General Sequence for Top Down Construction
Construction of Earth Retaining Stabalising System (ERSS) > Install bored piles and plunge in king post > Construct ground floor slab with access openings as working platform. From here, there are 2 directions of construction: downwards to the base (top down process), and upwards for the super-structure construction (conventional bottom up construction).

Top Down Process: Construct main slabs downwards floor by floor till base slab (top down process) > Construct internal columns and walls upwards from base slab till ground (bottom up process when top down construction for the main slabs complete) > Close off access openings.

Construction for a 3-basement building. Top down for the perimeter basement slabs as struts to the retaining walls with king posts. Conventional bottom up for the "core" structures. Project: Audi Center. Contractor: Lum Chang.

Ground floor as working platform for top down construction. Project: CCL Buona Vista Station.

Top down construction for a main slab. DTL1 C902 Promenade Station. Contractor: Shanghai Tunnel.

Hacking away surface concrete to reveal couplers for D wall. DTL1 C902 Promenade Station.