This eBook is the second in a series of books on the critical earthquake response of elastic-plastic structures or rigid blocks under near-fault ground motions, and includes four original research papers which were published in the specialty section Earthquake Engineering in ‘Frontiers in Built Environment’. Several extensions of the first book1 are included here. The first article is on the soil-structure interaction problem. The reduction of an original soil-structure interaction model into a single-degree-of-freedom (SDOF) model enables the application of the original theory for an SDOF model to such complicated soil-structure interaction model. The second article is concerned with the extension of the original theory for an SDOF model to a 2DOF model. Since the simple application of the original theory for an SDOF model to a multi-degree-of-freedom model is difficult due to out-of-phase phenomenon of multiple masses, a convex model theory is introduced and an upper bound of elastic-plastic response is derived. The third article is related to the stability problem of structures (collapse problems of structures) in which the P-delta effect is included. It is shown that the original theory for an SDOF model with elastic-perfectly plastic restoring-force characteristic can be applied to a model with negative second slope. The fourth article is an application of the energy balance approach to an overturning limit problem of rigid blocks. A closed-form expression of the overturning limit of rigid blocks is derived for the first time after the Housner’s pioneering work in 1963. The approach presented in this book, together with the first book, is an epoch-making accomplishment to open the door for simpler and deeper understanding of structural reliability of built environments in the elastic-plastic and nonlinear range.

This book presents methods and results that cover and extend beyond the state-of-the-art in structural dynamics and earthquake engineering. Most of the chapters are based on the keynote lectures at the International Conference in Earthquake Engineering and Structural Dynamics (ICESD), held in Reykjavik, Iceland, on June 12-14, 2017. The conference is being organised in memory of late Professor Ragnar Sigbjörnsson, who was an influential teacher and one of the leading researchers in the fields of structural mechanics, random fields, engineering seismology and earthquake engineering. Professor Sigbjörnsson had a close research collaboration with the Norwegian Institute of Science and Technology (NTNU), where his research was mainly focused in dynamics of marine and offshore structures. His research in Iceland was mainly focused on engineering seismology and earthquake engineering. The keynote-lecture based chapters are contributed by leading experts in these fields of research and showcase not only the historical perspective but also the most recent developments as well as a glimpse into the future. These chapters showcase a synergy of the fields of structural dynamics, engineering seismology, and earthquake engineering. In addition, some chapters in the book are based on works carried out under the leadership and initiative of Professor Sigbjörnsson and showcase his contribution to the understanding of seismic hazard and risk in Iceland. As such, the book is useful for both researchers and practicing engineers who are interested in recent research advances in structural dynamics and earthquake engineering, and in particular to those interested in seismic hazard and risk in Iceland.

Seismic Performance of Soil-Foundation-Structure Systems presents invited papers presented at the international workshop (University of Auckland, New Zealand, 21-22 November 2016). This international workshop brought together outstanding work in earthquake engineering that embraces a holistic consideration of soilfoundation-structure systems. For example, the diversity of papers in this volume is represented by contributions from the fields of shallow foundation in liquefiable soil, spatially distributed lifelines, bridges, clustered structures (see photo on front cover), sea floor seismic motion, multi-axial ground excitation, deep foundations, soil-foundation-structurefluid interaction, liquefaction-induced settlement and uplift with SFSI. A fundamental knowledge gap is manifested by the isolated manner geotechnical and structural engineers work. A holistic consideration of soil-foundation-structures systems is only possible if civil engineers work collaboratively to the mutual benefit of all disciplines. Another gap occurs by the retarded application of up-to-date research findings in engineering design practices. Seismic Performance of Soil-Foundation-Structure Systems is the outcome from the recognized need to close this gap, since it has been observed that a considerable delay exists between published research findings and application of the principles revealed by the research. Seismic Performance of Soil-Foundation-Structure Systems will be helpful in developing more understanding of the complex nature of responses these systems present under strong earthquakes, and will assist engineers in closing the gaps identified above.

This eBook is the second in a series of books on the critical earthquake response of elastic-plastic structures or rigid blocks under near-fault ground motions, and includes four original research papers which were published in the specialty section Earthquake Engineering in 'Frontiers in Built Environment'. Several extensions of the first book1 are included here. The first article is on the soil-structure interaction problem. The reduction of an original soil-structure interaction model into a single-degree-of-freedom (SDOF) model enables the application of the original theory for an SDOF model to such complicated soil-structure interaction model. The second article is concerned with the extension of the original theory for an SDOF model to a 2DOF model. Since the simple application of the original theory for an SDOF model to a multi-degree-of-freedom model is difficult due to out-of-phase phenomenon of multiple masses, a convex model theory is introduced and an upper bound of elastic-plastic response is derived. The third article is related to the stability problem of structures (collapse problems of structures) in which the P-delta effect is included. It is shown that the original theory for an SDOF model with elastic-perfectly plastic restoring-force characteristic can be applied to a model with negative second slope. The fourth article is an application of the energy balance approach to an overturning limit problem of rigid blocks. A closed-form expression of the overturning limit of rigid blocks is derived for the first time after the Housner's pioneering work in 1963. The approach presented in this book, together with the first book, is an epoch-making accomplishment to open the door for simpler and deeper understanding of structural reliability of built environments in the elastic-plastic and nonlinear range.

