Preface

Civil structures and infrastructure, particularly roadways and bridges, face multiple lifelong obstacles caused by environmental impacts, such as corrosion, microstructural defects, cracks, thermal and residual stresses, instability, bond failures, and natural disasters like earthquakes and floods. With the advancement of the transportation industry, the scale of bridge, highway, and road construction is growing and construction quality has become an essential factor in transportation projects. The quality of bridge, highway, and road works is not only influenced by material choice, construction team, and management quality but also technology. This book presents new solutions in bridge, highway, and road design and construction to improve the quality of bridge, highway, and road safety.

The book begins with a brief introduction to the design, construction, and retrofitting of bridges, highways, and roads. For the design and construction of bridge structures, it presents current optimization methods using soft computing techniques to address sustainable design and construction of bridges. In addition, the book discusses gaps in bridge optimizations and proposes suggestions for future research. It also introduces an innovative approach for assessing the cross-sectional distribution of live loads on bridge beam-deck systems, reducing the structural problem from multiple degrees of freedom system to two degrees of freedom system. The book investigates the reconstruction of historic bridge deck systems using a case study as well as highway construction challenges. It discusses highway management systems in Iraq that require serious examination and modification. Finally, the book proposes a sustainable trenchless drainage system for road construction on flat terrains.

I hope that readers will find this book useful and I warmly welcome comments, suggestions, and criticisms.

> **Khaled Ghaedi, Ph.D.** PASOFAL Engineering Group, Kuala Lumpur, Malaysia

**1**

**Chapter 1**

**1. Introduction**

Introductory Chapter: Design,

Construction, and Retrofit of

Bridges, Roads, and Highways

*Khaled Ghaedi, Meisam Gordan, Ahad Javanmardi,* 

Bridges are structures designed to support traffic and other dynamic loads induced

by vehicle loads to pass through natural or manmade obstacles. Types of pathways may be roads, highways, railroads, pipeline waterways, or pedestrians. Obstacles can be categorized as canals, rivers, mountains, valleys, lakes, seas, and other manmade structures, such as buildings, rail lines, roads, and bridges themselves. A bridge is a vital structure of modern roadway and railway systems and largely serves as the lifeline of public infrastructure. Apart from bridge structures, Roads and highways are commonly considered important to new-fashioned life and they play an important role in the advancement of cities. The lack of quantifiable sustainability methods creates gaps in sustainability knowledge, leading to the public, and environmental and financial dissatisfaction with completed highways and urban roads. This chapter discusses the key points in design and construction assessment of bridges, highways, and roads covered in the present book in order to bridge the knowledge gap. The discussed topics such as bridge optimization techniques, risk assessment of roads, highway management systems, and challenges in highway construction presented in the book chapters help to provide insights into the bridges and roads' impacts on the environment and the benefits of adopting development assessment systems to

Civil structures and infrastructure, in particular roadways and bridges, have multiple lifelong obstacles caused by various reasons of environmental impact such as corrosion, microstructural defects, cracks, thermal and residual stresses, instability, bond failures, or natural disasters such as earthquake and flood [1–3]. Damage to structural elements affects structural properties such as mass, stiffness, and damping, resulting in changes in the dynamic response of the structure such as natural frequency, modal shape, and damping ratio [4–9]. Therefore, actual solutions can play an essential role in ensuring the safety and reliability of structures. In recent decades, the advancement of road and bridge structures along with their optimization in design and construction has attracted much attention. Development and structural optimization based on mathematical and numerical analysis have resulted in strategies

*Hamed Khatibi and Ramin Vaghei*

increase safety of bridge structures, roads, and highways.

**1.1 Challenges and solutions**
