A Practical Approach For Implementing The Probability Of Liquefaction In Performance Based Design,
2010
Tufts University, Medford, MA
A Practical Approach For Implementing The Probability Of Liquefaction In Performance Based Design, Thomas Oommen, Laurie G. Baise
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Empirical Liquefaction Models (ELMs) are the usual approach for predicting the occurrence of soil liquefaction. These ELMs are typically based on in situ index tests, such as the Standard Penetration Test (SPT) and Cone Penetration Test (CPT), and are broadly classified as deterministic and probabilistic models. The deterministic model provides a “yes/no” response to the question of whether or not a site will liquefy. However, Performance-Based Earthquake Engineering (PBEE) requires an estimate of the probability of liquefaction (PL) which is a quantitative and continuous measure of the severity of liquefaction. Probabilistic models are better suited for PBEE but …
Application Of Concave-Up P-Y Elements In Static Analysis Of Piles In Laterally Spreading Ground,
2010
University of California, Los Angeles, CA
Application Of Concave-Up P-Y Elements In Static Analysis Of Piles In Laterally Spreading Ground, Pirooz Kashighandi, Scott J. Brandenberg
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Concave-up p-y behavior in liquefied sand has been observed by many researchers due to the dilatant tendency of sand that is dense of its critical state being suppressed in undrained loading. However, static analysis method often scale down the concave-down p-y curves that characterize drained loading, thereby missing the potentially important influence of concave-up behavior on pile response. For lateral spreading problems, large shear strains are typically assigned to the liquefied layer, which presupposes that the liquefied sand is soft and weak. This assumption is incompatible with the strengthening, stiffening concave-up p-y material. This paper presents a static lateral spreading …
Displacement Ductility Capacity Of Fixed-Head Piles,
2010
National Center for Research on Earthquake Engineering, Taiwan
Displacement Ductility Capacity Of Fixed-Head Piles, Jiunn-Shyang Chiou, Cheng-Hsing Chen
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This study performs a parametric study on the displacement ductility capacity of a fixed-head pile. The Winkler-beam model is employed, in which both the soil nonlinearity and pile nonlinearity are adequately considered. In this parametric study, the pile is regarded as a limited ductility structure which conditionally allows the pile deformation to enter the plastic range during loadings. The analysis variables include the axial force, the pile diameter, the longitudinal reinforcement ratio, and the soil stiffness. The relationships of the displacement ductility capacity of the pile to the curvature ductility capacity and to the over-strength ratio of the pile section …
Liquefaction Potential Evaluation Based On Site Classes – A Performance Based Approach,
2010
Indian Institute of Science, India
Liquefaction Potential Evaluation Based On Site Classes – A Performance Based Approach, T. G. Sitharam, K. S. Vipin
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Lots of research work is being carried out in evaluating the liquefaction susceptibility. The main objectives of these studies are to identify the regions which are vulnerable to liquefaction. In the present study, an attempt has been made to predict the liquefaction susceptibility based on corrected SPT values required to prevent the liquefaction for given return periods. The evaluation of liquefaction susceptibility requires the calculation of two parameters, seismic loading and the soil resistance. In most of the studies, the seismic loading will be evaluated based on probabilistic methods and the evaluation of soil resistance will be done based on …
Monotonic And Cyclic Behavior Of Helical Screw Piles Under Axial And Lateral Loading,
2010
Ministry of Transportation & Infrastructure, Canada
Monotonic And Cyclic Behavior Of Helical Screw Piles Under Axial And Lateral Loading, Yasser Abdelghany, M. Hesham El Naggar
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The main objectives of this research paper are to: investigate the monotonic and cyclic behavior of helical pile foundation systems, develop new helical screw systems suitable for seismic retrofitting of existing foundations and new structures. The proposed new pile configurations proposed include: fiber reinforced polymer grouted helical screw piles (FRP-G-HSP); and reinforced grouted helical screw piles (RG-HSP) with steel fibers added to the grout. The research methodology involved conducting more than one hundred full scale field load tests on twenty three helical screw piles installed in cohesive soil and subjected to axial and lateral monotonic and cyclic loading in which …
Calibrated 3d Computational Modeling Of Soil-Structure Systems And Liquefaction Scenarios,
2010
University of California San Diego, La Jolla, CA
Calibrated 3d Computational Modeling Of Soil-Structure Systems And Liquefaction Scenarios, Ahmed Elgamal
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Three-dimensional (3D) computational simulation is increasingly allowing for insights into the mechanics of seismic soil-structure system response. Calibration is being facilitated by field, full-scale, and centrifuge model laboratory data. Computational algorithms and scenario-specific graphical user-interfaces are gradually permitting the routine adoption of such geometrically realistic simulation environments. This paper presents an overview of salient recent 3D soil-foundation-structure earthquake response simulations. Developments related to graphical user-interfaces (OpenSeesPL, http://cyclic.ucsd.edu/openseespl) are summarized, demonstrating the current and evolving capabilities towards performance-based earthquake engineering (PBEE). From an OpenSeesPL-generated lateral push-over analysis of a large pile-group, it is shown that corner piles may shoulder a significantly …
Case Histories And Energy-Based Evaluation On Travel Distance Of Slope Failures During Recent Earthquakes,
2010
Chuo University, Japan
Case Histories And Energy-Based Evaluation On Travel Distance Of Slope Failures During Recent Earthquakes, Takaji Kokusho, Tomohiro Ishizawa
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
An energy approach evaluating travel distance of debris in slope failures is proposed here, in which earthquake energy and gravitational potential energy are dissipated in flow deformations. Shake table model tests of dry sand slopes are carried out in which the earthquake energy dissipated in slope failure can be successfully quantified. The model tests indicate that measured slope displacements can be reliably evaluated by the proposed energy approach based on a rigid block model if an appropriate friction coefficient of the slope is specified. The energy approach is then applied to a number of slopes failed during recent earthquake in …
