Investigation Of Shear Strain Amplitude Induced By Railroad Traffic In Soils,
2010
Engineering office GEPRO Ingenieurgesellschaft GmbH, Germany
Investigation Of Shear Strain Amplitude Induced By Railroad Traffic In Soils, Dirk Wegener, Ivo Herle
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Shear strain amplitude γ is an important quantity in dynamic soil analysis. Usually, a reduction of soil stiffness with increasing shear strain amplitude is observed in laboratory tests. An appropriate invariant of shear strain can be defined which is comparable with shear strains measured in laboratory tests. Usually, shear wave velocity cs is determined from field or laboratory tests and the particle velocity v is obtained from vibration measurements. Afterwards, the shear strain amplitude γ is often estimated from the equation γ = ν / cs, which can be derived for the case of one dimensional wave propagation. …
Stress- And Strain-Controlled Undrained Cyclic Triaxial Tests On A Fine Sand For A High-Cycle Accumulation Model,
2010
University of Karlsruhe, Germany
Stress- And Strain-Controlled Undrained Cyclic Triaxial Tests On A Fine Sand For A High-Cycle Accumulation Model, Torsten Wichtmann, Benjamin Rojas, Andrzej Niemunis, Theodor Triantafyllidis
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The paper presents a discussion of the isotropic elastic stiffness E in the high-cycle accumulation (HCA) model proposed by Niemunis et al. (2005). The model may be used to predict permanent deformations or excess pore water pressures in non-cohesive soils due to cyclic loading. The stress-dependent bulk modulus K was determined from pairs of drained and undrained cyclic triaxial tests on a fine sand with constant stress amplitude and with similar initial conditions. K was found in good agreement with an earlier study on a medium coarse sand where a correction for membrane penetration effects had to be applied. Undrained …
Vibrations Due To Dynamic Compaction,
2010
İstanbul Technical University, Turkey
Vibrations Due To Dynamic Compaction, M. Ayşen Lav, Ercan Yüksel, Faruk Karadoğan
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Ground vibrations due to dynamic compaction (DC), at a harbor site were measured to investigate whether the magnitude of vibrations were unacceptably strong to cause any damage to or increase existing damage on the surrounding structures experienced August 17, 1999 Kocaeli, Gölcük earthquake (M~7.4). The site is located in city of Kocaeli at the seaside of The Port of Derince. It was a reclaimed land formed with Hereke limestones. The measured data included vibrations induced by the tamping energy of DC both at the vicinity of nearby structures and within the DC site. The site was surrounded by a shallow …
Viscous Damping For Time Domain Finite Element Analysis,
2010
University of Colorado Denver, Denver, CO
Viscous Damping For Time Domain Finite Element Analysis, Nien-Yin Chang, Hien Manh Nghiem
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Earthquake waves propagate mainly in rock mass from hypocenter to the bedrock directly underneath a monitoring station. Then, it propagates as shear waves from the bedrock to a geophone, where the surface motion is measured. For a deposit with uniform soil layers of horizontal interfaces, one-dimensional finite element analysis can be performed to analyze the dynamic responses of a horizontal soil deposit. In an ideal dynamic soil-structure interaction analysis, seismic waves are propagated from the bedrock through soils and foundations, and then to structure. Thus, it is necessary to obtain the bedrock motion from a measured surface motion registered in …
A Validation Study Of A Seismically Induced Ground Strain Model Using Strong Motion Array Data,
2010
University of California, Los Angeles, CA
A Validation Study Of A Seismically Induced Ground Strain Model Using Strong Motion Array Data, Timothy D. Ancheta, Jonathan P. Stewart
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This study concerns ground strains that result from spatially variable ground motions unrelated to ground failure. Prior empirical work shows a dependence of peak ground strain (PGS) on peak ground displacement (PGD) but is applicable only for weak motions (PGD < 10 cm). Prior semi-empirical work, in which strains were evaluated from simulated ground motions that preserve the coherency, Fourier amplitude variability and wave passage observed in array recordings, found a similar dependence of PGS on PGD but also a significant dependence on separation distance of observation points. Here we describe a procedure to calculate PGS between pairs of stations in an array to test the separation dependence of PGS. The Lotung LSST array was selected due to its closely spaced stations (6 to 85 m) and large number of recordings. The PGS estimated from station pairs from 11 events illustrate that the distance dependence of PGS is statistically significant, with PGS increasing as separation distance decreases.
