Permanent form wall: - comprising: - two skins (2; 3), made of concrete or the like, arranged one (2; 3) opposite the other (3; 2), substantially parallel and spaced apart, so as to define between them an internal volume; - at least one means for connecting these two skins (2; 3) to each other; - at least one rigid means for connecting this wall with another at least similar, juxtaposed wall located in its extension, such a rigid connecting means being provided on at least one of the lateral sides (10, 10') of this wall and being movable in displacement between, on the one hand, a retracted position, in which such a rigid connecting means is at least partially retracted into the internal volume of this wall and, on the other hand, an extended position, in which such a rigid connecting means extends partially inside the inner volume of this wall and partially outside this wall, laterally relative to the lateral edge of this wall, and in the extension of the internal volume of this wall; - means for mounting such a rigid connecting means in a way movable relative to the skins (2; 3) of the wall, between retracted and extended positions; - wherein the means for mounting include, on the one hand, at least one flexible element including a portion that is fixed with respect to the skins (2; 3) of the wall and a portion that is movable with respect to the skins (2; 3) and, on the other hand, at least one means for making such a rigid connecting means and the movable portion firmly integral with such a flexible element. - comprising: - two skins (2; 3), made of concrete or the like, arranged one (2; 3) opposite the other (3; 2), substantially parallel and spaced apart, so as to define between them an internal volume; - at least one means for connecting these two skins (2; 3) to each other; - at least one rigid means for connecting this wall with another at least similar, juxtaposed wall located in its extension, such a rigid connecting means being provided on at least one of the lateral sides (10, 10') of this wall and being movable in displacement between, on the one hand, a retracted position, in which such a rigid connecting means is at least partially retracted into the internal volume of this wall and, on the other hand, an extended position, in which such a rigid connecting means extends partially inside the inner volume of this wall and partially outside this wall, laterally relative to the lateral edge of this wall, and in the extension of the internal volume of this wall; - means for mounting such a rigid connecting means in a way movable relative to the skins (2; 3) of the wall, between retracted and extended positions; - two skins (2; 3), made of concrete or the like, arranged one (2; 3) opposite the other (3; 2), substantially parallel and spaced apart, so as to define between them an internal volume; - at least one means for connecting these two skins (2; 3) to each other; - at least one rigid means for connecting this wall with another at least similar, juxtaposed wall located in its extension, such a rigid connecting means being provided on at least one of the lateral sides (10, 10') of this wall and being movable in displacement between, on the one hand, a retracted position, in which such a rigid connecting means is at least partially retracted into the internal volume of this wall and, on the other hand, an extended position, in which such a rigid connecting means extends partially inside the inner volume of this wall and partially outside this wall, laterally relative to the lateral edge of this wall, and in the extension of the internal volume of this wall; - means for mounting such a rigid connecting means in a way movable relative to the skins (2; 3) of the wall, between retracted and extended positions; - wherein the means for mounting include, on the one hand, at least one flexible element including a portion that is fixed with respect to the skins (2; 3) of the wall and a portion that is movable with respect to the skins (2; 3) and, on the other hand, at least one means for making such a rigid connecting means and the movable portion firmly integral with such a flexible element.