NPS® Top Down system allows basement and rooftop spaces to be realised quickly without invading external areas, or requiring constraints at the site. It joins self-supporting characteristics and speed of NPS® execution with the need to realise basement and rooftop structures capable of absorbing horizontal stress, eliminating the need for structural accessory members that anchor walls, or supporting walls (tie-rods and struts).
The beam absolves strut function and the ceiling bearing member at the same time. NPS® Top Down allows the digging phase to happen at the same time as ceiling positioning operations.
The NPS® Top Down system is recommended when it is essential to limit the impact of building sites, i.e., in heavily infrastructured urban contexts and in historic town centres.
Thanks to the high axial rigidity of the decks, deflection of the surrounding ground, subsidence and the risk of slipping of neighbouring buildings are avoided.
It is well applicable, even in the case of large span decks, to counteract soil and water thrusts, and to limit critical points in the verification of buoyancy. Care must be taken when studying the slots that must be left in the roof for the movement of materials and for casting.
Excavation and diaphragm laying. Beam laying level 0
Shoring and Beam Laying Level -1
Shoring and Beam Laying Level -2
Stripping and pouring of foundations
Laying of last beam level -2 and slab level -2
Laying of last beam level -1 and slab
Laying last beam level 0 and slab completion