A wall unit (V) for a retaining structure (100) comprises a foot portion (1a) and a wall portion (1b), wherein the wall portion (1b) is inclined with respect to the foot portion (1a), so that it extends over the foot portion (1a). Accordingly, the wall unit (1) is stable during construction and assembly. A corner unit (7) for a retaining structure (100) is adapted to engage with two wall units (1). A retaining structure (100) comprises at least one wall unit (1).

A precast, prestressed concrete tank and method that facilitates construction of a primary inner tank within a secondary outer tank, and which permits for the construction of the primary inner tank after the secondary outer tank has been erected, but without requiring insertion through a top of the secondary outer tank, or by tunneling underneath the secondary outer tank, is disclosed. The primary inner tank has an inner wall and the secondary outer tank has an outer wall (precast, prestressed concrete) and wire windings. The primary inner tank is disposed inside of the secondary outer tank. The secondary outer tank has a plurality of first precast outer wall panels, and a temporary construction opening frame. The temporary construction opening frame defines an access doorway during construction of the tank. The temporary construction opening frame is disposed on a foundation base slab.

A precast, prestressed concrete tank and method that facilitates construction of a primary inner tank within a secondary outer tank, and which permits for the construction of the primary inner tank after the secondary outer tank has been erected, but without requiring insertion through a top of the secondary outer tank, or by tunneling underneath the secondary outer tank, is disclosed. The primary inner tank has an inner wall and the secondary outer tank has an outer wall (precast, prestressed concrete) and wire windings. The primary inner tank is disposed inside of the secondary outer tank. The secondary outer tank has a plurality of first precast outer wall panels, and a temporary construction opening frame. The temporary construction opening frame defines an access doorway during construction of the tank. The temporary construction opening frame is disposed on a foundation base slab.

A precast, prestressed concrete tank and method that facilitates construction of a primary inner tank within a secondary outer tank, and which permits for the construction of the primary inner tank after the secondary outer tank has been erected, but without requiring insertion through a top of the secondary outer tank, or by tunneling underneath the secondary outer tank, is disclosed. The primary inner tank has an inner wall and the secondary outer tank has an outer wall (precast, prestressed concrete) and wire windings. The primary inner tank is disposed inside of the secondary outer tank. The secondary outer tank has a plurality of first precast outer wall panels, and a temporary construction opening frame. The temporary construction opening frame defines an access doorway during construction of the tank. The temporary construction opening frame is disposed on a foundation base slab.

A precast, prestressed concrete tank and method that facilitates construction of a primary inner tank within a secondary outer tank, and which permits for the construction of the primary inner tank after the secondary outer tank has been erected, but without requiring insertion through a top of the secondary outer tank, or by tunneling underneath the secondary outer tank, is disclosed. The primary inner tank has an inner wall and the secondary outer tank has an outer wall (precast, prestressed concrete) and wire windings. The primary inner tank is disposed inside of the secondary outer tank. The secondary outer tank has a plurality of first precast outer wall panels, and a temporary construction opening frame. The temporary construction opening frame defines an access doorway during construction of the tank. The temporary construction opening frame is disposed on a foundation base slab.

Described herein are apparatus, systems and methods useful in forming vertical structures.

Described herein are apparatus, systems and methods useful in forming vertical structures.

A precast, prestressed concrete tank and method that facilitates construction of a primary inner tank within a secondary outer tank, and which permits for the construction of the primary inner tank after the secondary outer tank has been erected, but without requiring insertion through a top of the secondary outer tank, or by tunneling underneath the secondary outer tank, is disclosed. The primary inner tank has an inner wall and the secondary outer tank has an outer wall (precast, prestressed concrete) and wire windings. The primary inner tank is disposed inside of the secondary outer tank. The secondary outer tank has a plurality of first precast outer wall panels, and a temporary construction opening frame. The temporary construction opening frame defines an access doorway during construction of the tank. The temporary construction opening frame is disposed on a foundation base slab.

A precast, prestressed concrete tank and method that facilitates construction of a primary inner tank within a secondary outer tank, and which permits for the construction of the primary inner tank after the secondary outer tank has been erected, but without requiring insertion through a top of the secondary outer tank, or by tunneling underneath the secondary outer tank, is disclosed. The primary inner tank has an inner wall and the secondary outer tank has an outer wall (precast, prestressed concrete) and wire windings. The primary inner tank is disposed inside of the secondary outer tank. The secondary outer tank has a plurality of first precast outer wall panels, and a temporary construction opening frame. The temporary construction opening frame defines an access doorway during construction of the tank. The temporary construction opening frame is disposed on a foundation base slab.

Beneficial use structures are disclosed that include coal combustion residuals (CCR) mixed with water and a binder to form a structural material, and adapted to be compacted for use in the formation of the beneficial use structure. Various structures having beneficial uses are described, including compressed air storage facilities and a pumped hydroelectric facility, including such a facility adapted for use with a lock system of a waterway.