Estimation Of Displacement Demand For Seismic Design Of Bridges With Rocking Shallow Foundations,
2010
University of California, Davis, C
Estimation Of Displacement Demand For Seismic Design Of Bridges With Rocking Shallow Foundations, Bruce L. Kutter, Lijun Deng, Sashi Kunnath
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Rocking foundations provide many desirable characteristics for a yielding dynamic system; they are economical, they provide a ductile (energy dissipating) moment limiting hinge, and they have a natural re-centering tendency. In order to take advantage of these characteristics in routine practice, simplified design procedures for bridge systems with rocking foundations are required. Two performance targets for deterministic seismic bridge design are: collapse should not occur during the “Maximum Credible Earthquake”, and, the serviceability of the bridge should not be compromised during smaller events that are expected during the lifetime of the structure (Functional Evaluation Earthquakes). The crux of the design …
Integrated Earthquake Resistant Design Of Structure-Foundation Systems,
2010
University of Auckland, New Zealand
Integrated Earthquake Resistant Design Of Structure-Foundation Systems, Michael J. Pender
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In this paper the case is made for an integrated approach to the earthquake resistant design of structure-foundation systems. Emphasis is placed on the need to analyse the response of a system that has the foundation and structure modelled with comparable levels of sophistication. The paper gives examples which illustrate what can be achieved with simplified models that represent the essence of the structural and foundation behaviour. However, to achieve a truly integrated structure-foundation design the investigation of the soil in which the foundation will be constructed needs to receive effort comparable to that expended in modelling the structurefoundation system. …
Modeling The Observed Site Response From Istanbul Strong Motion Network,
2010
Bogaziçi University, Turkey
Modeling The Observed Site Response From Istanbul Strong Motion Network, Atilla Ansal, Gökçe Tönük, Aslı Kurtuluş, Mustafa Erdik, Stefano Parolai
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
An extensive site investigation study was carried out in the European side of Istanbul as part of the large-scale microzonation project for the Istanbul Metropolitan Municipality. 2912 borings mostly down to 30m depth with approximately 250m spacing were conducted within an area of 182 sqkm to investigate local site conditions. 55 stations of the Istanbul Rapid Response Network and Ataköy vertical array are located in this area. There have been few small earthquakes in the recent years with local magnitude slightly over M=4. One of these earthquakes took place on 12/3/2008 in Yalova with local magnitude of M=4.8. Vertical array …
Performance-Based Design Of Geotechnical Structures: Recent Advances,
2010
Kyoto University, Japan
Performance-Based Design Of Geotechnical Structures: Recent Advances, Susumu Iai, Tetsuo Tobita
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The paper presents an overview of recent advances in earthquake geotechnical engineering with respect to the seismic design of geotechnical structures. The modern principles in seismic design are described along the framework of performance-based design as adopted in the International Standard (ISO23469). With the growing awareness of the need to understand the effect of non-linearity in soils and soil-structure interaction, the paper discusses the highly non-linear response of ground during strong earthquake motions with a peak ground acceleration exceeding 1g, and the highly non-linear behavior of soil-pile interaction, including soil-pile separation. The modern principles in seismic design described in this …
Pushover And Inelastic-Seismic Response Of Shallow Foundations Supporting A Slender Structure,
2010
National Technical University of Athens, Greece
Pushover And Inelastic-Seismic Response Of Shallow Foundations Supporting A Slender Structure, George Gazetas, Andriani I. Panagiotidou, Nikos Gerolymos
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The interaction between a surface foundation and the supporting inelastic soil under the action of monotonic, cyclic, and seismic loading is studied numerically. The foundation supports an elastic tall system, the horizontal loading of which induces primarily an overturning moment and secondarily a shear force. Starting from linear elastic behavior, the footing eventually uplifts from the soil, provoking strong inelastic soil response culminating in development of a bearing–capacity failure mechanism and progressive settlement. The substantial lateral displacement of the pier mass induces an additional aggravating moment due to P–δ effect. The paper outlines the moment–rotation–settlement relations under monotonic loading at …
Understanding Seismic Embankment Dam Behavior Through Case Histories,
2010
University of Coimbra, Portugal/ National Laboratory of Civil Engineering (LNEC)
Understanding Seismic Embankment Dam Behavior Through Case Histories, Pedro Simão Sêco E Pinto
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
From the lessons learned from past earthquakes, it is noticed that modern embankment dams withstand the design earthquake without significant damages. In spite of this scenario it is important to prevent the occurrence of incidents and accidents of embankment dams during the earthquakes and so a deep understanding of the triggering factors is important. Well documents case histories from many parts of the world related embankment dams behaviour during recent earthquakes were carefully selected and are discussed. Based in the governed factors attention is given to the requirements for materials characterization, modelling, analysis, monitoring and safety evaluation. Ageing effects and …
Architecture As An Expression Of Identity: Abbas Hilmi Ii And The Neo-Mamluk Style,
2010
School of Oriental and African Studies, Germany
Architecture As An Expression Of Identity: Abbas Hilmi Ii And The Neo-Mamluk Style, Nadania Idriss
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper examines the religious architecture that was built at the end of the nineteenth, beginning of the twentieth century, during the rule of Abbas Hilmi II (1892-1914). The architecture is examined in light of the political and cultural climate of the time period. European influences brought new tastes for building styles, and the Neo-Mamluk became popularized for mosque architecture.
