constructies civiele techniek bouwmanagement bouwkunde installaties Jointless industrial floors Suspended industrial floors on pilesDesign and construction of jointless industrial floorson optimised foundationsABT frequently uses suspended pile foundations in itsendeavours to create an optimal floor design. Cost savingsof 5 to 10% are usually possible.These foundations are often used when the ground doesnot allow shallow foundations on steel, and deep pilefoundation appear unnecessary. The piles then bridge thefirst soft (clay) layer and are driven relatively shallow intothe first good sand layer. Depending on compressibilitya part of the load is even borne by the foundation soil. Itis then often possible to design an economic floor thatsatisfies the highest user requirements.Slender bored piles or prefab piles can be used, but in Figure: settlement prognosis for a suspended floormany cases HSP piles are the most suitable. The HSP pilewas developed to allow banks to function without Floor sizingsettling, but it can also function excellently for floors. HSP If the floor is supported partly by piles and partly by thepiles under the floor must therefore actually be regarded ground, the effects of the forces in the floor areas a settlement reducing measure. There is also no danger determined in a finite element calculation. Here accountof collapse because there is soil below the floor. is taken of the spring stiffness of the floor, the piles and the foundation soil. The floor dimensions are then againThe HSP piles measure Ø180 mm. Because the bearing determined in conformity with the VBC.capacity is relatively low and the piles do not havereinforcement throughout they are not suitable asbuilding foundations. Because up to 3 km of pile lengthcan be produced a day it may justifiably called a HighSpeed Pile.Giving that the floor foundations on small piles reducesthe span, so the effects of the forces in the floor alsodecrease. Then a thinner floor with a high reinforcementpercentage can be used. Cracking susceptibility in thefloor is then greatly reduced; this also ensures improvedliquid sealing. Figure: 3D calculation of the effects of the forces in a floor on piles Maximum pile load In its HSP brochures Voorbij indicates a load up to 200 kN. For floor designs ABT uses a maximum load that is 20% higher. The reason for this is that the pile in an ABT design is always enclosed in rubble and lateral loads cannot result in pile breakage. With a pile diameter of 180 mm the compression stress in the pile only amounts to 9.0 N/ mm2 and this is essentially lower than the strength of theFigure: diagrammatical example of a floor with short piles concrete (C20/27). No protruding bar length is applied soand a foundation with long piles. horizontal forces of eccentricity cannot occur.