INTERACTIVE ANALYSIS OF A SPACE FRAME RAFT SOIL SYSTEM CONSIDERING SOIL NONLINEARITY

A new approach for the physical and material modelling of a space fram e-raft-soil system is presented. The physical modelling consists of a modified Timoshenko beam bending element with six degrees of freedom p er node to model the beams and columns of the superstructure, a modifi ed Mindlin's plate bending element with five degrees of freedom per no de to represent the structural slabs and raft, and the coupled finite- infinite elements with three degrees of freedom per node to model the soil media. The constitutive modelling involves the use of the hyperbo lic model to account for the soil nonlinearity. The applicability of t he proposed physical model is demonstrated by analysing a four-storey, five- by three-bay space frame. An attempt is also made to compare th e linear and nonlinear interactive behaviour of the space frame-raft-s oil system.