Comparison Between Clean Sand Liquefaction Charts Based On Penetration Resistance And Shear Wave Velocity,
2010
Rensselaer Polytechnic Institute, Troy, NY
Comparison Between Clean Sand Liquefaction Charts Based On Penetration Resistance And Shear Wave Velocity, Ricardo Dobry
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A comparison is conducted between clean sand liquefaction charts based, respectively, on normalized point penetration resistance in CPT static cone tests (qc1N) and shear wave velocity (Vs1). Examination of the shape of these field-calibrated curves, review of the factors influencing liquefaction resistance in the laboratory, field correlations between qc1N and Vs1, and field and laboratory evidence related to some of the factors influencing cone penetration resistance and shear wave velocity in sands, are all used in the discussion. It is concluded that the difference between the shapes of the two charts at the …
Comparison Of Energies Required To Densify Liquefiable Soil,
2010
Virginia Tech, Blacksburg, VA
Comparison Of Energies Required To Densify Liquefiable Soil, Russell A. Green, James K. Mitchell
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The objective of the study presented herein is to compare the energy required to densify loose, liquefiable sand by various techniques and the energy required to liquefy the soil by earthquake shaking. The states-of-practice for performing remedial ground densification and evaluating earthquake liquefaction potential of loose saturated sands have evolved relatively independently of each other. This is in spite of the fact that the inducement of liquefaction is typically requisite for remedial ground densification of sands. Using the energy required to induce liquefaction as a common metric, simple calculations are presented for estimating the mechanical energy required to densify a …
I.M. Idriss: A Pioneer In Geotechnical Earthquake Engineering,
2010
University of British Columbia, Canada
I.M. Idriss: A Pioneer In Geotechnical Earthquake Engineering, W. D. Liam Finn
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
No abstract provided.
Performances Of Rockfill Dams During Recent Large Earthquakes,
2010
Chuo University, Japan
Performances Of Rockfill Dams During Recent Large Earthquakes, Kenji Ishihara
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
There has been increasingly high intensity of acceleration ever recorded during earthquakes in recent times. In consistence with this trend several characteristics have been unearthed regarding performances of rockfill dams. With due considerations to these, damage features of high rockfill dams during recent earthqukes in Japan and China are briefly introduced herein, together with those previously reported. As an indicator of overall distress to the dams, the crest settlement was taken up and it was shown that the settlement tends to increase up to about 1.5% of the height of the dam with increasing acceleration during earthquakes.
Sand Plasticity Model For Nonlinear Seismic Deformation Analyses,
2010
University of California, Davis, CA
Sand Plasticity Model For Nonlinear Seismic Deformation Analyses, Ross W. Boulanger
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A sand plasticity model for nonlinear seismic deformation analyses is presented. The model follows the basic framework of the stressratio controlled, critical state compatible, bounding surface plasticity model for sand presented by Dafalias and Manzari (2004). Modifications to the model were implemented to improve its ability to approximate the stress-strain responses important to geotechnical earthquake engineering applications; in essence, the model was calibrated at the equation level to provide for better approximation of the trends observed across a common set of experimentally- and case history-based design correlations. An overview of the model formulation and example simulations of element loading tests …
Criterions, Prediction And Prevention Of Loess Liquefaction,
2010
Lanzhou Institute of Seismology, China Earthquake Administration, China
Criterions, Prediction And Prevention Of Loess Liquefaction, Lanmin Wang, Zhongxia Yuan, Haimei Sun, Jin Deng
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Although loess liquefaction is not very common during earthquakes in Northwest of China, it is disastrous if it happens. Both study and valid evidence from Haiyuan 8.5 Earthquake in 1920 and Tajikistan 5.9 Earthquake in 1989 have proved that loess liquefaction could be very disastrous under certain conditions. In this paper, the criterions of loess liquefaction are discussed to show that unlike typical liquefaction of sand, loess which falls into the category of both silt clay and clayey silt has unique characteristics during liquefaction test. To predict liquefaction of loess, a simple method based on laboratory test and field evidences …
