73 North Wall Quay

Precast Concrete Crosswall Structure Analysis
Retail and Office High-Rise Project

General Notes
This project involves the design and construction of a precast concrete crosswall structure for an eleven-storey high-rise building with a basement and ten storeys above ground. The precast concrete shear walls provide lateral stability, forming a braced structure that ensures strength and durability.

General Requirements
The building consists of precast concrete crosswalls and stairs, designed to create a stable and efficient structure. The internal walls are built using twin walls, while the external walls feature insulated KC walls—a type of twin wall with insulation and an in-situ concrete core. All floor slabs are reinforced in-situ concrete, providing a solid and durable foundation for the structure.

Structural Idealisation
Vertical loads are transferred through reinforced concrete slabs, supported by precast concrete walls that also carry stair landings and other structural elements. These shear walls play a crucial role in ensuring lateral stability for the entire building.

For horizontal loads, two design conditions are considered:

Wind load
Notional horizontal load
The building is braced in its permanent condition, with shear walls forming the main lateral stability system. During the temporary erection phase, loads are transmitted through the reinforced concrete slabs, walls, and columns, with temporary propping ensuring stability until final connections are completed. Once in place, the reinforced concrete slabs act as a diaphragm, transferring horizontal loads to vertical stiffening elements and providing a restoring moment to the structure.

This precast concrete design delivers a highly efficient, stable, and durable solution for a modern high-rise retail and office building.