Simplified Theoretical Analysis Of The Seismic Response Of Artificially Compacted Gravels,
2010
University of Cassino, Italy
Simplified Theoretical Analysis Of The Seismic Response Of Artificially Compacted Gravels, Giuseppe Modoni, Anna Gazzellone
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Despite extensive use of gravely materials for the construction of big earthworks, theoretical prediction of their seismic response is often based on very simple schemes, unable to reproduce most of the important features observed at sample scales. Theoretical models capable of simulating the effects of artificial compaction on the stress-strain response of these soils under complex static and dynamic loading conditions would be particularly useful for designing more cost effective solutions in the construction of large embankments. This paper is aimed to fill this gap by reporting the results of a simplified theoretical study on the seismic response of an …
The Effect Of Nonplastic Silt Gradation On The Liquefaction Behavior Of Sand,
2010
Oregon State University, Corvallis, OR
The Effect Of Nonplastic Silt Gradation On The Liquefaction Behavior Of Sand, Mehmet Murat Monkul, Jerry A. Yamamuro
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Various researchers have published results regarding the effect of non plastic silts on the liquefaction behavior of sands. Some concluded that increasing fines content decrease the liquefaction potential, whereas others observed the opposite. Some of those discrepancies might be explained via various factors such as different confining stresses, different depositional methods, different consolidation histories and possibly different comparison bases (i.e. void ratio, intergranular void ratio, relative density). New experimental results from monotonic undrained triaxial compression tests performed on Nevada Sand-A mixed with different silts indicate that liquefaction behavior is also significantly influenced by the gradation of the fines.
Field And Laboratory Tests In Seman Deposits,
2010
Polytechnic University of Tirana, Albania
Field And Laboratory Tests In Seman Deposits, Luljeta Bozo, Skender Allkja, Lorena Harizaj
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The construction of the big energetic park near the spilling of the river needed a geotechnical study to be performed by thoroughly investigations of the sand’s deposits. We would like to present in these papers all the field investigations, laboratory tests and geotechnical study carried out by “ALTEA&GEOSTUDIO2000” laboratory in order to identify the behavior of soils under static and seismic loads. It is possible to create some geotechnical models based on this study and to determine their behavior under static and seismic conditions.
Development Of Database Of Cyclic Soil Properties From 94 Tests On 47 Soils,
2010
University of Rijeka, Croatia
Development Of Database Of Cyclic Soil Properties From 94 Tests On 47 Soils, Leo Matesic, Chu-Chung Hsu, Marco D'Elia, Mladen Vucetic
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Cyclic properties of 47 soils were tested in several investigations between 1994 and 2004 in the standard Norwegian Geotechnical Institute (NGI) direct simple shear (DSS) device and an NGI-type dual-specimen DSS (DSDSS) device for small strain testing. In each investigation many cycles of different amplitude, c, and frequency, f, were applied at different levels of vertical stress, v, and overconsolidation ratio, OCR. In DSDSS device many consecutive series of different small c=0.0003-0.01% were applied on the same specimens without changing their structure, because at such small c cyclic shearing is nondestructive. Consequently, the vast amounts of small-strain data were generated. …
An Insight To The Effect Of Initial Static Shear Stress On The Liquefaction Of Sands,
2010
Sharif University of Technology, Iran
An Insight To The Effect Of Initial Static Shear Stress On The Liquefaction Of Sands, S. Mohsen Haeri, Mehdi Pouragha
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The effect of initial static shear stress on cyclic behavior of sands has been the concern of many researchers for more than five decades. This study includes the results of a set of cyclic simple shear tests carried out on a uniform sand with relative densities of 20%, 40%, and 60%, under three different initial normal stresses of 50, 150, and 250 kPa. All tests were performed under constant volume condition. Results show that the behavior of sands due to initial static shear stress, is controlled by two contradictive elements: first one relates to the increasing dynamic shear modulus due …
Resonant-Frequency Method Of Soil Damping Characteristics Determination,
2010
Gersevanov NIIOSP, Russia
Resonant-Frequency Method Of Soil Damping Characteristics Determination, Leonid Stavnitser, Galina Nikitaeva
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The resonant-frequency method of determining the absorption factors characterizing the soil damping properties has been developed for implementation of software programs on computation of dynamic interaction of foundation based constructions. This method is based on processing of amplitude-frequency characteristics of soil samples obtained from the vibro-dynamical tests carried out on the specially constructed installation equipped with the vibro-recording instruments. A set of experiments was performed with sandy and clayey soils at difference humidity, density and stratification depth, based on investigation of forced oscillations of these samples and further processing of the resonance curves within the frames of presentation of the …
Assessing Cross Anisotropy Of Small-Strain Stiffness Using The Resonant Column Apparatus,
2010
University of Southampton, U.K.
