Abstract: A device for reinforcing a pylon foundation against being pulled out, said foundation comprising at least one block (10) which is buried in the ground of the site of the foundation and that presents a portion (12) of greatest section in a horizontal plane, the device comprising a slab (20) buried in the ground and disposed around said block (10) between said portion (12) and the surface (T) of the ground, said slab extending beyond the vertical projection of the periphery of said portion (12). The slab (20) may be made from a mixture comprising materials extracted from the site or materials brought in from elsewhere (such as a treated gravel mix) or a mixture of both, together with at least one binder. Advantageously, the total proportion of binder in said mixture lies in the range 3% to 15% by weight. The device is used to compensate for a deficit in resistance to being pulled out presented by an existing shallow foundation for a pylon.

Abstract: Structure intended to prevent a relative angular displacement on either side of an expansion joint (3) separating two parts (1, 2) of an assembly forming a very long beam, such as a bridge deck, in particular made from prestressed concrete, includes a rigid beam (8) arranged longitudinally on either side of the joint and resting on each part via two supports (9, 11, 13; 10, 12, 14) spaced apart longitudinally, so as to transmit a bending moment and/or a shearing force without inhibiting the expansions. At least one support is preferably provided with an adjusting jack (13, 14).

Abstract: Method of constructing a cable-stayed bridge whose deck (1) is composed of wo parallel series of voussoirs connected together by connecting members known as deltas (7) which carry at their top part (8) the anchorage points for the cable stays (12). When they are placed in position the bottom parts (9) of the successive deltas are fastened to rigid filling members (14), and auxiliary prestressing cables (13) are preferably installed which connect the top part (8) of a delta to the bottom part (9) of the following delta (7), said cables being approximately in line with the cable stays.

Abstract: A bridge of the cable-stay type, in particular of a very large span, the deck of which is supported by stays deflected by passing over towers (21). Some of the stays (22) are anchored on the deck at two points of the deck situated on either side of a same tower (21), and the central part of a span between two towers is supported exclusively by other stays (25) which, after having been deflected at the top of a tower, are each anchored in an anchor block (26). The tensile stress to which the central part of the deck is subjected under the effect of these stays (25) directed towards the tops of the two towers situated on either side of the span is compensated for by an axial compressive prestress.

Abstract: Bridge comprising a bridge floor, said floor consisting of an upper boom (4) which may form a road section, a lower boom (5) which may be formed by a tubular succession of sections, and diagonal linking girders (6), joining the booms, their axes converging on that of the lower boom. Those elements subjected to high stress are preferably to be provided with individual pretensioning elements. The gussets (15) linking the diagonals with the upper boom carry advantageously the attachment elements of the supporting stay cables (2).