Pile Forces in Integral Abutment Bridges Subjected to Truck Loads

Author(s):  
Shehab Mourad ◽  
Sami W. Tabsh

Interest in the use of integral bridges has increased in recent years because of their economy, reliability, and strength. However, most of the published research on integral bridges has been concerned with determination of the thermal effect, creep analysis, and seismic behavior. Few studies on live load analysis of integral abutment bridges have been carried out. The pile load behavior of integral abutments supporting composite steel superstructures subjected to gravity loads is investigated. The applied loading is composed of one or more side-by-side HS20-44 trucks. The finite element method is used to analyze the three-dimensional bridge system and determine forces in the piles. A parametric study is performed to obtain the effects of the number of trucks and their location, superstructure geometry, pile spacing and stiffness, pile connection type, and wingwall length on the pile loads. A simple, approximate procedure for computing pile loads is developed on the basis of the findings of the finite element analysis. The results indicate that the abutment-wingwall system does not behave as a rigid block as in the conventional case of a footing on flexible piles. Also, the generated bending moment in the piles caused by gravity load is significant and cannot be neglected in design.

2021 ◽  
Vol 11 (11) ◽  
pp. 5031
Author(s):  
Wooseok Kim ◽  
Jeffrey A. Laman ◽  
Farzin Zareian ◽  
Geunhyung Min ◽  
Do Hyung Lee

Although integral abutment bridges (IABs) have become a preferred construction choice for short- to medium-length bridges, they still have unclear bridge design guidelines. As IABs are supported by nonlinear boundaries, bridge geometric parameters strongly affect IAB behavior and complicate predicting the bridge response for design and assessment purposes. This study demonstrates the effect of four dominant parameters: (1) girder material, (2) bridge length, (3) backfill height, and (4) construction joint below girder seats on the response of IABs to the rise and fall of AASHTO extreme temperature with time-dependent effects in concrete materials. The effect of factors influencing bridge response, such as (1) bridge construction timeline, (2) concrete thermal expansion coefficient, (3) backfill stiffness, and (4) pile-soil stiffness, are assumed to be constant. To compare girder material and bridge geometry influence, the study evaluates four critical superstructure and substructure response parameters: (1) girder axial force, (2) girder bending moment, (3) pile moment, and (4) pile head displacement. All IAB bridge response values were strongly related to the four considered parameters, while they were not always linearly proportional. Prestressed concrete (PSC) bridge response did not differ significantly from the steel bridge response. Forces and moments in the superstructure and the substructure induced by thermal movements and time-dependent loads were not negligible and should be considered in the design process.


Author(s):  
M Taylor ◽  
E W Abel

The difficulty of achieving good distal contact between a cementless hip endoprosthesis and the femur is well established. This finite element study investigates the effect on the stress distribution within the femur due to varying lengths of distal gap. Three-dimensional anatomical models of two different sized femurs were generated, based upon computer tomograph scans of two cadaveric specimens. A further six models were derived from each original model, with distal gaps varying from 10 to 60 mm in length. The resulting stress distributions within these were compared to the uniform contact models. The extent to which femoral geometry was an influencing factor on the stress distribution within the bone was also studied. Lack of distal contact with the prosthesis was found not to affect the proximal stress distribution within the femur, for distal gap lengths of up to 60 mm. In the region of no distal contact, the stress within the femur was at normal physiological levels associated with the applied loading and boundary conditions. The femoral geometry was found to have little influence on the stress distribution within the cortical bone. Although localized variations were noted, both femurs exhibited the same general stress distribution pattern.


2013 ◽  
Vol 421 ◽  
pp. 747-750
Author(s):  
Meng Sha Liu ◽  
Ying Huang ◽  
Jin San Ju

In this paper, a three-dimensional model of a steel sculpture was analyzed by using the finite element software ANSYS. The structural static response were achieved respectively under gravity load, ice load and wind load based on wind tunnel tests with the dynamic response under earthquake action. Besides, the structural parameters such as strength and stiffness under different conditions were also got. It is hoped that the analysis of ultrahigh steel sculpture will offer some technical support for practical engineering.


Author(s):  
Suhail Albhaisi ◽  
Hani Nassif

This paper presents a simple approach to calculate the displacements and the rotations induced by thermal loading in integral abutment bridges (IABs). The approach was derived from the results of a parametric study that investigated the effect of substructure stiffness on the performance of short- and medium-length steel IABs built on clay and sand under thermal load effects. Various parameters, such as pile size and orientation, pile material, and foundation soil stiffness, were considered in the study. Detailed three-dimensional (3-D) finite element (FE) models using the software LUSAS were developed to capture the overall behavior of IABs. The developed 3-D FE model was calibrated with field measurements obtained from a previous study. A parametric study was carried out with the calibrated models to study the effects of the above parameters on the performance of IABs under thermal loading using the AASHTO load and resistance factor design temperature ranges. The study showed that most parameters have significant effects on the displacement and rotation of the abutment and the supporting piles. Also, for relatively wide IABs, there were significant variations in the displacement and rotations in the substructure elements between interior and exterior locations. This approach, which used simple equations and charts and included parameters such as the length of the bridge, the stiffness of the foundation soil, and the pile location, provided results that were comparable with those of a detailed FE analysis.


2014 ◽  
Vol 699 ◽  
pp. 388-394 ◽  
Author(s):  
Thevaneyan K. David ◽  
John P. Forth

Temperature effects are significant to the sustainability of integral abutment bridges with the elimination of expansion joints. The thermally induced lateral movement of the structural components is opposed by the backfill soil supporting the components of integral abutment bridges. A 2D finite element analysis was performed on a typical integral abutment bridge using OASYS SAFE to investigate the complex interactions that exist between the pile supporting stub-type integral abutment and the backfill soil. The primary objective of this paper is to compare the effect of various soil types on the displacement of the piles when subjected to lateral loading and secondly to identify the significance of cyclic lateral load on the behaviour of the piles for various foundation soil types. The results suggest similar effect on the integral pile displacements for investigated soil types, especially for non-cyclic lateral loading.


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