A method of forming tunnels(6), and tunnels formed thereby, said tunnels in one embodiment being of a form to carry transport routes (1) such as rail and road transport therealong. The method allows the tunnel to be formed from one or more access points (2) by allowing the tunnel structure (6) to be progressively extended out from the tunnel by advancing deck structures (24) along guide means (20) which are formed as part of a base structure (18). The deck structures (24) can also be used to support excavation equipment (28) and/or act as transport routes for access to the leading edge of the tunnel as it is formed. This greatly reduces the need for separate access and works to be provided adjacent to the tunnel as it is formed and therefore reduces the level of reinstatement works required after the tunnel has been formed.

A method of forming tunnels(6), and tunnels formed thereby, said tunnels in one embodiment being of a form to carry transport routes (1) such as rail and road transport therealong. The method allows the tunnel to be formed from one or more access points (2) by allowing the tunnel structure (6) to be progressively extended out from the tunnel by advancing deck structures (24) along guide means (20) which are formed as part of a base structure (18). The deck structures (24) can also be used to support excavation equipment (28) and/or act as transport routes for access to the leading edge of the tunnel as it is formed. This greatly reduces the need for separate access and works to be provided adjacent to the tunnel as it is formed and therefore reduces the level of reinstatement works required after the tunnel has been formed.

A bridge system is provided that utilizes foundation structures that are formed of the combination of precast and cast-in-place concrete. A method of constructing the combination precast and cast-in-place concrete foundation structures involves receiving at a construction site a precast concrete foundation unit having elongated upright wall members that define a channel therebetween, and multiple upright supports located within the channel; placing the precast concrete foundation unit at a desired use location; delivering concrete into the channel while the precast concrete foundation unit remains at the desired use location; and allowing the concrete to cure-in-place such that the elongated upright wall members are connected to the cured-in-place concrete by reinforcement embedded within both the cured-in-place concrete and the upright wall members. The bridge units may be placed before the pouring step to embed the bottoms of the bridge units in the cast-in-place concrete.

A bridge system is provided that utilizes foundation structures that are formed of the combination of precast and cast-in-place concrete. A method of constructing the combination precast and cast-in-place concrete foundation structures involves receiving at a construction site a precast concrete foundation unit having elongated upright wall members that define a channel therebetween, and multiple upright supports located within the channel; placing the precast concrete foundation unit at a desired use location; delivering concrete into the channel while the precast concrete foundation unit remains at the desired use location; and allowing the concrete to cure-in-place such that the elongated upright wall members are connected to the cured-in-place concrete by reinforcement embedded within both the cured-in-place concrete and the upright wall members. The bridge units may be placed before the pouring step to embed the bottoms of the bridge units in the cast-in-place concrete.

A fire and/or water resistant expansion joint system for installation between substrates of a tunnel. The system includes a coating applied at a predetermined thickness to the substrates and a fire and water resistant expansion joint. The 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 expansion joint system when installed between the substrates. The coating and the fire and water resistant expansion joint are each capable of withstanding exposure to a temperature of at least about 540 C. or greater for about five minutes.

A structure having at least one flexible material structured and arranged to withstand a tensile load, at least one support structure configured to support the flexible material and structured and arranged to withstand a compressive load, and at least one enclosed volume at least partially defined by the at least one flexible material, the at least one enclosed volume being configured to be maintained as a low-pressure environment

A structure having at least one flexible material structured and arranged to withstand a tensile load, at least one support structure configured to support the flexible material and structured and arranged to withstand a compressive load, and at least one enclosed volume at least partially defined by the at least one flexible material, the at least one enclosed volume being configured to be maintained as a low-pressure environment

A migration prevention system for radioactive wastewater from an underground nuclear power plant. The underground nuclear power plant includes a nuclear island including an underground cavern group including a reactor cavity and auxiliary cavities. The migration prevention system includes a protective layer coating the reactor cavity and an impermeable layer surrounding the nuclear island. The protective layer includes an inner liner, a drainage layer, and a filling layer of rock fractures in that order. The inner liner is configured to prevent exosmosis of the radioactive wastewater of the reactor cavity. The drainage layer is configured to gather and drain seepage water. The impermeable layer is disposed in the periphery of the underground cavern group including the reactor cavity and the auxiliary cavities, and is configured to isolate the underground cavern group from natural underground water.

A migration prevention system for radioactive wastewater from an underground nuclear power plant. The underground nuclear power plant includes a nuclear island including an underground cavern group including a reactor cavity and auxiliary cavities. The migration prevention system includes a protective layer coating the reactor cavity and an impermeable layer surrounding the nuclear island. The protective layer includes an inner liner, a drainage layer, and a filling layer of rock fractures in that order. The inner liner is configured to prevent exosmosis of the radioactive wastewater of the reactor cavity. The drainage layer is configured to gather and drain seepage water. The impermeable layer is disposed in the periphery of the underground cavern group including the reactor cavity and the auxiliary cavities, and is configured to isolate the underground cavern group from natural underground water.

A reinforced concrete structure including a reinforcement made from a plurality of elongate longitudinal members of fibreglass or like material, disposed substantially parallel with one another in at least one predetermined direction. The elongate longitudinal members are coupled to one another by means of coupling members of fibreglass or formed by a strip of flexible polymer material. Metal and/or synthetic fibres are mixed with the concrete matrix to provide the structure with shear strength, making it possible substantially to reduce the number of coupling members.