Innovative Earthquake Soil Dynamics

Prof. Takaji Kokusho is Professor Emeritus at Chuo University since 2015. He obtained his BS and MS degrees from the University of Tokyo, and a MS degree at Duke University, USA. He completed his PhD (Doctor of Engineering) at the University of Tokyo in 1982 on the topic of "Dynamic soil properties and nonlinear seismic response of ground.". Takaji worked at the Central Research Institute of Electric Power Industry (CRIEPI) between 1969 and 1995 as researcher, head, and director of Siting Technology for Earthquake Geotechnology. He wasProfessor at the department of Civil and Environmental Engineering at Chuo University between 1996 and 2015. In this time, he published more than 100 reviewed research papers in national and international journals and conference proceedings, and served as a chairman of Technical Committee No. 4 of ISSMGE (2005-2009), Earthquake Geotechnical Engineering, and Asian Technical Committee ATC3 of ISSMGE (1998-2005), and Geotechnology for Natural Hazards.

"The book Innovative Earthquake Soil Dynamics is very appropriately titled and reflects the unique background and extensive expertise of the author, Dr. Takaji Kokusho, Emeritus Professor, Chuo University, Tokyo, Japan. The book is composed of six chapters that can be grouped into four categories: background material (Chapters 1-3), site amplification and dynamic soil-structure-interaction (Chapter 4), liquefaction and related phenomena (Chapter 5), and earthquake-induced slope failure (Chapter 6). The background material presented in Chapters 1-3 gives an in depth coverage of elastic wave propagation in soil, dynamic soil properties, and soil modeling and sets the stage for the topics covered in the latter chapters.Innovative Earthquake Soil Dynamics is unique from other books on geotechnical aspects of earthquake engineering in that it includes a detailed coverage of soil dynamics, as related to earthquake engineering, in addition to the oft-presented empirical relationships. The book is innovative in that it presents the material from both "traditional" (e.g., stress-, strain-, and force-based perspectives) and "energy" perspectives, with the latter largely derived from the author’s own extensive research. The author shows that energy is central to site amplification and dynamic soil-structure-interaction and can be used as a simple index for evaluating liquefaction and related phenomena and earthquake-induced slope failures. Another unique aspect of Innovative Earthquake Soil Dynamics stems from the author having received his higher education in both the United States (Duke University) and Japan (University of Tokyo), and having spent the first half of his career working for the electric power industry in Japan and the second half of his career as a professor at Chuo University. As a result, the material presented in the book reflects research and engineering procedures from both Japan and the United States, as well as other countries, and all the material presented builds to applications in engineering practice. The book is equally suited to serve as a text for graduate courses in geotechnical aspects of earthquake engineering and soil dynamics or as a reference book for practicing engineers."Russell A. Green, Professor of Civil and Environmental Engineering at Virginia Tech, Blacksburg, Virginia, USA.

• PrefaceChapter 1. Elastic wave propagation in soil1.1. Introduction1.2. One-dimensional wave propagation and wave energy1.3. Three-dimensional body waves1.4. Surface waves1.5. Viscoelastic model and soil damping for wave propagation1.6. Wave attenuation by internal damping1.7. Wave attenuation including geometric damping1.8. SummaryChapter 2. Soil properties during earthquakes2.1. Characterization of dynamic soil properties2.2. How to measure soil properties2.3. Typical small strain properties2.4. Strain-dependent equivalent linear properties2.5. SummaryChapter 3. Soil modeling for dynamic analysis and scaled model test3.1. Modeling of soil properties3.2. Dynamic soil analyses3.3. Scaled model tests and soil model3.4. SummaryChapter 4. Seismic site amplification and wave energy4.1. Soil condition and site amplification4.2. Amplification in two-layer system4.3. Site amplification by earthquake observation4.4. Site amplification derived from vertical array records4.5. SSI and radiation damping in one-dimensional wave propagation4.6. Energy flow in wave propagation4.7. SummaryChapter 5. Liquefaction5.1. Typical Liquefaction Behavior5.2. General conditions for liquefaction triggering5.3. Geotechnical conditions for liquefaction triggering5.4. Effect of gravels and fines5.5. Liquefaction potential evaluation by in situ tests5.6. Energy-based liquefaction potential evaluation5.7. Effect of incomplete saturation5.8. Effect of initial shear stress5.9. Cyclic softening of clayey soils5.10. Liquefaction-induced failure and associated mechanism5.11. Base-isolation during liquefaction5.12. SummaryChapter 6. Earthquake-induced slope failures6.1. Slip-surface analysis by seismic coefficient6.2. Newmark method6.3. Self-weight deformation analysis using degraded moduli6.4. Energy-based slope failure evaluation6.5. Case histories and back-calculations by energy-based method6.6. Summary