Reliability Analysis of Reinforced Concrete Bridge Decks Subject to Fatigue

Reliability Analysis of Reinforced Concrete Bridge Decks Subject to Fatigue

Project / Seminar Material
Reference ID: PS-12932-TM

DEDICATION

This research material titled “Reliability Analysis of Reinforced Concrete Bridge Decks Subject to Fatigue” is dedicated to God for his enabling grace, and to all computer enthusiasts who contributed to make life a pleasant experience during my research documentation.

ACKNOWLEDGEMENT

I extend my sincere gratitude to all those who contributed to the completion of this project. Special thanks to my Supervisor (Name of your Supervisor), the Head of Department (Name of your HOD), the Lecturers in the department of Civil Engineering, Book Authors and Profound Scholars of existing or related project material on “Reliability Analysis of Reinforced Concrete Bridge Decks Subject to Fatigue” for their invaluable guidance, support, and expertise throughout the journey.

I am also grateful to your study area (mention any funding organizations, if applicable) for their financial assistance. This research would not have been possible without the encouragement and assistance of some stakeholders (mention any mentors, teachers, or colleagues). Additionally, I would like to acknowledge the understanding and patience of my family and friends during this endeavor. Your unwavering support has been a constant source of motivation. Thank you all for being part of this meaningful endeavor.

ABSTRACT

In this thesis the reliability analysis of reinforced concrete bridge decks subjected to high cycle fatigue was undertaken. A simply supported (single span) reinforced concrete bridge deck was specifically used for the investigation. The statistical models of capacity loss were derived. The uncertainties in structural resistance and the applied loadings were fully accommodated using probabilistic method. The limit state function(Failure Modes) for the flexural capacity of the deck slab, shear capacity of the deck beam and flexural capacity of the deck beam girder was developed and evaluated using the First Order Reliability Method(FORM).

The entire process was implemented through a developed MATLAB program “dc_fatigue.m”. Analysis was carried out on all the failure modes considered by varying the geometrical and material properties of the system and their respective safety indices were determined. Failure due to shear in the deck beam gave the least safety index range of 6.06 to -2.11 at 3cycles/min for 10years and 40years respectively indicating the most critical section, when compared to the flexural failure with a safety index range value of 7.59 to 0.25 at 3cycles/min for 10years and 40years respectively. It was generally observed that the reliability index increased as the depth of section and concrete grade increased.

Also, the coefficient of variation due to the concrete strength and depth of section decreased with increase in reliability index, from a safety index range of 7.61 to − 0.47 at 5% covariance and from 3.47 to -0.23 at 20% covariance under stress load of 3cycles/min. This trend is expected as quality control plays a very important role in achieving this level of safety in the system. Thus, for a single span bridge of 15m and less under high level of traffic load, a deck beam depth of 1200mm, deck slab of 250mm and concrete strength class of 30-35 are adequate for design and construction.

Reliability Analysis of Reinforced Concrete Bridge Decks Subject to Fatigue

CHAPTER ONE

Introduction

1.1 Preamble

Researches on fatigue behaviour of concrete materials started at the end of the 19th century, due to failure in many concrete structures caused by fatigue rupture of the concrete (Rteil et.al, 2011). Results of experimental and theoretical studies of the fatigue properties of plain concrete, reinforcing bars, prestressing tendons, and also of structural concrete members, have been accumulating steadily over the past thirty years.

The assessment of existing structures will become a more frequent task for engineers in the near future due to the increasing age of existing infrastructure. These may be due to reasons such as(Jansen, 1996); Change in intended use of the structure, new regulations with higher load requirements for the structure, indications of ongoing deterioration in the structure, unusual incidents during use (e.g. vehicle impact, fire, earthquakes), inadequate serviceability, discovery of design or construction errors.

The purpose of reliability analysis in this research is to verify the overall stability and establishment of action effects, i.e. The distribution of internal forces and moments. In turn, this will enable the calculation of stresses, strains, curvature, rotation and displacements. In certain complex structures, the type of analysis used (e.g. finite-element analysis) will yield internal stresses and strains and displacements directly.

…

CHAPTER TWO

2.0 Literature Review

2.1 Introduction

This chapter focuses on the review of related literature. A literature review includes the current knowledge as well as theoretical and methodological contributions to a particular topic. It documents the state of the art with respect to the topic you are writing. It surveys the literature in the topic selected. In this research work the literature review includes the …

Summary Headlines for Reliability Analysis of Reinforced Concrete Bridge Decks Subject to Fatigue