Disclosed herein are a construction structure and method for an underground facility. The construction structure for an underground facility includes: a facility body including a foundation constructed by pouring concrete, and a cover member extending in the front-back direction and having both ends configured to extend downward and be fixed to the top surface of the foundation to form a tunnel-shaped space therebelow; and a soil cover layer formed to cover the facility body with soil. The construction method for an underground facility includes: forming a pit in the ground; constructing a foundation on the bottom surface of the pit; constructing a cover member to cover the top of the foundation; and constructing a soil cover layer by covering the pit with soil to cover the cover member.

Disclosed herein are a construction structure and method for an underground facility. The construction structure for an underground facility includes: a facility body including a foundation constructed by pouring concrete, and a cover member extending in the front-back direction and having both ends configured to extend downward and be fixed to the top surface of the foundation to form a tunnel-shaped space therebelow; and a soil cover layer formed to cover the facility body with soil. The construction method for an underground facility includes: forming a pit in the ground; constructing a foundation on the bottom surface of the pit; constructing a cover member to cover the top of the foundation; and constructing a soil cover layer by covering the pit with soil to cover the cover member.

A fire resistant tunnel expansion joint system for installation between substrates of a tunnel. The system includes a fire protection barrier applied at a predetermined thickness to the substrates and a fire resistant tunnel expansion joint. The tunnel expansion joint includes a core and a fire retardant infused into the core. The core is configured to define a profile to facilitate the compression of the tunnel expansion joint when installed between the substrates. The fire protection barrier and the fire resistant tunnel expansion joint are each capable of withstanding exposure to a temperature of at least about 540° C. or greater for about five minutes.

Below grade fluid containment structures, which may include a foam floor and a foam wall extending upward from the floor, the foam wall being formed from foam panels. A granular material is provided for reducing hydraulic soil pressure against an exterior face of the foam wall that would otherwise be exerted by the soil, if the soil were allowed to be positioned up against the foam, particularly the foam wall. The well-draining granular material may be gravel, crushed stone, or the like, which provides better drainage as compared to the surrounding soil material. The interior face of the foam is coated with an elastomeric abrasion resistant impact resistant polymeric coating that seals the below grade interior space defined between the floor and the wall in a seamless water-tight configuration.

Below grade fluid containment structures, which may include a foam floor and a foam wall extending upward from the floor, the foam wall being formed from foam panels. A granular material is provided for reducing hydraulic soil pressure against an exterior face of the foam wall that would otherwise be exerted by the soil, if the soil were allowed to be positioned up against the foam, particularly the foam wall. The well-draining granular material may be gravel, crushed stone, or the like, which provides better drainage as compared to the surrounding soil material. The interior face of the foam is coated with an elastomeric abrasion resistant impact resistant polymeric coating that seals the below grade interior space defined between the floor and the wall in a seamless water-tight configuration.

A seismic isolation system for underground structures comprises a periodic foundation and periodic arrays of piles in the soil or periodic piles that surround the underground structure. The periodic foundation may be a foundation of periodic materials. The periodic piles can substantially reduce the incoming seismic waves from the lateral direction. The periodic piles may be vertically arranged layers of periodic materials. The combination of the periodic foundation and periodic piles can result in total isolation for the underground structure. This total isolation may be of particular interest for underground facilities, such as underground nuclear power plants and structures with basements.

A seismic isolation system for underground structures comprises a periodic foundation and periodic arrays of piles in the soil or periodic piles that surround the underground structure. The periodic foundation may be a foundation of periodic materials. The periodic piles can substantially reduce the incoming seismic waves from the lateral direction. The periodic piles may be vertically arranged layers of periodic materials. The combination of the periodic foundation and periodic piles can result in total isolation for the underground structure. This total isolation may be of particular interest for underground facilities, such as underground nuclear power plants and structures with basements.

A mortar collar positionable to contain and protect a flowable sealant during curing thereof.

A mortar collar positionable to contain and protect a flowable sealant during curing thereof.

An apparatus for limiting event energy in an underground structure having free space includes: an inner layer configured to envelope and seal an interior volume; an outer layer configured to envelope the inner layer; and, wherein the interior volume includes a volume-occupying material, having a solid material, a semi-solid material, a gaseous material, or any combination of the solid, the semi-solid, and the gaseous material.