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2010

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Articles 2221 - 2250 of 5375

Full-Text Articles in Engineering

Resonant Frequency Of Model Footings Resting On Finite Saturated Sand Stratum, H. N. Ramesh, M. T. Prathap Kumar May 2010

Resonant Frequency Of Model Footings Resting On Finite Saturated Sand Stratum, H. N. Ramesh, M. T. Prathap Kumar

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The resonant frequency of the foundation-soil system depends on several factors and nonhomogeniety of soil is one of the important factors that include the effect of saturation. In the present investigation, the effect of saturation and location of rigid concrete base on the resonant frequency of foundation-soil system was determined by conducting vertical vibration test on model footings resting on the surface of finite dry sand stratum as well as on finite saturated sand stratum underlain by rigid concrete base. On the basis of the experimental investigation, it was concluded that the presence of rigid base at shallow depth decreases …

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Shearing Rate Effect On Mechanical Behavior Of Msw Materials, Nader Shariatmadari, Sandro Lemos Machado, Ali Noorzad, Mehran Karimpour Fard, Mohsen Keramati, Seyyed Hossein Jafari Kalarijani May 2010

Shearing Rate Effect On Mechanical Behavior Of Msw Materials, Nader Shariatmadari, Sandro Lemos Machado, Ali Noorzad, Mehran Karimpour Fard, Mohsen Keramati, Seyyed Hossein Jafari Kalarijani

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Recent catastrophic failure in different regions of the world is an indication on the poor level of engineering knowledge on the mechanical behavior of MSW materials which are the main materials in the landfill body. However extensive researches have been made to represent a clear frame work to describe the behavior of these materials but clearly all of these attempts had not been enough. In the region with high seismic activity, mechanical response of MSW materials under quick and dynamic loading condition is one of the issues which should be addressed however there are some evidences concerning the higher resistance …

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Simplified Theoretical Analysis Of The Seismic Response Of Artificially Compacted Gravels, Giuseppe Modoni, Anna Gazzellone May 2010

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 …

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The Effect Of Nonplastic Silt Gradation On The Liquefaction Behavior Of Sand, Mehmet Murat Monkul, Jerry A. Yamamuro May 2010

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.

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Field And Laboratory Tests In Seman Deposits, Luljeta Bozo, Skender Allkja, Lorena Harizaj May 2010

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.

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Development Of Database Of Cyclic Soil Properties From 94 Tests On 47 Soils, Leo Matesic, Chu-Chung Hsu, Marco D'Elia, Mladen Vucetic May 2010

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. …

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An Insight To The Effect Of Initial Static Shear Stress On The Liquefaction Of Sands, S. Mohsen Haeri, Mehdi Pouragha May 2010

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 …

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Resonant-Frequency Method Of Soil Damping Characteristics Determination, Leonid Stavnitser, Galina Nikitaeva May 2010

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 …

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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 May 2010

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 …

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Undrained Response Of Clean And Silty Sands, Tejas G. Murthy, Monica Prezzi, Rodrigo Salgado, Dimitrios Loukidis May 2010

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.

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Vibrodriving Prediction Models Vs. Experimental Results, Valérie Whenham, Alain Holeyman May 2010

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.

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Method To Reduce Variability Of S-Wave Profiles In Seismic Cone Penetration Tests, Lou Areias May 2010

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 …

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A New Method For Evaluating Spatial Variability Of Soil Strains Developed During Earthquakes Based On Electrical Resistivity Concepts Using Green’S Function, Zhihua Li May 2010

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, …

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Applicability Test Of Soil Improvement Using Micro-Bubbles Against Soil Liquefaction, Koichi Nagao, Naoaki Suemasa, Tatsuo Akashi, Mikio Futaki May 2010

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 …

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Shake Table Testing To Quantify Seismic Soil-Structure-Interaction Of Underground Structures, Robb Eric S. Moss, Vic Crosariol, Steven Kuo May 2010

