Download or read book Liquefaction Induced Building Performance and Near Fault Ground Motions written by Connor Patrick Hayden and published by . This book was released on 2014 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent earthquakes in Chile, New Zealand, and Japan have re-emphasized the damaging consequences of liquefaction on infrastructure. Due to the complexity of the problem and limited well-documented field case histories, liquefaction-induced building settlements are often estimated using empirical correlations developed for free-field sites on level ground that account for post-liquefaction volumetric strains only. Additional effects due to the presence of a structure are not accounted for with these procedures. The earthquake performance of structures founded on liquefiable ground depends on a complex interaction between the soil properties, the ground motion characteristics, and the structural properties. This thesis presents three related research projects that address aspects of the effects of soil liquefaction including near-fault sites. This research thesis is focused on characterizing and selection of near-fault ground motions, geotechnical centrifuge testing of model buildings affected by liquefaction, and the development of field case histories in Chile following the 2010 Maule, Chile earthquake. Earthquake ground motions are important in liquefaction-induced building performance. Ground motions in the near-fault region frequently have intense, double-sided pulses in the velocity-time series that can be very damaging to structures; forward directivity is a leading cause of these pulses. However, pulses do not always occur in the forward directivity region, and some pulses are not caused by forward directivity. The present study used a new, automated algorithm to classify a large database of records as pulse or nonpulse motions. A straightforward model was developed to estimate the proportion of pulse motions as a function of closest site-to-source distance and epsilon of the seismic hazard. Geotechnical centrifuge tests provide valuable insight into the performance of structures affected by liquefaction. An area particularly lacking understanding is the interaction of closely spaced structures subjected to liquefaction. Two well-instrumented centrifuge tests were performed to investigate the response of three types of model structures founded on liquefiable ground in isolated and adjacent configurations. Acceleration, pore water pressure, and settlement measurements indicated that liquefaction-induced settlement of structures depends on a complex interaction of ground motion, soil, and structural characteristics. For the particular scenarios examined in this study, adjacent structures experienced moderately lower foundation accelerations, tended to tilt away from each other, and settled less than isolated structures. The 2010, MW = 8.8, Maule, Chile earthquake caused substantial damage, including liquefaction-induced damage to infrastructure and provides an important opportunity to learn from these field case histories. This project focuses on improved characterization of the subsurface conditions using penetration testing (i.e., SPT and CPT) at a hospital and two bridges that suffered liquefaction-induced damage. The recently constructed hospital has 10 structurally isolated wings varying in height from one to six stories, which provides a unique opportunity to examine the differing response of varying wings. Liquefaction of plastic, silty soils at the hospital resulted in differential settlement, whereas liquefaction of clean, medium-dense sandy soils resulted in lateral spreading and damage to bridge piers.

Download or read book Soil Liquefaction during Recent Large Scale Earthquakes written by Rolando P. Orense and published by CRC Press. This book was released on 2014-04-15 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil Liquefaction during Recent Large-Scale Earthquakes contains selected papers presented at the New Zealand – Japan Workshop on Soil Liquefaction during Recent Large-Scale Earthquakes (Auckland, New Zealand, 2-3 December 2013). The 2010-2011 Canterbury earthquakes in New Zealand and the 2011 off the Pacific Coast of Tohoku Earthquake in Japan have caused significant damage to many residential houses due to varying degrees of soil liquefaction over a very wide extent of urban areas unseen in past destructive earthquakes. While soil liquefaction occurred in naturally-sedimented soil formations in Christchurch, most of the areas which liquefied in Tokyo Bay area were reclaimed soil and artificial fill deposits, thus providing researchers with a wide range of soil deposits to characterize soil and site response to large-scale earthquake shaking. Although these earthquakes in New Zealand and Japan caused extensive damage to life and property, they also serve as an opportunity to understand better the response of soil and building foundations to such large-scale earthquake shaking. With the wealth of information obtained in the aftermath of both earthquakes, information-sharing and knowledge-exchange are vital in arriving at liquefaction-proof urban areas in both countries. Data regarding the observed damage to residential houses as well as the lessons learnt are essential for the rebuilding efforts in the coming years and in mitigating buildings located in regions with high liquefaction potential. As part of the MBIE-JSPS collaborative research programme, the Geomechanics Group of the University of Auckland and the Geotechnical Engineering Laboratory of the University of Tokyo co-hosted the workshop to bring together researchers to review the findings and observations from recent large-scale earthquakes related to soil liquefaction and discuss possible measures to mitigate future damage. Soil Liquefaction during Recent Large-Scale Earthquakes will be of great interest to researchers, academics, industry practitioners and other professionals involved in Earthquake Geotechnical Engineering, Foundation Engineering, Earthquake Engineering and Structural Dynamics.