Assessing Cross Anisotropy Of Small-Strain Stiffness Using The Resonant Column Apparatus, Amit K. Sultaniya, Christopher R. I. Clayton, Jeffrey A. Priest, Khairul Anuar Mohd. Nayan, Mohd. Raihan Taha
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Almost all soils exhibit cross-anisotropic stiffness to some extent. However, measuring the cross anisotropic properties of soils is difficult because of the need to determine the 3 independent stiffness parameters Eν, Eh, Gνh, and the associated Poisson’s ratios, nνh and nhh. Current techniques that are employed, for example using bender elements or field geophysics, are not always reliable, whilst preparing specimens in different orientations and subsequent testing using standard laboratory techniques has practical constraints. The resonant column is a laboratory apparatus that has been extensively used to measure the torsional stiffness …
Undrained Response Of Clean And Silty Sands,
2010
University of Western Australia, Australia
Undrained Response Of Clean And Silty Sands, Tejas G. Murthy, Monica Prezzi, Rodrigo Salgado, Dimitrios Loukidis
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
An experimental investigation was undertaken to study the effect of small amounts nonplastic fines on the undrained shear response of sands. Mixtures of Ottawa sand containing 0, 5, 10 and 15% nonplastic silts were studied in a triaxial set up under undrained conditions. The response of the mixtures was summarized based on four characteristic states observed during undrained shearing. These states are the flow liquefaction state, the phase transformation state, the quasi steady state and the critical state. The effects of silt content and initial fabric on relationships describing these characteristic states are highlighted in this paper.
Vibrodriving Prediction Models Vs. Experimental Results,
2010
Belgium Building Research Institute (BBRI), Belgium
Vibrodriving Prediction Models Vs. Experimental Results, Valérie Whenham, Alain Holeyman
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper reviews and discusses methods currently available to assess the vibro-driveability of piles based on a comparison between calculations and experimental observations. The experimental results come from databases collected in Belgium and in The Netherlands, as well as from full scale tests campaigns conducted in Belgium and in France. Discrepancies between modeling assumptions and actual observations are highlighted, and some suggestions are made to improve the performance of design methods.
Method To Reduce Variability Of S-Wave Profiles In Seismic Cone Penetration Tests,
2010
Belgian Nuclear Research Centre/ Vrije Universiteit Brussel, Belgium
Method To Reduce Variability Of S-Wave Profiles In Seismic Cone Penetration Tests, Lou Areias
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The pseudo method used to calculate shear wave velocity (Vs) in seismic cone penetration (SCP) tests often generates high variability of Vs values at shallow depths. This occurs when travel paths are small and signal variability large to allow accurate arrival time differentiation between successive signals. The offset distance between the source and receivers has the largest influence on signal variability. A method described in this paper shows good results in reducing Vs variability of SCP tests during post processing. The method consists of increasing the sampling interval to calculate Vs and then regrouping the data …
A New Method For Evaluating Spatial Variability Of Soil Strains Developed During Earthquakes Based On Electrical Resistivity Concepts Using Green’S Function,
2010
AMEC Geomatrix, Inc., Oakland, CA
A New Method For Evaluating Spatial Variability Of Soil Strains Developed During Earthquakes Based On Electrical Resistivity Concepts Using Green’S Function, Zhihua Li
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A new method for evaluating spatial variability of soil strains during earthquakes is developed. The idea is based on electrical resisitivity concepts. By solving the classic Maxwell’s equations applying Green’s function for the boundary conditions, we obtained a closed form solution relating the electric potential measurements to the soil’s displacements during earthquakes. The displacement information can be further used to obtain soil strains. In centrifuge models, the displacement measurements using an electrode switching system have been demonstrated to have spatial and temporal resolutions of 1 mm and 1 ms. Based on the high resolution of the displacement that is obtainable, …
Applicability Test Of Soil Improvement Using Micro-Bubbles Against Soil Liquefaction,
2010
Sato Kogyo Co., Ltd., Japan
Applicability Test Of Soil Improvement Using Micro-Bubbles Against Soil Liquefaction, Koichi Nagao, Naoaki Suemasa, Tatsuo Akashi, Mikio Futaki
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The purpose of this paper is to demonstrate the effectiveness of micro-bubble water injection method against soil liquefaction based on the result of seismic vibration test using large scale flexible shaking box. It is well known that soil resistance to liquefaction increases as the degree of saturation of the soil decreases, but the practical method to decrease the saturation of the soil has not been invented. The authors solved this problem by new method of injecting water containing micro-air bubbles into the ground. The method has an advantage which not only simple and cost-effective but also friendly to environment. We …
Shake Table Testing To Quantify Seismic Soil-Structure-Interaction Of Underground Structures,
2010
California Polytechnic State University, San Luis Obispo, CA
Shake Table Testing To Quantify Seismic Soil-Structure-Interaction Of Underground Structures, Robb Eric S. Moss, Vic Crosariol, Steven Kuo