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 …

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Dynamic Behavior Of An Elastic Beam On A Winkler Foundation Under A Moving Load, Abdul Hayir May 2010

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 …

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Geotechnical Seismic Isolation By Scrap Tire-Soil Mixtures, Hing-Ho Tsang, Nelson T. K. Lam, Saman Yaghmaei-Sabegh, M. Neaz Sheikh, Buddhima Indraratna May 2010

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 …

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Large Variation In Pga Due To Presence Of Heterogeneities In The Surface Soil, Mohammad Ahmed Hussain, Ramancharla Pradeep Kumar May 2010

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 …

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Mechanical And Acoustical Vibrations Of A Building Generated By Weaving Looms, Ion Vlad May 2010

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 …

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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 May 2010

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 …

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Aggravation Of The Peak Seismic Acceleration In The Vicinity Of 2d Hills, Canyons And Slopes, Achilleas G. Papadimitriou, Yannis Chaloulos May 2010

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 …

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Model Validation Of Recent Ground Motion Prediction Relations For Shallow Crustal Earthquakes In Active Tectonic Regions, James Kaklamanos, Laurie G. Baise May 2010

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. …

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Numerical Analysis Of Trampoline Effect In Extreme Ground Motion, Tetsuo Tobita, Susumu Iai, Tomotaka Iwata May 2010

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 …

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Uniform Hazard Response Spectra Of Korea Considering Uncertainties In Ground Properties, Dong-Yeop Kwak, Duhee Park, Bang Woong Shin, Kwangkyun Kim May 2010

Uniform Hazard Response Spectra Of Korea Considering Uncertainties In Ground Properties, Dong-Yeop Kwak, Duhee Park, Bang Woong Shin, Kwangkyun Kim

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The seismic site coefficients derived deterministically are often used with ground motion parameters determined by probabilistic seismic hazard analysis in construction of the design response spectrum. There is, therefore, an inherent incompatibility between two approaches. New methods have been developed to resolve this incompatibility by developing probabilistic seismic site coefficients. In such approaches, the uncertainties in the properties of the ground were not systematically accounted for due to lack of measurements of the ground. In this study, an integrated probabilistic seismic hazard analysis which can quantify the nonlinear seismic site effects and account for the uncertainties in soil properties is …

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1d Dynamic Non-Linear Numerical Analysis Of Earth Slopes: The Role Of Soil Ductility And Time-Sensitiveness, Claudio Giulio Di Prisco, Federico Pisanò May 2010

1d Dynamic Non-Linear Numerical Analysis Of Earth Slopes: The Role Of Soil Ductility And Time-Sensitiveness, Claudio Giulio Di Prisco, Federico Pisanò

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The mechanical response of dry granular slopes subjected to dynamic perturbations is tackled from a theoretical/numerical viewpoint. A 1D geometrical/numerical scheme is adopted to analyze infinitely long strata: the dynamic activation of shallow translational failure mechanisms (as well as the displacement performance far from collapse) is analyzed by means of a self-made FEM code. The soil mechanical behavior is described by means of a simplified viscoplastic one-dimensional constitutive model, capable of reproducing both ductile (hardening) and brittle (softening) mechanical responses. The dependence of numerical results on the soil “time-sensitiveness”, as well as the differences between viscoplasticity and standard rate-independent plasticity, …

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Nonlinear Site Effects: Interest Of One Directional - Three Component (1d - 3c) Formulation, Maria Paola Santisi D’Avila, Jean-François Semblat, Ali Gandomzadeh, Fabian Bonilla, Luca Lenti, Salvatore Martino May 2010

Nonlinear Site Effects: Interest Of One Directional - Three Component (1d - 3c) Formulation, Maria Paola Santisi D’Avila, Jean-François Semblat, Ali Gandomzadeh, Fabian Bonilla, Luca Lenti, Salvatore Martino