Download or read book Numerical Analyses of Liquefaction Induced Building Settlement written by Roberto Xavier Luque Nuques and published by . This book was released on 2017 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquefaction-induced settlement of shallow-founded buildings continues to produce significant damage during earthquakes. The state-of-the-practice for estimating liquefaction-induced settlements relies on simplified procedures that do not capture the important shear-induced mechanisms that often control structural settlements. Consequently, building settlement is often underestimated. Performance-based design requires an improved assessment of liquefaction-induced building settlement. Nonlinear dynamic soil-structure-interaction (SSI) effective stress analyses can capture shear-induced liquefaction building settlement mechanisms. However, they are not commonly used in engineering practice due to their lack of validation. Well-documented field case histories of building performance at sites with liquefiable soil provide the opportunity to validate available analytical tools. In this study, five significant buildings with shallow foundations affected by 2010-2011 Canterbury earthquake sequence are back-analyzed to evaluate the capabilities of dynamic SSI effective stress analysis and to gain insights into the mechanisms controlling liquefaction-induced building settlement. Before the back-analyses of field case histories are performed, 36 model case histories of structural performance from a series of geotechnical centrifuge experiments are analyzed. The centrifuge experiments provide a wealth of quantitative time-varying parameters (e.g., pore water pressure, acceleration, and displacements) for detailed examination of the capabilities of the employed analytical model and procedures. The free-field responses measured in the centrifuge experiments are captured well in the numerical analyses, especially in terms of acceleration-time histories and pore water pressure generation during strong shaking. The analyses also captured liquefaction-induced building settlement in the centrifuge experiments reasonably well, although there was a tendency for it to overestimate the amount of measured building settlement. The tendency for and amount of overestimation were greater for cases in which the ground motions induced relatively small settlements (

Download or read book State of the Art and Practice in the Assessment of Earthquake Induced Soil Liquefaction and Its Consequences written by National Academies of Sciences, Engineering, and Medicine and published by . This book was released on 2019-01-30 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquake-induced soil liquefaction (liquefaction) is a leading cause of earthquake damage worldwide. Liquefaction is often described in the literature as the phenomena of seismic generation of excess porewater pressures and consequent softening of granular soils. Many regions in the United States have been witness to liquefaction and its consequences, not just those in the west that people associate with earthquake hazards. Past damage and destruction caused by liquefaction underline the importance of accurate assessments of where liquefaction is likely and of what the consequences of liquefaction may be. Such assessments are needed to protect life and safety and to mitigate economic, environmental, and societal impacts of liquefaction in a cost-effective manner. Assessment methods exist, but methods to assess the potential for liquefaction triggering are more mature than are those to predict liquefaction consequences, and the earthquake engineering community wrestles with the differences among the various assessment methods for both liquefaction triggering and consequences. State of the Art and Practice in the Assessment of Earthquake-Induced Soil Liquefaction and Its Consequences evaluates these various methods, focusing on those developed within the past 20 years, and recommends strategies to minimize uncertainties in the short term and to develop improved methods to assess liquefaction and its consequences in the long term. This report represents a first attempt within the geotechnical earthquake engineering community to consider, in such a manner, the various methods to assess liquefaction consequences.

Download or read book Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions written by Francesco Silvestri and published by CRC Press. This book was released on 2019-07-19 with total page 8083 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions contains invited, keynote and theme lectures and regular papers presented at the 7th International Conference on Earthquake Geotechnical Engineering (Rome, Italy, 17-20 June 2019. The contributions deal with recent developments and advancements as well as case histories, field monitoring, experimental characterization, physical and analytical modelling, and applications related to the variety of environmental phenomena induced by earthquakes in soils and their effects on engineered systems interacting with them. The book is divided in the sections below: Invited papers Keynote papers Theme lectures Special Session on Large Scale Testing Special Session on Liquefact Projects Special Session on Lessons learned from recent earthquakes Special Session on the Central Italy earthquake Regular papers Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions provides a significant up-to-date collection of recent experiences and developments, and aims at engineers, geologists and seismologists, consultants, public and private contractors, local national and international authorities, and to all those involved in research and practice related to Earthquake Geotechnical Engineering.

