Preface

Recent major earthquakes around the world have shown the vulnerability of infrastructure and the need for research to better understand the nature of seismic events and their effects on structures. As a result, earthquake engineering research has been expanding as more and more data become available from a large array of seismic instruments, large scale experiments and numerical simulations. This book presents results from some of the current seismic research activities including threedimensional wave propagation in different soil media, seismic loss assessment, geotechnical problems including soil-structure interaction, and seismic response of structural components and structures including historical and monumental structures, bridge embankments, and different types of bridges and bearings.

First part of the book deals with seismic risk assessment and hazard analysis with a concentration on seismic microzonation, development of probabilistic hazard maps, geotechnical problems including soil-structure interaction, and three-dimensional wave propagation in different soil media considering different surface characteristics and topography. Chapter 1 provides a methodology for seismic risk assessment within a performance based earthquake engineering framework. Probabilistic hazard analysis and economic models are used for loss estimation and evaluation of earthquake impact on regional economies. Chapter 2 describes development of seismic microzonation and probabilistic hazard maps for a specific region. Details of site characteristics including geological conditions and soil nonlinearity were considered in the seismic zoning and hazard assessment. Chapter 3 presents cognitive methods for modeling geotechnical and seismological problems. New data-driven modern techniques are used to complement and improve the traditional physically-based geotechnical modeling and system analysis under earthquake loading. Chapter 4 includes a new method to simulate three-dimensional seismic wave simulation in heterogeneous transversely isotropic medium with non-flat free surface. Numerical simulations involving different free surfaces provide realistic seismic wave propagation in the vicinity of the earth surface. Wave diffractions, scattering, multiple reflections, and converted waves caused by the free surface topography are studied. Chapter 5 provides ground motion estimates for Sothern California as a case study for seismic hazard analysis in a high seismic region. The numerical simulations include full-wave propagation in three-dimensional velocity models. Chapter 6 includes

#### X Preface

recommendations on soil-structures interaction modeling and provides classification of different modeling approaches based on general superposition of wave fields. Stateof-the-art approaches including those used in nuclear industry are discussed.

The second part of the book is devoted to dynamic behavior structures and their components under earthquake loading. Chapter 7 presents seismic performance and vulnerability of historical and monumental structures based on field observations after major earthquakes and dynamic analysis structural models. Seismic damage observed in a large number of structures are documented and discussed. Chapter 8 provides a methodology for quick seismic assessment and ranking of bridge embankments to identify and prioritize embankments that are susceptible to failure. The methodology is applied to a large number of bridge embankments considering the effect of various site conditions, earthquake magnitudes, and site geometry on possible movement of the embankment. Chapter 9 investigates the deck-stay interaction mechanisms using appropriate initial shapes of cable-stayed bridges. Modal analyses of finite element bridge models are performed under earthquake excitations. Seismic evaluation and dynamic behavior of a 12.9 km long bridge is presented in Chapter 10. Various ground motions that can be expected at the bridge site were selected and used in the dynamic analysis of the finite element model. Chapter 11 investigates the effect of plastic hinge properties on the time-dependent seismic performance of reinforced concrete buildings with and without corroded reinforcement. The last chapter presents results of an experimental research to characterize the mechanical behavior of three types of bearings under biaxial loading. A rate-dependent constitutive model is developed to represent the cyclic shear behavior of laminated rubber bearings. This last topic covered in the book investigates the response of a component while the other chapters mainly focuses on various structures including buildings and bridges.

**Halil Sezen** 

Department of Civil, Environment and Geodetic Engineering at the Ohio State University in Columbus, Ohio, USA

X Preface

recommendations on soil-structures interaction modeling and provides classification of different modeling approaches based on general superposition of wave fields. State-

The second part of the book is devoted to dynamic behavior structures and their components under earthquake loading. Chapter 7 presents seismic performance and vulnerability of historical and monumental structures based on field observations after major earthquakes and dynamic analysis structural models. Seismic damage observed in a large number of structures are documented and discussed. Chapter 8 provides a methodology for quick seismic assessment and ranking of bridge embankments to identify and prioritize embankments that are susceptible to failure. The methodology is applied to a large number of bridge embankments considering the effect of various site conditions, earthquake magnitudes, and site geometry on possible movement of the embankment. Chapter 9 investigates the deck-stay interaction mechanisms using appropriate initial shapes of cable-stayed bridges. Modal analyses of finite element bridge models are performed under earthquake excitations. Seismic evaluation and dynamic behavior of a 12.9 km long bridge is presented in Chapter 10. Various ground motions that can be expected at the bridge site were selected and used in the dynamic analysis of the finite element model. Chapter 11 investigates the effect of plastic hinge properties on the time-dependent seismic performance of reinforced concrete buildings with and without corroded reinforcement. The last chapter presents results of an experimental research to characterize the mechanical behavior of three types of bearings under biaxial loading. A rate-dependent constitutive model is developed to represent the cyclic shear behavior of laminated rubber bearings. This last topic covered in the book investigates the response of a component while the other chapters

of-the-art approaches including those used in nuclear industry are discussed.

mainly focuses on various structures including buildings and bridges.

Department of Civil, Environment and Geodetic Engineering

at the Ohio State University in Columbus, Ohio,

**Halil Sezen** 

USA

**Section 1** 

**Seismic Risk, Hazard, Wave Simulation** 

**and Geotechnical Aspects** 

**Seismic Risk, Hazard, Wave Simulation and Geotechnical Aspects** 

**Chapter 1** 

© 2012 Kalantari, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

© 2012 Kalantari, licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

As has been shown, earthquake events have not only inflicted human and physical damage, they have also been able to cause considerable economic conflict in vulnerable cities and regions. The importance of the economic issues and the consequences of earthquakes attracted the attention of engineers and provided new research and working opportunities

**Seismic Risk of Structures** 

Additional information is available at the end of the chapter

Afshin Kalantari

**1. Introduction** 

http://dx.doi.org/10.5772/50789

**and the Economic Issues of Earthquakes** 

As one of the most devastating natural events, earthquakes impose economic challenges on communities and governments. The number of human and economic assets at risk is growing as megacities and urban areas develop all over the world. This increasing risk has

The 1975 Tangshan (China) earthquake killed about 200,000 people. The 1994 Northridge, (USA) earthquake left 57 dead and about 8,700 injured. The country experienced around \$42 billion in losses due to it. The 1995 earthquake in Kobe (Japan) caused about 6,000 fatalities and over \$120 Billion in economic loss. The August 1996 Izmit (Turkey) earthquake killed 20,000 people and caused \$12 billion in economic loss. The 1999 Chi-chi (Taiwan) earthquake caused an estimated \$8 billion in loss. The 2006 Gujarat (India) earthquake saw around 18,000 fatalities and 330,000 demolished buildings [1]. The Sichuan (China) earthquake, on May 12th 2008 left 88,000 people dead or missing and nearly 400,000 injured. That earthquake damaged or destroyed millions of homes, leaving five million homeless. It also caused extensive damage to basic infrastructure, including schools, hospitals, roads and water systems. The event cost around \$29 billion in direct loss alone [2]. The devastating earthquake of March 2011 with its resulting tsunami along the east coast of Japan is known to be the world's most costly earthquake. The World Bank estimated the cost at \$235 billion while government estimates reported the number at \$305

been plotted in the damage and loss reports after the great earthquakes.

billion. The event left 8,700 dead and more than 13,000 missing [3].
