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Über dieses Buch

This book provides senior undergraduate students, master students and structural engineers who do not have a background in the field with core knowledge of structural earthquake engineering that will be invaluable in their professional lives. The basics of seismotectonics, including the causes, magnitude, and intensity of earthquakes, are first explained. Then the book introduces basic elements of seismic hazard analysis and presents the concept of a seismic hazard map for use in seismic design. Subsequent chapters cover key aspects of the response analysis of simple systems and building struc­tures to earthquake ground motions, design spectrum, the adoption of seismic analysis procedures in seismic design codes, seismic design principles and seismic design of reinforced concrete structures. Helpful worked examples on seismic analysis of linear, nonlinear and base isolated buildings, earthquake-resistant design of frame and frame-shear wall systems are included, most of which can be solved using a hand calculator.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Nature of Earthquakes

Abstract
This chapter introduces some of the basic concepts in Engineering Seismology that should be familiar to earthquake engineers who analyze and design structures against earthquake induced seismic waves. The majority of these concepts are also used as tools to assess seismic hazard for quantifying earthquake demands on structures. The chapter begins with a summary of the main components of Earth’s interior structure and their interaction with each other in order to describe the physical mechanism triggering the earthquakes. These introductory discussions lead to the definitions of earthquake types, their relation with global plate movements and resulting faulting styles. The magnitude scales for determining the earthquake size as well as primary features of seismic waveforms that are used to quantify earthquake intensity follow through. The characteristics of accelerograms that are mainly used to compute the ground-motion intensity parameters for engineering studies as well as the macroseismic intensity scales that qualitatively inform about the earthquake influence over the earthquake affected area are discussed towards the end of the chapter. The chapter concludes by a brief overview on the effects of earthquake shake on the built and geotechnical environment to emphasize the extent of earthquake related problems and broad technical areas that should be focused by earthquake engineers.
Halûk Sucuoğlu, Sinan Akkar

Chapter 2. Seismic Hazard Assessment

Abstract
This chapter describes the fundamentals of seismic hazard assessment that constitutes the basis in the definition of seismic design forces. The classical probabilistic and deterministic hazard assessment methods are introduced with emphasis on their elementary components. The discussions on common and different elements of probabilistic and deterministic hazard assessment are followed by step-by-step descriptions of each method. The chapter ends with the introduction of uniform hazard spectrum that is one of the main outputs of probabilistic seismic hazard assessment. This concept is implemented in many modern seismic design codes while deriving the elastic seismic forces. As the basis of probabilistic seismic hazard assessment relies on the probability theory, the last part of the chapter is devoted to fundamental topics in probability.
Halûk Sucuoğlu, Sinan Akkar

Chapter 3. Response of Simple Structures to Earthquake Ground Motions

Abstract
Our approach starts with developing response analysis procedures for a single degree of freedom system. We present the derivation of the equations of motion governing its free vibration response (simple harmonic motion) and forced vibration response. Then we solve the equations of motion of undamped and damped systems first under harmonic force excitation by developing classical, closed form analytical solution procedures, and then solve them under earthquake ground excitations by developing numerical solution procedures. This solution under earthquake ground excitations also leads to earthquake response spectra. Finally these procedures are extended to systems with nonlinear force-deformation relations where hysteresis rules are defined and the concepts of ductility, strength, ductility reduction factor, strength spectra and ductility spectra are introduced.
Halûk Sucuoğlu, Sinan Akkar

Chapter 4. Earthquake Design Spectra

Abstract
This chapter introduces the major concepts implemented in seismic design codes for determining the seismic design forces. Two main code streams are emphasized in the entire chapter. The Eurocode 8 (CEN 2004) and NEHRP provisions together with ASCE 7 standards are discussed to describe their approach for determining the minimum seismic design loads. The first part of the chapter discusses the computation of elastic design spectrum and the rest of the text presents the reduction of elastic design spectrum to inelastic design spectrum with the assumption of expected nonlinear behavior in code-conforming buildings. Example problems that are solved after each major topic reinforce the critical concepts discussed throughout the text.
Halûk Sucuoğlu, Sinan Akkar

Chapter 5. Response of Building Frames to Earthquake Ground Motions

Abstract
We introduce seismic response analysis for multi degree of freedom building frame systems, particularly for plane frames in this chapter. The equations of motion are first developed for plane frames under external forces and earthquake ground excitation. Static condensation procedure is employed for defining the dynamic degrees of freedom, hence for reducing the total number of degrees of freedom. Then free vibration analysis is conducted leading to natural vibration modes and frequencies. Modal properties are exploited through mode superposition analysis for obtaining dynamic frame response under base excitation. Mode superposition procedure is specialized into the equivalent static response spectrum analysis under modal spectral forces with modal combination rules. Chapter concludes with two special applications, nonlinear static (pushover) analysis and analysis of base isolated buildings.
Halûk Sucuoğlu, Sinan Akkar

Chapter 6. Analysis Procedures and Seismic Design Principles for Building Structures

Abstract
Seismic analysis procedures and design principles are developed for building structures in this Chapter. Dynamic degrees of freedom are defined at each story by using the rigid diaphragm assumption, leading to a diagonal mass matrix. Stiffness matrix is derived for 3D buildings with unsymmetrical stiffness distribution in plan, leading to a coupled stiffness matrix. The effect of unsymmetrical stiffness distribution on the mode shapes is discussed, with emphasis on torsional coupling. Modal response spectrum analysis and equivalent lateral load procedure are introduced in the general seismic code format. Basic design principles and performance requirements for buildings are reviewed. Structural irregularities given in seismic codes and their effect on analysis procedure selection are discussed. The concept of seismic deformation control associated with interstory drift limits, second order effects and pounding is explained.
Halûk Sucuoğlu, Sinan Akkar

Chapter 7. Seismic Design of Reinforced Concrete Structures

Abstract
Seismic design is based on inherent ductile response, which is manifested by capacity design principles in reinforced concrete buildings. Ductility in reinforced concrete materials and members are discussed in this chapter. The effect of confinement for increasing compressive strain capacity of concrete is explained. Seismic design requirements for providing ductile response of beams, columns and slender shear walls under earthquake loads are evaluated in detail. Strong column-weak beam principle and its implementation in seismic design codes is elaborated. Strength design of non-ductile members, namely beam-column joints and squat shear walls in seismic codes are described. Chapter concludes with a comprehensive design example of a 5-story concrete frame.
Halûk Sucuoğlu, Sinan Akkar

Backmatter

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