Deep Foundations on Bored and Auger Piles, Van Impe (ed.) © 2003 Millpress, Rotterdam, ISBN 90-77017-76-3
On the ultimate vertical load of piled rafts on soft clay soils Luca de Sanctis Department of Civil Engineering, Second University of Napoli, Italy
Alessandro Mandolini Department of Civil Engineering, Second University of Napoli, Italy
Keywords: unpiled raft, pile group, piled raft, ultimate load ABSTRACT: The usual design of a piled raft is based on bearing capacity approach and neglects the contribution of the raft. As a consequence piled rafts are usually designed by overconservative criteria. If the raft does not provide adequate load capacity, then the primary reason to add the piles is that of achieving a suitable safety factor against failure. With respect to the traditional approach a more rational and economical solution could be achieved by accounting for the contribution of the raft. In any case, to assess in a rational way the safety of a piled raft, its bearing capacity has to be defined. The subject is discussed on the basis of 3D finite element predictions; simple rules to derive the ultimate vertical load of a piled raft from the collapse loads of its components, such as those obtained by the conventional bearing capacity theory, are presented.
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On the ultimate vertical load of piled rafts on soft clay soils Luca de Sanctis Department of Civil Engineering, Second University of Napoli, Italy
Alessandro Mandolini Department of Civil Engineering, Second University of Napoli, Italy
Keywords: unpiled raft, pile group, piled raft, ultimate load ABSTRACT: The usual design of a piled raft is based on bearing capacity approach and neglects the contribution of the raft. As a consequence piled rafts are usually designed by overconservative criteria. If the raft does not provide adequate load capacity, then the primary reason to add the piles is that of achieving a suitable safety factor against failure. With respect to the traditional approach a more rational and economical solution could be achieved by accounting for the contribution of the raft. In any case, to assess in a rational way the safety of a piled raft, its bearing capacity has to be defined. The subject is discussed on the basis of 3D finite element predictions; simple rules to derive the ultimate vertical load of a piled raft from the collapse loads of its components, such as those obtained by the conventional bearing capacity theory, are presented.
379
