TL;DR: In this article, the authors focus on designing adequate displacement and ductility capacity into new bridges, with less significance placed on strength, where a strength hierarchy is established in a bridge to ensure that damage is controllable and occurs only where the designer intends.
Abstract: This book should be of interest to practicing bridge designers and researchers investigating the seismic design of bridges It is appropriate for graduate courses or upper level undergraduate courses in seismic design of bridges The approach relies heavily on the principles of capacity design, where a strength hierarchy is established in a bridge to ensure that damage is controllable and occurs only where the designer intends This approach, which is well established for seismic design of buildings, has been extended and modified to reflect the special demands and characteristics of bridges Particular emphasis is placed on designing adequate displacement and ductility capacity into new bridges, with less significance placed on strength The book is developed around two alternative design strategies: the traditional force-based approach where force levels are related to acceleration spectra, with checks to ensure adequate displacement capacity exists, and the newer displacement-based design approach, where displacements are the starting point in the design Introductory chapters discuss design philosophy and its impact on the performance of bridges in recent earthquakes, seismicity and soils effects, including liquefaction, in a form facilitating understanding by structural engineers, and the importance of rational consideration, from a seismic design viewpoint, of the various structural configuration possibilities in the conceptual design phase Extensive discussion of analysis is provided in Chapter 4, with emphasis on the importance of realistic modeling assumptions and appropriate choice of analytical tools Chapters 5 to 8 provide detailed information on the design of new bridges and the assessment and retrofit of existing bridges A separate chapter is devoted to design and retrofit using seismic isolation and dissipation devices Many design and analysis examples, some quite extensive in scope, are included Design aids in the form of charts and tables are also provided An index is provided
TL;DR: In this paper, a comprehensive assessment of recent developments of nonlinear isolators in the absence of active control means is presented, which highlights resolved and unresolved problems and recommendations for future research directions.
TL;DR: In this paper, the authors proposed a linear theory of base isolation for earthquake-resilient building construction and extended it to buildings, and showed that the theory can be applied to the construction of very flexible structures.
Abstract: 1 Seismic Isolation for Earthquake-Resistant Design.- 1.1 Introduction.- 2 Vibration Isolation.- 2.1 Introduction.- 2.2 Theory of Vibration Isolation.- 2.3 Frictional Vibration Isolators.- 3 Seismic Isolation.- 3.1 Review of Fixed-Base Structural Analysis.- 3.2 Linear Theory of Base Isolation.- 3.3 Isolation of Very Flexible Structures.- 4 Extension of Theory to Buildings.- 4.1 M-Degree-of-Freedom Equations of Motion.- 4.2 Modal Analysis of M-DOF System.- 4.3 Estimates of Displacements and Forces for M-DOF System.- 5 Earthquake Regulations for Seismically Isolated Structures.- 5.1 Introduction.- 5.2 1994 Uniform Building Code.- 5.3 Design Methods.- 5.4 Static Analysis.- 5.5 Dynamic Analysis.- 5.6 Computer Programs for Analysis of Seismically Isolated Structures.- 5.7 Other Requirements for Nonstructural Components.- 5.8 Review.- 5.9 Design Requirements for Isolators.- 5.10 Base-Isolated Structures under Extreme Earthquake Loading.- 6 Coupled Lateral-Torsional Response of Seismically Isolated Buildings.- 6.1 Introduction.- 6.2 Case I: Three Close Frequencies.- 6.3 Case II: Equal Lateral Frequencies, Distinct Torsional Frequency.- 7 Behavior of M?ltilayered Bearings Under Compression and Bending.- 7.1 Introduction.- 7.2 Shear Stresses Produced by Compression.- 7.3 Bending Stiffness of a Single Pad.- 7.4 Pure Compression of Single Pads with Large Shape Factors.- 7.5 Compression Stiffness for Circular Pads with Large Shape Factors.- 7.6 Compression Stiffness for Square Pads with Large Shape Factors.- 7.7 Bending Stiffness of Single Pads with Large Shape Factors.- 8 Buckling Behavior of Elastomeric Bearings.- 8.1 Stability Analysis of Bearings.- 8.2 Stability of Annular Bearings.- 8.3 Influence of Vertical Load on Horizontal Stiffness.- 8.4 Downward Displacement of the Top of a Bearing.- 8.5 A Simple Mechanical Model for Bearing Buckling.- 8.6 Postbuckling Behavior.- 8.7 Influence of Compressive Load on Bearing Damping Properties.- 8.8 Rollout Stability.- 9 Design Process for Multilayered Elastomeric Bearings.- 9.1 Preliminary Bearing Design Process.- 9.2 Experimental Studies of Elastomeric Isolator Performance.- 9.3 Compact Design Bearings.- Afterword.- References.- Appendix A.- A.I Base-Isolated Buildings and Projects in the United States.- A.2 Retrofit Base-Isolated Buildings and Projects in the United States.- Appendix B.- B.I N-PAD.- B.2 3D-BASIS.- B.3 SADSAP.- B.4 General Nonlinear Three-Dimensional Analysis Programs.
TL;DR: The concept of seismic or base isolation as a means of earthquake protection seems to be more than 100 years old as discussed by the authors, however, until very recently, few structures were built using this principle.
Abstract: The concept of seismic or base isolation as a means of earthquake protection seems to be more than 100 years old. However, until very recently, few structures were built using this principle. Today the concept has matured into a practical reality and is taking its place as a viable alternate to conventional (fixed base) seismic resistant construction. This paper reviews some of the history of isolation and restates the basic elements of a modern isolation system. It then proceeds to review current activity, worldwide. Progress in the United States is discussed first followed by that in China, France, Greece, Italy, Japan, New Zealand and the Soviet Union. Directories of isolated structures in the United States, New Zealand and Japan are also included. Finally the performance of a selection of these structures during actual earthquakes is given.
TL;DR: In this article, three analytical studies of base-isolated structures are carried out, and the effect of isolation damping on the performance of different isolation systems under near-fault motion is investigated.