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This research uses shake table testing of scale soil-structure models to mimic the coupled seismic response of underground structures and surrounding/supporting soil (termed soil-structural-interaction or SSI). Currently the seismic design of subways and other critical underground infrastructure rely on little to no empirical data for calibrating numerical simulations. This research is working towards filling that empirical data gap. The research is composed of two phases, the first a validation of the free-field response of a flexible wall barrel filled with model soil, the second a test to measure the “racking” deformations induced in a model subway cross-section embedded in the …
Dynamic Behavior Of An Elastic Beam On A Winkler Foundation Under A Moving Load,
2010
Istanbul Technical University, Turkey
Dynamic Behavior Of An Elastic Beam On A Winkler Foundation Under A Moving Load, Abdul Hayir
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The purpose of this study is to investigate the response of an elastic beam on a Winkler foundation under a moving load. The load is assumed as a moving harmonic load and the beam is considered as an infinite Bernoulli-Euler beam with constant cross-section. The approach of Winkler foundation for the elastic foundation is very common in the practical applications although it does not accurately represent the continuous characteristic of the foundations. In this model the interaction between the vertical springs is only considered. In the solutions of the problem, the double Fourier Transform is applied and for its invention …
Geotechnical Seismic Isolation By Scrap Tire-Soil Mixtures,
2010
University of Hong Kong, Hong Kong
Geotechnical Seismic Isolation By Scrap Tire-Soil Mixtures, Hing-Ho Tsang, Nelson T. K. Lam, Saman Yaghmaei-Sabegh, M. Neaz Sheikh, Buddhima Indraratna
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The stockpiling of scrap tires is a significant threat to our environment and has been a hot topic amongst the engineering community which has been looking for long term viable solutions to the recycling and reuse of rubber tires. This paper proposes a new method of utilizing scrap tires for applications in infrastructure protection forming part of the solution strategy. The method involves mixing scrap tire particles with soil materials and placing the mixtures around civil engineering systems, for vibration absorption. The inexpensive nature of the proposed method can be of great benefits to developing countries where there are affordability …
Large Variation In Pga Due To Presence Of Heterogeneities In The Surface Soil,
2010
Earthquake Engineering Research Centre, IIIT Hyderabad, India
Large Variation In Pga Due To Presence Of Heterogeneities In The Surface Soil, Mohammad Ahmed Hussain, Ramancharla Pradeep Kumar
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In the proximity of an active fault, spatial variation of peak ground motion is significantly affected by the faulting mechanism. It has been observed that near fault ground motions consists of different characteristics compared to the far fault ground motions. Near fault records, in the distance range of less than 100 m from the faults are not available except for few cases. Therefore numerical simulation of ground motions for such near-fault situations is necessary. There is a need to enhance our understanding of the possible potential hazard that can be caused due to the future rupture activity by understanding the …
Mechanical And Acoustical Vibrations Of A Building Generated By Weaving Looms,
2010
Romanian National Center for Earthquake Engineering and Vibrations (R.N.C.E.E.V.) within T.U.C.E., Romania
Mechanical And Acoustical Vibrations Of A Building Generated By Weaving Looms, Ion Vlad
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Dynamic excitations and the resulting stresses in a weaving mill can affect its functioning in many different ways. Possible consequences of service vibrations include emission of acoustic waves, reduction of product quality, damage of non-structural elements (especially partition walls and cladding) and the disturbance of the activity in buildings placed in close vicinity. It is difficult to identify the influence of the vibrations on the production, on the weaving shed and on the neighborhoods. In 2004, an Italian company has rented in Romania 6000 square meters in a huge, one level industrial building, in order to lay out a weaving …
3-D Modeling Of Shear-Wave Velocity For Numerical Green’S Function In Near-Field Ground Motion Simulation,
2010
Harbin Institute of Technology, China
3-D Modeling Of Shear-Wave Velocity For Numerical Green’S Function In Near-Field Ground Motion Simulation, Xiaodan Sun, Xiaxin Tao, Lijun Yin, Dongli Zhang
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Numerical Green’s function is effective for simulating low-frequency ground motions in the near field, in which the whole computing region is divided into a homogenous zone including the source and an inhomogeneous zone (named overburden layer) from the ground surface to a certain depth. In this paper, a procedure to build a 3-D model that properly describes the shear-wave velocity structure of overburden layer and the topography of ground surface was presented. In this procedure, the overburden layer is discretized into finite elements based on the topography of ground surface and buried rock surface; shear-wave velocity data from inversion, surveying …
Aggravation Of The Peak Seismic Acceleration In The Vicinity Of 2d Hills, Canyons And Slopes,
2010
University of Thessaly, Greece
Aggravation Of The Peak Seismic Acceleration In The Vicinity Of 2d Hills, Canyons And Slopes, Achilleas G. Papadimitriou, Yannis Chaloulos
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper studies the topographic aggravation of the peak seismic acceleration in the horizontal and vertical directions for various cases of 2D uniform surface geometries: hills, canyons and slopes. The study is based on a large number of 2D wave propagation analyses for uniform soil conditions performed with the finite-difference method. All analyses were visco-elastic, assumed vertically impinging harmonic SV waves and studied parametrically the effects of the slope inclination i, the dimensionless height H/λ of the topographic feature (where H is the height and λ is the predominant S wavelength) and of the width B of the canyon base …
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. …