Effect Of Topographical Irregularities On Seismic Earthquake Response Of Construction Site – 2d Numerical Analysis Of Trapezoidal Valley Under Real Motion,
2010
Islamic Azad University, Iran
Effect Of Topographical Irregularities On Seismic Earthquake Response Of Construction Site – 2d Numerical Analysis Of Trapezoidal Valley Under Real Motion, Hamed Khodadadi Tirkolaei, Morteza Jiryaei Sharahi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Documented observation of destruction distribution after seismic events suggest to topography effects on earthquake intensity. But there exist very few –if any- well documented case studies where topography effects are illustrated for strong ground motion. This is due to complex nature of seismic scattered wave by topographical structures to medium. Although some empirical correlations, obtained from statistical analyses, were proposed in different studies to consider this issue, but these correlations also may not be applicable in general or may be overestimation of what happen in reality. These difficulties and disadvantages can only be solved accurately, economically and under realistic conditions …
Evaluation Of Iranian Code No.2800 For Seismic Resistant Design Of Near Source Buildings Based On Real Record Of Iran,
2010
University of Kurdistan, Iran
Evaluation Of Iranian Code No.2800 For Seismic Resistant Design Of Near Source Buildings Based On Real Record Of Iran, Kaveh Andisheh, Gholamreza Ghodrati Amiri
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In this paper characteristics of near-field earthquakes and difference of ground motion response key parameters in these earthquakes, based on real records of Iran are presented and efficiency of Iranian seismic building code for design of buildings subjected to near-field earthquakes is evaluated. The equivalent static method to calculate the lateral earthquake force exerted on buildings, is common and extensively used. Iranian code of practice for seismic resistant design of buildings, Standard No.2800-05, uses V= (ABI /R)*W relationship to calculate this lateral force. Where A (=design basis acceleration over the bedrock) and B (=the amplification factor) are related to earthquake, …
Evaluation Of Seismic Response Of A Site Class F Site Using Equivalent Linear And Nonlinear Computer Codes,
2010
GeoEngineers, Inc., Redmond, WA
Evaluation Of Seismic Response Of A Site Class F Site Using Equivalent Linear And Nonlinear Computer Codes, King H. Chin, Braydan Duree, Whitney Trent, Gustavo Ordonez
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Evaluation of seismic site response and development of site-specific surface response spectra has evolved in recent years through the use of both equivalent linear (EQL) and nonlinear (NL) computer codes. Before the nonlinear computer codes become popular among practitioners, equivalent linear site response analysis programs were used to develop site-specific design spectra for both soft and stiff sites. Nonlinear site response analysis is now used more routinely for projects planned on Site Class F sites. This paper presents the results of seismic response analyses completed for a Site Class F site at Grays Harbor, Washington. Both the equivalent linear (SHAKE2000) …
Example For Risk Estimation Of Fault Appearance Under The Place Of Designed Skyscraper In Sofia,
2010
University of Transport, Bulgaria
Example For Risk Estimation Of Fault Appearance Under The Place Of Designed Skyscraper In Sofia, Chavdar V. Kolev, Martina G. Perikliyska
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
There was an interesting discussion during the designing stage of one of the future skyscrapers in Sofia – is the soil basement reliable enough if it is true the hypotheses for a fold under the construction place? The substantial geotechnical report doesn’t give answers to this question but the geological profiles suggest to us about an appearance of fold. Topographic and historical specifics of the area are supporting the same unsuitable idea. The additional geophysics investigations clearly establish a lack of fold displacements under the place during the Quaternary period. The zone has high seism and an individual seismic ratio …
Experimental And Numerical Study Of Topographic Site Effect On A Hill Near Tehran,
2010
International Institute of Earthquake Engineering and Seismology, Iran
Experimental And Numerical Study Of Topographic Site Effect On A Hill Near Tehran, Mohammad Khandan Bakavoli, Ebrahim Haghshenas
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper compares the experimental study of seismic response of a hill site near Tehran and numerical modeling of the test site using a hybrid finite-boundary element code named HYBRID. Both longitudinal and transversal profiles of the hill have been instrumented using Guralp CMG-6TD seismological stations and some hours of ambient noise were recorded. The H/V ratios for each station were calculated and the amplification patterns and corresponding frequencies of each station have been extracted. Then the two profiles has been modeled numerically and excited by vertically incident SV ricker waves with different fundamental frequencies. The medium is assumed to …
