Abstract: A method for manufacturing, transporting and installing on a building site a prefabricated structure made of reinforced concrete for the replacement of a structure such as a manhole, access chamber, access vault, junction box or other, which is buried in the ground and is part of an underground network such as a sewer, aqueduct, gas, electrical distribution, telecommunications, cable television and the like. In this method, concrete is poured in factory against the external surfaces of an integrated removable handling system, which is used as top part of a mold for manufacturing the prefabricated structure. The handling system is fixed to the prefabricated structure in a removable manner. The handling system remains in place during the subsequent steps of unmoulding, transporting and installing the prefabricated structure to the building site. Finally, once the installation is completed, the handling system is removed from the structure.

Abstract: A method for manufacturing, transporting and installing on a building site a prefabricated structure made of reinforced concrete for the replacement of a structure such as a manhole, access chamber, access vault, junction box or other, which is buried in the ground and is part of an underground network such as a sewer, aqueduct, gas, electrical distribution, telecommunications, cable television and the like. In this method, concrete is poured in factory against the external surfaces of an integrated removable handling system, which is used as top part of a mold for manufacturing the prefabricated structure. The handling system is fixed to the prefabricated structure in a removable manner. The handling system remains in place during the subsequent steps of unmoulding, transporting and installing the prefabricated structure to the building site. Finally, once the installation is completed, the handling system is removed from the structure.

Abstract: Disclosed is a chimney access structure which is particularly well adapted for use in grounds subject to freezing. This structure incorporates chimney provided with an upper end on which is mounted an adaptor provided with a vertical through-hole and with a countersink hole of greater diameter that the through-hole. The countersink hole is preferably frusto-conical and extends coaxially within the through-hole at a given depth from the upper face of the adaptor. This countersink hole defines a sleeve with upper portion of the adaptor which is provided with an inwardly projecting flexible sealing ring. A floating head is slidably mounted into the sleeve. This head has a vertical through-hole coaxial with the one of the adaptor. The floating head also has a lower portion provided with an outer lateral surface whose shape and size are selected to fit into the countersink hole of the adaptor and sealingly slide within the same thanks to the sealing ring.