtained, are disclosed. A first longitudinal underground passage comprising a series of mechanically resistant pipes is sunk into the soil and a vertical trench is dug beneath the first passage from openings provided in the bottom of the first passage. This trench is filled with concrete and defines a first lateral wall of the structure. Lateral openings in the first passage also are provided, through which another series of mechanically resistant pipes is horizontally driven to form the roof of the structure. A second vertical wall is thereafter formed from a second vertical trench to form a second lateral wall of the structure. Alternatively, first and second longitudinal passages and vertical walls may be constructed simultaneously, and the roof pipes driven from one or both of the longitudinal passages.