Soil-Framed Structure Interaction Analysis - A New Interface Element

Abstract

Interfacial behavior between soil and shallow foundation has been found so influential to combined soil-footing performance and redistribution of forces in the superstructure. This study introduces a new thin-layer interface element formulated within the context of finite element method to idealize interfacial behavior of soil-framed structure interaction with new combination of degrees of freedom at top and bottom sides of the interface element, compatible with both isoparametric beam and quadrilateral element. This research also tends to conduct a parametric study on respective parameters of the new joint element. Presence of interface element showed considerable changes in the performance of the framed structure under quasi-static loading.

Influence due to interface in finite element modeling of soil-structure interaction system: a study considering modified interface element

“…The thin layer interface element proposed by Dalili et al [24] has been modified for zero thickness as given below. The element is compatible with 2 noded isoparametric beam bending element and 8 noded isoparametric plane strain soil element.…”

“…The element is having a unit thickness; thus, the strain displacement relation has been written in terms of relative displacement of upper and lower nodes as shown in equation 6 [19,24]. Also, it has been reported that the coordinates of upper beam nodes and lower soil top nodes along with interface element nodes are same; hence the element is called a zero-thickness interface element.…”

“…As per Aivazzadeh and Verchery [23], the discontinuous deformations and stresses at the junction of two dissimilar materials are taken care by the interfaces. The presence of interface permits the slip, bonding and de-bonding between soil-structure contacts and redistributes the member forces in structure [15,19,24]. The consideration of bonding and de-bonding in addition to slip at interface has improved the performance of SSI analysis in this paper.…”

“…The solid-to-solid contact element includes modified Goodman's element by Viladkar et al [25], axisymmetric element by Rafael et al [12] and Sharma et al [26]. Whereas solid to skeletal contact element includes 3 noded isoparametric zero thickness interface element proposed by Viladkar et al [19], Noorzaei et al [27] and 5 noded thin layer isoparametric interface element by Dalili et al [24]. These solid to skeletal elements are of special importance as they used to combine variable degree of freedom (DoF) system at interface.…”

“…The execution of zero thickness interfaces in many SSI problems has proved its feasibility. In this paper, the thin layer interface element proposed by Dalili et al [24] has been modified to zero thickness interface with non-linearity for studying the influence of interface in SSI system.…”