Ground Motion Occurrence Rates For Scenario Spectra,
2010
University of California Davis, Davis, CA
Ground Motion Occurrence Rates For Scenario Spectra, Norman Abrahamson, A. Anil Yunatci
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
It is common practice for probabilistic seismic hazard analysis (PSHA) to use the uniform hazard spectra (UHS) to describe the ground motion. A short-coming of UHS is that it represents an envelope of many different earthquakes that control the hazard at different spectral periods. As an alternative, the UHS can be broken into a suite was developed by Baker and Cornell (2006), in which conditional mean spectra (CMS) are developed that represent realistic earthquake scenarios given a specified spectral acceleration at a single period. Using only the CMS as scenarios is too restrictive and does not provide enough scenarios to …
Model Validation Of Recent Ground Motion Prediction Relations For Shallow Crustal Earthquakes In Active Tectonic Regions,
2010
Tufts University, Medford, MA
Model Validation Of Recent Ground Motion Prediction Relations For Shallow Crustal Earthquakes In Active Tectonic Regions, James Kaklamanos, Laurie G. Baise
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Recent earthquake ground motion prediction relations, such as those developed from the Next Generation Attenuation of Ground Motions (NGA) project in 2008, have established a new baseline for the estimation of ground motion parameters such as peak ground acceleration (PGA), peak ground velocity (PGV), and spectral acceleration (Sa). When these models were published, very little was written about model validation or prediction accuracy. We perform statistical goodness-of-fit analyses to quantitatively compare the predictive abilities of these recent models. The prediction accuracy of the models is compared using several testing subsets of the master database used to develop the NGA models. …
Numerical Analysis Of Trampoline Effect In Extreme Ground Motion,
2010
Kyoto University, Japan
Numerical Analysis Of Trampoline Effect In Extreme Ground Motion, Tetsuo Tobita, Susumu Iai, Tomotaka Iwata
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Very large vertical surface acceleration of nearly four times gravity was measured at a strong motion observation station in Iwate Prefecture during the 2008 Iwate-Miyagi Inland, Japan, earthquake (Mw 6.9). The station is located about 3 km southwest of the epicenter and equipped with three-component accelerometers, installed at both the free surface and the bottom of a 260-m borehole. The wave form of the vertical acceleration shows a clearly asymmetric form with large amplitude in the upward direction. Aoi et al. (2008) reported and qualitatively explained the mechanism of this phenomenon by the analogy of bouncing a piece of …
The Importance Of Creating Value In Seismic Design,
2010
Arup, U.K.
The Importance Of Creating Value In Seismic Design, Barnali Ghosh, Zygmunt Lubkowski, Jack Pappin
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Major earthquakes have resulted in devastating consequences in terms of human and economic loss. In almost all the earthquakes we observe the failure of structures, sometimes due to poor construction but also due to designers not identifying the specific geo-hazards (iIntensity of ground motion, faults, liquefaction, slopes etc) which affect these structures. In many cases these damages could have been avoided if the original design had correctly identified the geohazards at the site and incorporated the philosophy of performance based design. In this paper several examples will be presented where the different stages of risk assessment will be identified and …
Site Amplification Studies For Npp Sites In Switzerland Within The Project Pegasos And Prp,
2010
Studer Engineering, Switzerland
Site Amplification Studies For Npp Sites In Switzerland Within The Project Pegasos And Prp, Jost A. Studer
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Based on a request by ENSI (Nuclear Regulatory Authority of Switzerland) to update the existing probabilistic earthquake hazard studies, Swissnuclear, the association of the nuclear power plants in Switzerland, initiated the PEAGASOS Project. The project started in 2001 and finished in 2004. It is for Europe a unique study, which aimed to evaluate uncertainties systematically and comprehensively. It was decided to perform the study on SSHAC-level 4. Level 4, defined by the Senior Seismic Hazard-Committee, is the highest level and was used only once before for the Yucca-Mountain-Project in the USA. In the PEGASOS Project, 21 international experts from Europe …
