拉力作用下桩基础的有限元分析.pdfVIP

FINITE ELEMENT ANALYSIS OF PILE FOUNDATIONS SUBJECT TO PULL-OUT S.P.G. MADABHUSHI, Cambridge University Engineering Department, UK S.K.HAIGH, Cambridge University Engineering Department, UK ABSTRACT: The behaviour of piles in sand under tensile loading was investigated using finite element analysis and centrifuge modelling, and the results were compared. The implications of using simplified constitutive models are discussed, along with the modelling of interfaces between sand and structure when high degrees of relative movement are seen. The variation of pull-out resistance with soil density, pile size and speed of pull was investigated in an attempt to predict pile behaviour. Keywords: piles piling; mathematical modelling; centrifuge modelling. 1. INTRODUCTION Many structures are constructed using deep piled foundations in order to transfer structural dead load through unstable ground to a solid stratum. The behaviour of these piles acting in compression has been widely studied using numerical modelling, centrifuge modelling and full-scale testing. Upwards tensile loads may however be applied to these piles owing to the action of horizontal wind or wave forces on the structure and the behaviour of the piles under these loads is much less well documented. In this paper, work undertaken at CUED into the behaviour of these tension piles in sand using the techniques of finite element Madabhushi Haigh: The pull-out behaviour of piles. 1 analysis and centrifuge modelling will be described, and their results compared to give an insight into the force-displacement behaviour of these piles. The resistance of these piles to pull-out comes from two major sources, skin friction between pile and soil and suctions generated at the base of the pile as movement occurs. Both of these effects are greatly affected by the generation of excess or suction pore pressures in the soil due to movement of th