Nonlinear Analysis of RC Box Culverts Resting on a Linear Elastic Soil

Fabio Minghini,Daniele Baraldi,Nerio Tullini,Enrico Tezzon

doi:10.3844/sgamrsp.2018.30.45

Fabio Minghini, Daniele Baraldi + Show 2 more

Open Access

https://doi.org/10.3844/sgamrsp.2018.30.45

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Abstract

In the analyses presented, the soil-structure interaction is accounted for by means of a FE-BIE approach, in which the structure is modelled with displacement-based beam finite elements, whereas the boundary between structure and substrate is described in terms of surface tractions by means of a boundary integral equation incorporating a suitable Green's function. This mixed formulation ensures full continuity between structure and substrate in terms of displacements and rotations. To take account of structural nonlinearities, potential plastic hinges are defined at the end sections of the beam elements in the form of semi-rigid connections characterized by a rigid-plastic moment-rotation relationship. The incremental analyses carried out emphasize the effectiveness of the model in reproducing collapse mechanisms and stiffness loss of the structure for increasing loads. Moreover, the adopted formulation is able to capture both interfacial shear tractions and vertical normal tractions which develop along the substrate boundary under a variety of loading conditions.

Highlights

In the field of structural engineering, the assessment of the soil-structure interaction represents a challenge for a long time
It is worth noting that these models are appropriate provided that the effects due to transverse interaction between adjacent parts of the soil surface are not significant
As far as numerical methods are concerned, the soilstructure interaction was analyzed following various approaches. Both the foundation and the substrate were discretized using Finite Elements (FEs), which allowed for describing complex soil geometries (Selvadurai, 1979)

Summary

Introduction

In the field of structural engineering, the assessment of the soil-structure interaction represents a challenge for a long time. The following expressions hold: Following a different approach, Cheung and Nag (1968; Wang et al, 2005) substituted piecewise constant tractions into Equation 7a and 7b and directly used those equations to obtain horizontal and vertical displacements of the substrate boundary, respectively. Such an approach assumes the presence of a finite number of spaced links between the foundation beam and the substrate. Making use of Equation 20 and Equation 14 may be rewritten as follows:

D L3 b bHɶ T

Findings

Conclusion