Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
  • E02D5/18—Bulkheads or similar walls made solely of concrete in situ
  • E02D5/182—Bulkheads or similar walls made solely of concrete in situ using formworks to separate sections

Definitions

• the invention relates to a method and a device for producing a diaphragm wall of reinforced concrete in the ground.
• the invention relates more precisely to a method in which a vertical excavation is hollowed out by means of an excavation tool, a reinforcement cage capable of reinforcing the concrete of the excavation and a formwork is joined and lowered simultaneously into the excavation suitable for constituting at one end of the excavation a seal between this excavation and the next contiguous excavation, liquid concrete is poured into the excavation and the concrete is allowed to harden, the formwork is eliminated, and these operations are repeated in a joint excavation and so of excavation in excavation.
• the present invention aims to combine the advantages of a technique where the formwork and the reinforcement cage are secured and of a technique where the formwork is a simple non-deformable but destructible tube in situ, without having the drawbacks of these two techniques.
• the tube in place in the excavation is exposed to the pressure of concreting and must be able to withstand this pressure.
• the present invention provides a solution to these two problems by the use of an open bottom tube which is therefore not very sensitive to Archimede's thrust, and by the subsequent filling of this tube with a filling material for it. to withstand the pressure of concreting.
• the process of the invention is therefore characterized in that a non destructible bottom tube destructible by impact is used as formwork, in that the tube in place in the excavation is filled with filling materials to close the bottom of the tube and allow it to withstand the pressure of concreting, and in that the excavation tool is used, during the next contiguous excavation, to destroy the tube by impact.
• the tube will generally have a circular section, but the invention is not limited to such a section, provided that the tube is hollow and not closed.
• the tube is filled with an inexpensive material which is moreover recoverable when the tube is destroyed.
• this filling material consists of sandbags (or another filling material) lowered to the bottom of the tube to close this bottom, followed by loose gravel.
• a tube as formwork is particularly useful in the two critical cases of deep excavation and that of circular diaphragm walls.
• the latter still has one or more of the following features:
• the tube is fixed to the reinforcement cage by destructible ligatures;
• the cage is provided with rollers to facilitate the positioning of the tube relative to the cage;
• -a tube is used consisting of sections of superimposed tubes connected two by two by an inner sleeve;
• -a grooved tube is used at least externally.
• a device for implementing the method of the invention comprises an excavation tool for digging the excavation, a reinforcement cage, at least one formwork, means for securing the cage and the tube and means for placing in place in the excavation the joined tube and cage, characterized in that the formwork is an open bottom tube which is not deformable but destructible by impact and in that the device comprises means for filling the tube after installation in order to allow it to withstand the pressure concreting.
• FIG. 1 is a perspective view of the assembly constituted by the reinforcement cage and a formwork tube which is fixed to it;
• - Figure 2 is a diagram of details in horizontal section of this assembly, showing the detail of the connections between the cage and the tube;
• FIG. 3 is a vertical diagram in the case of a cage consisting of a lower cage and an upper cage partially overlapping, the tube consisting of two superimposed sections coupled by an inner splicing sleeve;
• FIG. 4 is a vertical diagram of a device for the descent into a excavation of a cage + tube assembly in accordance with the invention and
• FIG. 5 is a diagram of the lower end of said assembly in place in the excavation , after closing and filling the lower end of the tube.
• the tube (1) shown in Figure 1 is a tube of hardened synthetic resin, grooved externally.
• the outside diameter of the tube (1) is the nominal thickness of the wall to be molded.
• the operation of placing the tube on the reinforcement cage is carried out once the cage is constructed and before it is placed in the excavation.
• the base of the tube is wedged in such a way that it is positioned in the excavation not far from the bottom of the excavation.
• the foot of the reinforcement cage is located at a minimum distance (1.00 m) from the bottom of the panel.
• another tube, inside the tube fixed to said reinforcement cage is telescoped until it reaches the bottom of the excavation.
• the tube with the reinforcement cage is introduced into the excavation (fig. 5) filled with bentonite (or similar product to maintain the surrounding ground), for example by means of a crane shown diagrammatically in G (fig. 4) to which the cage and the tube are suspended by slings.
• a plug (7) over a height of about 2.00 meters is formed in the tube by means of sandbags introduced into the tube from the top of the tube in order to give the tube a seal against the concrete to come.
• the tube can then be filled gravel (8) to give it resistance to the pressure of concrete (9).
• the materials placed in the tube, namely the sandbags and the gravel, are removed during the excavation operation of the adjacent excavation by the excavation tool.

Landscapes

• Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Paleontology (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Bulkheads Adapted To Foundation Construction (AREA)
• Sewage (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8865467

Family Applications (1)

Country Status (7)

Cited By (1)

Citations (5)

• 2001
  • 2001-07-13 FR FR0109348A patent/FR2827319B1/fr not_active Expired - Fee Related
• 2002
  • 2002-03-04 HK HK02101646A patent/HK1051466A2/xx not_active IP Right Cessation
  • 2002-07-12 PT PT02784868T patent/PT1407085E/pt unknown
  • 2002-07-12 ES ES02784868T patent/ES2322137T3/es not_active Expired - Lifetime
  • 2002-07-12 EP EP02784868A patent/EP1407085B8/de not_active Expired - Lifetime
  • 2002-07-12 DE DE60231505T patent/DE60231505D1/de not_active Expired - Lifetime
  • 2002-07-12 WO PCT/FR2002/002474 patent/WO2003006750A1/fr not_active Application Discontinuation

Patent Citations (5)

Non-Patent Citations (2)

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