This eBook is the fourth in a series of books on the critical earthquake response of elastic or elastic-plastic structures under near-fault or long-duration ground motions, and includes six original research papers which were published in the specialty section Earthquake Engineering in ‘Frontiers in Built Environment’. Several extensions of the first eBook, the second eBook and the third eBook are included here. The first article is on the comparison of earthquake resilience of various building structures including innovative base-isolation systems and control systems. Pulse-type ground motions and resonant harmonic ground motions are used for investigating the earthquake resilience of those innovative building structures. The second article is concerned with the performance of an innovative seismic response controlled system with shear walls and concentrated dampers in lower stories. The resonant one-cycle sine waves and resonant harmonic waves are used as the input ground motions. The third article is related to the robustness evaluation of a base-isolation building-connection hybrid controlled building structure under the critical long-period and long-duration ground motion. The multi impulse is used as a substitute for a long-period and long-duration ground motion and the model reduction to a single-degree-of-freedom (SDOF) system is conducted to propose a simple response evaluation method. The fourth article is an extension of the previously proposed energy balance approach to a damped bilinear hysteretic SDOF system under a double impulse as a substitute for a near-fault ground motion. The energy absorption through viscous damping is incorporated appropriately in the energy balance and the application of the proposed method to actual recorded ground motions is presented. The fifth article is on the robustness evaluation of base-isolation building-connection hybrid controlled building structures considering uncertainties in deep ground. The earthquake ground motion amplitude at the earthquake bedrock is evaluated by the Boore’s stochastic method in 1983 including the fault rupture and the wave propagation into the earthquake bedrock. Then the phase angle property at the earthquake bedrock is investigated by introducing the concept of phase difference which is defined for each earthquake type. A wave at the ground surface nearly resonant to the base-isolation building-connection hybrid controlled building structure is produced by considering uncertainties in deep ground. The sixth article is concerned with the critical response of nonlinear base-isolated buildings considering soil-structure interaction under a double impulse as a substitute for a near-fault ground motion. The complicated model of a nonlinear base-isolated building on ground is modeled into an SDOF system after a few model reduction processes. The approach presented in this eBook, together with the previous eBooks, is an epoch-making accomplishment to open the door for simpler and deeper understanding of structural reliability and resilience of built environments in the elastic-plastic and nonlinear range.

Problems in nonlinear structural dynamics and critical excitation with elastic-plastic structures are typically addressed using time-history response analysis, which requires multiple repetitions and advanced computing. This alternative approach transforms ground motion into impulses and takes an energy balance approach. This book is accessible to undergraduates, being based on the energy balance law and the concepts of kinetic and strain energies, and it can be used by practitioners for building and structural design. This presentation starts with simple models that explain the essential features and extends in a step-by-step manner to more complicated models and phenomena.

This eBook is the third in a series of books on the critical earthquake response of elastic or elastic-plastic structures under near-fault or long-duration ground motions, and includes four original research papers which were published in the specialty section Earthquake Engineering in ‘Frontiers in Built Environment’. Several extensions of the first eBook and the second eBook are included here. The first article is on the earthquake resilience of residential houses after repeated ground motions with high intensity. The 2016 Kumamoto earthquake brought a significant impact on the earthquake resilience of residential houses under repeated ground motions with high intensity in a few days. The necessary strength upgrade withstanding two repeated high-intensity ground motions was found to be 1.5. The second article is concerned with the smart enhancement of earthquake resilience of building structures under both near-fault and long-duration ground motions. A hybrid system of base-isolation and building connection control was proposed and its earthquake resilience to near-fault and long-duration ground motions was evaluated by a double impulse and a multiple impulse. It was demonstrated that the base-isolation is effective for near-fault ground motions and the building connection system using passive dampers is effective for long-duration ground motions. The third article is related to the robustness evaluation of elastic-plastic base-isolated high-rise buildings under resonant near-fault ground motions. The robustness function was introduced to evaluate quantitatively the robustness of elastic-plastic base-isolated high-rise buildings. The fourth article is an extension of the previously proposed energy balance approach to a bilinear elastic-plastic single-degree-of-freedom system under a long-duration sinusoidal ground motion. A historical difficulty in nonlinear vibration posed by Caughey (1960) and Iwan (1961) has been overcome in a smart manner after half a century. The approach presented in this eBook, together with the previous eBooks, is an epoch-making accomplishment to open the door for simpler and deeper understanding of structural reliability and resilience of built environments in the elastic-plastic and nonlinear range.