Download or read book Seismic Hazard and Risk Analysis written by Jack Baker and published by Cambridge University Press. This book was released on 2021-10-21 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic hazard and risk analyses underpin the loadings prescribed by engineering design codes, the decisions by asset owners to retrofit structures, the pricing of insurance policies, and many other activities. This is a comprehensive overview of the principles and procedures behind seismic hazard and risk analysis. It enables readers to understand best practises and future research directions. Early chapters cover the essential elements and concepts of seismic hazard and risk analysis, while later chapters shift focus to more advanced topics. Each chapter includes worked examples and problem sets for which full solutions are provided online. Appendices provide relevant background in probability and statistics. Computer codes are also available online to help replicate specific calculations and demonstrate the implementation of various methods. This is a valuable reference for upper level students and practitioners in civil engineering, and earth scientists interested in engineering seismology.

Download or read book Latest Developments in Geotechnical Earthquake Engineering and Soil Dynamics written by T.G. Sitharam and published by Springer Nature. This book was released on 2021-07-01 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume brings together contributions from world renowned researchers and practitioners in the field of geotechnical engineering. The chapters of this book are based on the keynote and invited lectures delivered at the 7th International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics. The book presents advances in the field of soil dynamics and geotechnical earthquake engineering. A strong emphasis is placed on proving connections between academic research and field practice, with many examples, case studies, best practices, and discussions on performance-based design. This volume will be of interest to research scholars, academicians and industry professionals alike.

Download or read book Risk Management Series Designing for Earthquakes A Manual for Architects written by Federal Emergency Agency and published by FEMA. This book was released on 2013-04-14 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquakes in the United States are regional in their occurrence and while California is famous for its earthquake other states, such as Texas, have much less concern for the threat of temblors. However, architectural practice is becoming increasingly national and global, and the architect in Texas may find that the next project is in California. Thus it has become necessary for the professional architect to have some knowledge of the earthquake problem and how design seeks to control it. Designing for Earthquakes: a Manual for Architects is intended to explain the principles of seismic design for those without a technical background in engineering and seismology. The primary intended audience is that of architects, and includes practicing architects, architectural students and faculty in architectural schools who teach structures and seismic design. For this reason the text and graphics are focused on those aspects of seismic design that are important for the architect to know. Because of its non-technical approach this publication will also be useful to anyone who has an interest and concern for the seismic protection of buildings, including facility managers, building owners and tenants, building committee participants, emergency service personnel and building officials. Engineers and engineering students will also gain from this discussion of seismic design from an architectural viewpoint. The principles discussed are applicable to a wide range of building types, both new and existing. The focus is on buildings that are designed by a team that includes architects, engineers and other consultants.

Download or read book Earthquake Geotechnical Case Histories for Performance Based Design written by Takaji Kokusho and published by CRC Press. This book was released on 2009-06-05 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquake Geotechnical Case Histories for Performance-Based Design is a collection of 26 case histories, each study containing well-instrumented geotechnical and earthquake data. The book is intended to serve as a reference work, since it contains a common scale to develop and implement design methodologies and numerical analyses, so that their re

Download or read book Numerical Investigation of Liquefaction induced Building Settlements and Their Mitigation Through Coupled Foundation Systems written by Yuan Hong and published by . This book was released on 2015 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquake-induced liquefaction phenomenon has long been recognized as one of the most serious problems in geotechnical earthquake engineering and has been studied through many case histories. It is common sense to realize that large earthquakes always directly damage buildings and injure people. However, buildings are sometimes strong enough to survive from the earthquake, but then suffer from other earthquake-induced geotechnical hazards, such as liquefaction-induced settlement and tilt. This research aims to investigate the impact of liquefaction on the settlement of buildings by numerically simulating and analyzing the effects of various parameters inducing settlements. The finite element effective stress analysis software FLIP, developed in Kyoto University, was used for this purpose. Firstly, the model adopted was validated through the results of centrifuge tests available in the literature. All significant material properties, including static parameters and dynamic properties, and a variety of foundation structures and selected input motions were analyzed using FLIP and the related results were compared with those in the literature. Next, various parameters which were deemed to contribute to the magnitude of total and differential settlements were analyzed, with emphasis on the mechanism in inducing the damage of buildings. The numerical results pointed out that taller buildings experience stronger rocking and generate larger vertical stress than shorter buildings and, with the increase in building height, the liquefaction-induced building settlement and foundation rotation worsened. Moreover, it was found that both vertical settlement and foundation rotation decrease with the increase of building width. Several empirical formulas were regressed to describe the relationships of the most significant parameters and their effects on the settlements of buildings. Then, ground improvement techniques were considered as possible mitigation techniques. Traditional ground improvement measures were reviewed and their merits and shortcomings were summarized. Finally, the effects of liquefaction on the settlements of a set of buildings were investigated and then a methodology of minimizing the impact of liquefaction to adjacent buildings by connecting/coupling their foundations with beams was proposed and verified numerically. Results indicate that the proposed coupled foundation system would result in better performance than the traditional techniques during large earthquake events.