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Strong ground motions generally lead to both a stiffness reduction and a larger energy dissipation in the soil layers. Thus, in order to study such phenomena, several nonlinear rheologies have been developed in the past. However, one of the main difficulties of using a given rheology is the number of parameters needed to describe the model. In this sense, the multi-surface cyclic plasticity approach, developed by Iwan in 1967 is an interesting choice since the only data needed is the modulus reduction curve. Past studies have implemented this method in one-directional SH wave-propagation (1D-1C). This work, however, aims to study …

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Seismic Site Response Analysis Using Spreadsheets, Geraldo R. Iglesia, James L. Stiady May 2010

Seismic Site Response Analysis Using Spreadsheets, Geraldo R. Iglesia, James L. Stiady

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

A spreadsheet-based framework for quantifying local site response due to seismic excitation is presented in this paper. The main focus here is on equivalent-linear one-dimensional analysis, similar to the computer program SHAKE or its derivative kin, which by far is the most commonly used approach for performing ground response evaluation. Such analysis involves the computation of the response of a semi-infinite horizontally layered deposit overlying a uniform half-space subjected to vertically propagating shear waves. The bulk of the analysis is actually carried out in the frequency domain, which involves operations with complex-algebraic parameters. Widely available spreadsheet software is typically equipped …

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A Study Of Effective Factors On The Behavioural Characteristics Of Clayey Sands, Omid Naeemifar, S. Shahaboddin Yasrobi May 2010

A Study Of Effective Factors On The Behavioural Characteristics Of Clayey Sands, Omid Naeemifar, S. Shahaboddin Yasrobi

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

As in recent years liquefaction phenomena have occurred in sandy soils containing different amounts of clay contents, it was concluded that in addition to silty sands, clayey sands are also vulnerable to liquefaction phenomenon. So, the urge for comprehensive study aroused to cover the issue. In this paper, the effect of clay content and its plasticity properties on behavioural characteristics of clayey sands under various density and confining pressure values have been investigated. To achieve the goal, about a hundred monotonic triaxial tests were performed on remoulded specimens of sandy soils containing different clay contents with different plasticity values. Based …

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Assessment Of Liquefaction-Induced Foundation Soil Deformations, K. Onder Cetin, Berna Unutmaz, H. Tolga Bilge May 2010

Assessment Of Liquefaction-Induced Foundation Soil Deformations, K. Onder Cetin, Berna Unutmaz, H. Tolga Bilge

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Although there exist some consensus regarding seismic soil liquefaction triggering assessment of free field soil sites, estimating the liquefaction triggering potential beneath building foundations still stays as a controversial and a difficult issue. Assessing liquefaction triggering potential under building foundations requires the estimation of cyclic and static stress state of the soil medium. In the recent studies (e.g. Unutmaz 2008), the cyclic stress ratio corrected for Kα and Kσ effects under and adjacent to building foundations subjected to cyclic loading are to be estimated with the help of a series of 2-D and 3-D numerical simulations for different …

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Comparison Of Three Procedures For Evaluating Earthquake-Induced Soil Liquefaction, John Liao, Jorge Meneses, Emre Ortakci, Zia Zafir May 2010

Comparison Of Three Procedures For Evaluating Earthquake-Induced Soil Liquefaction, John Liao, Jorge Meneses, Emre Ortakci, Zia Zafir

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Over the past decade, major advances have occurred in both the understanding and the practice with regard to the evaluation of soil liquefaction potential during earthquakes. Among these advances, there are two analytical frameworks (i.e., Seed et al. (2003) and Idriss and Boulanger (2008) procedures), which are widely accepted by the industry. The most significant achievement of the new procedures is their new criteria for assessment of liquefaction potential of low-plasticity silts and clays. These two new procedures are changing the way the design and regulatory communities consider soil liquefaction evaluation and may likely become standard-ofpractice in the near future. …

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