Master of Science / Department of Civil Engineering / Dunja Peric / Integral Abutment Bridges (IABs) are Jointless Bridges whereby the deck is continuous and monolithic with abutment walls. IABs are outperforming their non-integral counterparts in economy and safety. Their principal advantages are derived from the absence of expansion joints and sliding bearings in the deck, making them the most cost-effective system in terms of construction, maintenance, and longevity. The main purpose of constructing IABs is to prevent the corrosion of structure due to water seepage through joints. The simple and rapid construction provides smooth, uninterrupted deck that is aesthetically pleasing and safer for riding. The single structural unit increases the degree of redundancy enabling higher resistance to extreme events. However, the design of IABs not being an exact science poses certain critical issues. The continuity achieved by this construction results in thermally induced deformations. These in turn introduce a significantly complex and nonlinear soil-structure interaction into the response of abutment walls and piles of the IAB. The unknown soil response and its effect on the stresses in the bridge, creates uncertainties in the design. To gain a better understanding of the mechanism of load transfer due to thermal expansion, which is also dependent on the type of the soil adjacent to the abutment walls and piles, a 3D finite element analysis is carried out on a representative IAB using state-of-the-art finite element code ABAQUS/Standard 6.5-1. A literature review focusing on past numerical models of IABs is presented followed by details of the numerical model developed in this study using the interactive environment ABAQUS/CAE 6.5-1 along with the analysis details. A discussion of results for the analysis of the IAB with three different soil conditions and each experiencing three different temperature change scenarios is presented. Conclusions of the study and recommendations for future research wrap up the thesis. The advancement of knowledge enabled by this research will provide a basis for introduction of new guidelines in Kansas Bridge Design Manual.

The advantages of Integral Abutment Bridges (IABs) include reduced maintenance costs and increased useful life spans. However, comprehensive and practical analysis tools for design of IABs have not been developed to account for the impacts of thermal displacements on abutment and foundation components, including the components of mechanically stabilized earth (MSE) walls that are often used around the abutment piling. During this research, over 65 three-dimensional numerical analyses were performed to investigate and quantify how different structural and geotechnical bridge components behave during thermal expansion and contraction of the bridge deck. In addition, separate three-dimensional numerical models were developed to evaluate the usefulness of corrugated steel pipes around the abutment piles. The results of this research quantify the influence of design parameter variations on the effects of thermal displacement on system components, and thus provide guidelines for IAB design, where none had existed before. One of the findings is that corrugated steel pipes around abutment piles are not necessary. One of the most important products of this research is an easy-to-use Excel spreadsheet, named IAB v2, that not only quantifies the impact of thermal displacement in the longitudinal direction, but also in the transverse direction when the abutment wall is at a skew angle to the bridge alignment. The spreadsheet accommodates seven different pile sizes, which can be oriented in weak or strong directions, with variable offset of the abutment from the MSE wall and for variable skew angles. The spreadsheet calculates the increment of displacements, forces, moments, and pressures on systems components due to thermal displacement of IABs. / Ph. D.

The term ???Integral Abutment Bridges??? is used broadly all over the world these days. While the expansion joints used in bridges were once a scientifically proved cure to the problem of natural expansion and contraction, there are the excessive maintenance costs being accumulated annually due to the deterioration of essential functions from deicing chemicals and debris. This drawback triggered the advent of Integral Abutment Bridges. The performance of Integral Abutment Bridges at almost no extra costs in seasonal and daily cyclic contraction and expansion can be assessed as a monumental landmark of civil engineering technologies with respect to the massive budget reductions. However, since Integral Abutment Bridges are destined to expand or contract under the laws of nature, the bridge design became more complicated and sophisticated in order to complement the removal of expansion joints. That is why numerous researchers are attracted to Integral Abutment Bridges with deep interests. Accordingly, in designing the piled abutments of Integral bridges, it is essential to precisely predict the bridge???s behavior in advance. Researchers have been broadly carried out during the last several decades on the behavior of piled bridge abutments. However, most of the studies have been analyzed with focus on structural elements or soils, respectively for the static and dynamic loads such as thermal variations and earthquake loads. This presented research developed 3D numerical models with 3 m, 4 m, 5 m, 6 m, 7 m, and 8 m-tall abutments in the bridge using the finite element analysis software MIDAS CIVIL that simulate the behaviors of Integral Abutment Bridges to study the soil-structure interaction mechanism. In addition, this work evaluated and validated the suitability to the limit of the abutment height in Ontario???s recommendations for Integral Abutment Bridges by a parametric study under the combined static loading conditions. In order to be a balanced research in terms of a multidisciplinary study, this research analyzed key facts and issues related to soil-structure interaction mechanisms with both structural and geotechnical concerns. Moreover, the study established an explanatory diagram on soil-structure interaction mechanisms by cyclic thermal movements in Integral Abutment Bridges.