Download or read book Seismic Design Criteria for Soil Liquefaction written by J. M. Ferritto and published by . This book was released on 1997-06-01 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Navy has numerous bases located in seismically active regions throughout the world. Safe and effective structural design of waterfront facilities requires calculating the expected site specific ground motion and determining the response of these complex structures to the induced loading. The Navy's problem is further complicated by the presence of soft saturated marginal soils which can significantly amplify the levels of seismic shaking and liquefy as evidenced in the 1939 Loma Prieta earthquake. Liquefaction is a major factor at the waterfront and most of the damage the Navy has sustained from earthquakes can be attributed to it. The presence of unconsolidated loose cohesionless soils and the high water table makes waterfront sites especially vulnerable. This report establishes liquefaction criteria suited for the design of new facilities and upgrade of existing facilities. The criteria developed herein presents reasonable performance standards balancing performance and damage minimization against the cost of implementation.

Download or read book NEHRP Recommended Provisions National Earthquake Hazards Reduction Program for Seismic Regulations for New Buildings and Other Structures Commentary written by United States. Federal Emergency Management Agency and published by . This book was released on 2001 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Liquefaction targeted Ground Motions and Lateral Spreading Driving Stresses written by Ryan A. Rasanen and published by . This book was released on 2019 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquake induced soil liquefaction has been one of the most studied topics in geotechnical engineering over the past 60 years due to its severe impacts on natural and man-made structures. Improving the prediction of liquefaction triggering has already been undertaken for many years, however, in ways that can produce inconsistent, and inaccurate, results in different seismic environments. The first focal point of this thesis is the introduction of a liquefaction-targeted intensity measure that would allow practicing engineers to obtain the benefits of a full probabilistic liquefaction hazard analysis with the same, or less, effort than required by current conventional liquefaction hazard analyses. Lateral spreading is one of the most common, and most severe, effects of liquefaction. Up to three mechanisms are believed to drive lateral spreading. Each of these potential deformation mechanisms is influenced by static shear stresses yet both empirical and semi-empirical procedures for prediction of lateral spreading displacements currently characterize static shear stresses in a crude and incomplete manner. The second focal point of this research was directed toward developing an improved framework for characterizing the initial static shear stresses over a continuous range of site conditions commonly encountered at lateral spreading sites. This framework is intended to lay the foundation for an improved lateral spreading displacement procedure. To accomplish this, numerical analyses were performed to develop a function that can predict the initial static shear stress at depths of lateral spreading interest.

Download or read book Seismic Performance of Soil Foundation Structure Systems written by Nawawi Chouw and published by CRC Press. This book was released on 2017-08-25 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Near fault Seismic Site Response written by Adrian Rodriguez-Marek and published by . This book was released on 2000 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soil Liquefaction During Earthquakes written by I. M. Idriss and published by . This book was released on 2008 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Long duration Ground Motions on Liquefaction Hazards written by Michael W. Greenfield and published by . This book was released on 2017 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil liquefaction during past earthquakes has caused extensive damage to buildings, bridges, dam, pipelines and other elements of infrastructure. Geotechnical engineers use empirical observations from earthquake case histories in conjunction with soil mechanics to predict the behavior of liquefiable soils. However, current empirical databases are insufficient to evaluate the behavior of soils subject to long-duration earthquakes, such as a possible Mw = 9.0 Cascadia Subduction Zone earthquake. The objective of this research is to develop insight into the triggering and effects of liquefaction due to long-duration ground motions and to provide recommendations for analysis and design. Recorded ground motions from 21 case histories with surficial evidence of liquefaction showed marked differences in soil behavior before and after liquefaction was triggered. In some cases, strong shaking continued for several minutes after the soil liquefied, and a variety of behaviors were observed including dilation pulses, continued softening due to soil fabric degradation, and soil stiffening due to pore pressure dissipation and drainage. Supplemental field and laboratory investigations were performed at three sites that liquefied during the 2011 Mw = 9.0 Tohoku earthquake. The recorded ground motions and field investigation data were used in conjunction with laboratory observations, analytical models, and numerical models to evaluate the behavior of liquefiable soils subjected to long-duration ground motions. Observations from the case histories inspired a framework to predict ground deformations based on the differences in soil behavior before and after liquefaction has triggered. This framework decouples the intensity of shaking necessary to trigger liquefaction from the intensity of shaking that drives deformation by identifying the time when liquefaction triggers. The timing-based framework promises to dramatically reduce the uncertainty in deformation estimates compared to conventional, empirically-based procedures.