BBCC LUCENTIA FEATURE SPIRAL STAIRCASE

Kuala Lumpur, Malaysia

A unique feature between the 63-storey and the 50-storey condominium block of the BBCC Lucentia project is a dual-level steel bridge that forms part of the shared facility zone of the two buildings. This level features a common roof top infinity swimming pool extending across the bridge between the two towers. The shared facility levels are also interconnected with a 2.5 times full revolution spiral staircase unsupported except at its ends.

The design of the steel bridge across the two towers necessitated intricate wind and earthquake lateral building deflection analytical study to ensure that the towers responded independently to these lateral forces whilst allowing vertical, longitudinal and transverse free movement at one end of the bridge. Pot bearing movement joints capable of accommodating these large relative deflections were detailed at this location.

Interconnecting the two levels of the steel bridge between the two towers is a 25-odd tonne steel spiral staircase supported only at its ends, thus experiencing significant axial, shear, bending and torsional effects.

Intricate 2D static stress analysis, connection stress analysis, linearised buckling analysis, modal analysis, human footfall induced vibration analysis were conducted to ensure that the spiral staircase would be structurally sound, stable and could perform satisfactorily. On-site deflection and vibration measurements were conducted at various stages of the erection to validate the assumptions of the analytical parameters such as the stiffness and damping of the staircase and benchmark its acceleration response.

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Client: BBCC Development Sdn Bhd

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Consultancy Scope: Full Structural and Civil Engineering

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Project Cost: N / A

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Project Status: Completed in 2022