A method for renovating the interior of a hollow structure such as a sewerage pit (1) is described. The method provides an access opening (16) to the hollow structure (1); provides a plurality of material sheets (3) comprising reinforcing fibers and a curable resin composition through the access opening (16) and against a wall (11a, 11b) of the hollow structure (1); and provides an inflatable pressure means (4a, 4b) within the hollow structure (1). The pressure means (4a, 4b) are inflated against the wall (11a, 11b). A curing means (6) is then provided within the hollow structure (1) for curing the resin composition; and the resin composition is cured to harden the material sheets and provide a renovated interior of the hollow structure (1).

A manhole assembly including a base, riser, and cap. The base having an upper surface forming a bench, a bottom surface, and a radially outward surface with penetrations there through; and a radial spigot in the radially outward upper edge of the base. The base having a corrosive-resistant layer covering the channels, bench, and radial spigot. Also disclosed is a riser comprised of a corrosive-resistant polymer pipe having a radially outward surface, an inner surface and a bottom surface in contact with, supported by, and sealed to the radial spigot. The cap having a radial spigot, and access hole; the radial spigot in the radially outward bottom edge of the cap resting upon and sealed to an upper edge of the riser. The radially outward surface of the cap and base are aligned with the radially outward surface of the riser.

A plastic multipurpose component that is suitable as a building block and is filled with filling bodies is used to form a sheet-like assembly from a plurality of components. The multipurpose component has double-walled outer frame parts (2) with an outer frame wall, an inner frame wall and a tread surface connecting them, at least one coupling device (6, 8) for connecting two adjacent components being provided on each of the outer lateral surfaces thereof. Where appropriate inner walls (4) divide the interior of the outer frame (2) formed by outer frame parts into a pattern of cellular lead-throughs (6). Inner bottom support frames (11), and where appropriate, bottom transverse struts on the double-walled outer frame and inner frame serve for stabilizing and supporting at least one filling body introduced in the plastic multipurpose part.

A lift system and method for supporting a structure. The lift system includes a first buoyant sponson tank comprising a sponson tank that extends from a first end to a second end, a mechanical assembly extending from the second end of the sponson tank, the mechanical assembly to transfer a load of a structure disposed on the mechanical assembly to the sponson tank. The sponson tank is configured to be displaced by a volume of fluid that is external to the tank and the tank provides a predetermined buoyant force against the structure to cause the structure to be displaced vertically.

A riser section having a generally tapered, e.g., frustoconical wall, the riser section having a first connector assembly at one end of the riser section and a second connector assembly at the other end of the riser section.

A safety grating has an arch shape cross section and is useful within a riser having a frusto-conical shape wall which riser is attached to a septic tank or another structure. The grating comprises a hub and radially extending arms, one or more of which is rotatable relative to the hub length at a hinge joint, to decrease the size of the grating and enable installation of the grating by passing the grating a smaller end opening of a riser.

A lift system and method for supporting a structure. The lift system includes a first buoyant sponson tank comprising a sponson tank that extends from a first end to a second end, a mechanical assembly extending from the second end of the sponson tank, the mechanical assembly to transfer a load of a structure disposed on the mechanical assembly to the sponson tank. The sponson tank is configured to be displaced by a volume of fluid that is external to the tank and the tank provides a predetermined buoyant force against the structure to cause the structure to be displaced vertically.

A pit and an extension, each having flanges extending perpendicular to an axis of the pit and extension. The pit includes holes extending outwardly in the wall of the pit, preferably these holes are located at one end of the pit. Surfaces of the flanges are configured to mate together and clips secure the flanges together to inhibit movement apart of the pit and extension along the axis. In certain embodiments, the extension includes support ribs which may be both interior and exterior and the extension narrows from its flange towards an opposite end thereof.

A riser section having a generally tapered, e.g., frustoconical wall, the riser section having a first connector assembly at one end of the riser section and a second connector assembly at the other end of the riser section.

A system for circulating air inside a manhole vault. The system includes an air-moving device in fluid communication with the manhole vault and configured to circulate the air inside the manhole vault to prevent a concentration of combustible gasses or to enhance cooling therein.