Machine Foundations And Blast Engineering Vibrations Case Studies,
2010
Technical University of Civil Engineering Bucharest, Romania
Machine Foundations And Blast Engineering Vibrations Case Studies, Ion Vlad
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Vibration can cause either serviceability and malfunctioning problems reducing people’s comfort to an unacceptable level, or safety problems with danger of failure. The belief of the author is that the presentation of some practical cases of machine foundation vibrations will be of interest, beneficial and helpful for many researchers and engineers involved in both theoretical and practical studies. Therefore, the most relevant case studies on vibrations of machine foundation ensembles, encountered in practice in the last ten years of activity, will be presented. In all malfunctioning or excessive vibration cases the technical assessment has started with a complex program of …
Dealing In Practice With Selecting And Modifying Earthquake Ground Motions For Nonlinear Analysis,
2010
Kleinfelder, San Diego, CA
Dealing In Practice With Selecting And Modifying Earthquake Ground Motions For Nonlinear Analysis, Jorge F. Meneses
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Nonlinear earthquake analyzes of structures are increasingly required by building codes and other seismic design regulations. An essential component of these analyses is that the geotechnical engineer has to provide the structural engineer with a set of strong motion time histories, typically three or seven sets containing two orthogonal horizontal components, and one vertical component if needed. The procedure for selecting the seed time histories and modifying them to match the design response spectrum involves several steps including development of seismological criteria, earthquake deaggregation analysis, and spectral matching. This procedure for selecting and modifying earthquake ground motions is explained based …
Practical Seismic Design Considering Non-Linear Soil-Pile-Structure Interaction,
2010
Fluor, Vancouver, Canada
Practical Seismic Design Considering Non-Linear Soil-Pile-Structure Interaction, Y. C. Han, Shin – Tower Wang
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A substructure approach is proposed for the seismic analysis considering the soil-pile-structure interaction. Two software packages are available for practical applications, DYNAN program and SAP 2000 program. The nonlinearity of soil is considered approximately using a boundary zone model with non-reflective interface. The validation of model is confirmed with dynamic tests on piles in the field, and the results for a single pile are used to compare with the predictions in this study. The liquefaction for sand soil layer can be accounted for, and a case of liquefaction is discussed. The seismic response of a vacuum tower structure supported on …
Ground Improvement To Reduce Liquefaction Potential Using Vibrocompaction And Stone Columns,
2010
Southern Illinois University Carbondale, Carbondale, IL
Ground Improvement To Reduce Liquefaction Potential Using Vibrocompaction And Stone Columns, Sanjeev Kumar, Tim Holcomb, Shahram Pezeshk
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
With the rapid pace of industrialization, structures are being designed and constructed in the flood plains of major rivers. In earthquake prone areas, a fundamental issue in the design and construction of structures on saturated sandy soils is weather or not the design earthquake could initiate liquefaction in the form of lateral spreading, sand boils, settlement, or cracking. Many different methods, including vibrocompaction, deep dynamic compaction, compaction piles, geopiers, deep mixing, vibratory probes, displacement/compaction grout, etc., have been used to reduce the liquefaction potential at various sites. Use of vibrocompaction to densify cohesionless soil is becoming more common and cost …
Recent Advances In Predicting Earthquake-Induced Sliding Displacements Of Slopes,
2010
University of Texas at Austin, Austin, TX
Recent Advances In Predicting Earthquake-Induced Sliding Displacements Of Slopes, Ellen M. Rathje, George Antonakos
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper summarizes recent research related to predicting earthquake-induced sliding displacements of earth slopes. Recently developed empirical models for the prediction of sliding displacements for shallow (rigid) failure surfaces are discussed, and comparisons of the different models demonstrate that including peak ground velocity, along with peak ground acceleration, reduces the median displacement prediction and the standard deviation of the prediction. Thus, peak velocity provides important information regarding the level of sliding displacement. A framework is developed such that the recently developed empirical displacement models for rigid sliding can be used for deeper, flexible failure surfaces, where the dynamic response of …
