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Articles 2431 - 2460 of 7869

Full-Text Articles in Civil and Environmental Engineering

Effect Of Elastic And Inelastic Dssi On Seismic Demands Of Sdofs Structures, Esteban Sáez, Fernando López-Caballero, Arézou Modaressi-Farahmand-Razavi May 2010

Effect Of Elastic And Inelastic Dssi On Seismic Demands Of Sdofs Structures, Esteban Sáez, Fernando López-Caballero, Arézou Modaressi-Farahmand-Razavi

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

In general, under earthquake loading, the soil reaches the limit of its elastic behavior before the structural elements. Thus, an earthquake analysis approach assuming inelastic structural behavior under fixed base condition or with elastic dynamic soil-structure interaction (DSSI) hypothesis may be inadapted. This paper describes the investigation conducted in order to define the contribution of the pure elastic DSSI effects in the complete inelastic DSSI problem. With this purpose, a comparative analysis between elastic and inelastic soil behavior assumptions for two inelastic single-degree-of-freedom (SDOF) structures and two soils is carried out. The results point out that, in general, inelastic soil …

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Effect Of Liquefaction On Pile Shaft Friction Capacity, M. E. Stringer, S. P. G. Madabhushi May 2010

Effect Of Liquefaction On Pile Shaft Friction Capacity, M. E. Stringer, S. P. G. Madabhushi

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

Piled foundations are commonly used worldwide, and observed failures of these foundations during earthquakes has led to active research in this area. However, the way in which piles support axial loads during earthquakes is still not fully understood. In this paper, the results from centrifuge tests are presented which consider how axial loads are carried by piles during earthquake loading. It will be shown that the piles in dry soils mobilise additional shaft friction to carry the seismically induced axial loading. However, in the case of a pile group passing through a liquefiable soil layer and founded in a dense …

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Evaluation Of Deformation Behavior Of Quay Walls Under Earthquake Loading, Masoomeh Khodabakhshi, Mohammad Hassan Baziar May 2010

Evaluation Of Deformation Behavior Of Quay Walls Under Earthquake Loading, Masoomeh Khodabakhshi, Mohammad Hassan Baziar

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

Ports are often regional economic centers and important components of regional and local transportation lifeline systems. Because of these reasons, the downtime of the ports due to natural disaster such as an earthquake results in severe economic loss. Gravity quay walls are the most common type of construction for docks because of their durability, ease of construction and capacity to reach deep seabed levels. Past earthquakes demonstrated that the seismic behavior of port structures such as quay walls was significantly governed by the properties of soils. The 1995 Hyogoken- Nanbu (Kobe) Earthquake brought great damage to structures in the Port …

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Experimental Study On The Performance Of Reinforced Sand Beds Under Repeated Loads In Presence Of Water, S. Vijaya, S. Gangadhara May 2010

Experimental Study On The Performance Of Reinforced Sand Beds Under Repeated Loads In Presence Of Water, S. Vijaya, S. Gangadhara

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

The performance and behavior of reinforced soil structure, both in the field and the laboratory are well documented. In the field situation, when the reinforced sand beds are used as a construction tool or as a ground improvement method, it is often the situation that they are subjected to the effect of water. In this study series of repeated load tests were conducted on mild steel square footing of 100mm size resting on a sand bed placed in a 500mm-dia, 390mm deep mild steel tank. Reinforcement location and spacing were selected based on optimization of previous research results. The sand …

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Fem Modelling Of A 3d Soil-Pile System Under Earthquakes, Francesco Grassi, Maria Rossella Massimino May 2010

Fem Modelling Of A 3d Soil-Pile System Under Earthquakes, Francesco Grassi, Maria Rossella Massimino

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

During earthquakes seismic wave crossing through soft soil can lead to significant curvatures on pile foundations, which in turn lead to significant bending moments. These bending moments are commonly named “kinematic bending moments”, to be distinguished from the “inertial bending moments” due to horizontal forces transferred from superstructures to pile heads. Approaches to carefully evaluate inertial bending moments have been recently developed world-wide; but the evaluation of the kinematic bending moments is still questionable. In this paper a 3D soil-pile FEM system is analysed. The system is subjected to seismic input motions, applied at the base of the system, which …

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Fixity Of Piles In Liquefiable Soils, Domenico Lombardi, Maria Giovanna Durante, Suresh R. Dash, Subhamoy Bhattacharya May 2010

Fixity Of Piles In Liquefiable Soils, Domenico Lombardi, Maria Giovanna Durante, Suresh R. Dash, Subhamoy Bhattacharya

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

Recent researches have shown that piles are laterally unsupported in liquefiable soils during most strong earthquakes. If this unsupported length is significantly large, the high axial load on piles may make them more vulnerable to buckling instability. Calculation of buckling instability requires the full unsupported length of pile, which is the sum of pile length above the ground, pile length in the liquefied soil and a depth of fixity below the liquefied soil layer. In this paper, the length of fixity of pile foundations embedded in liquefiable soils has been investigated using a simple numerical method. The finite element program …

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Influence Of Concentrated Mass On Pile Response Under Vertical Earthquake Excitation, Mahmoud Ghazavi, Amid Madhoushi May 2010

Influence Of Concentrated Mass On Pile Response Under Vertical Earthquake Excitation, Mahmoud Ghazavi, Amid Madhoushi

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

This paper presents an analytical solution to determine the kinematic and inertial response of a vertical pile embedded in a soil layer and subjected to vertical seismic excitation due to earthquake loading. The pile is assumed to have a circular cross section and perfectly connected to the soil. Also the soil stratum is assumed to be homogenous. The approach of Novak and his associates is used to derive the governing differential equation of the pile subjected to vertical harmonic vibrations. The kinematic response of the pile is first obtained considering stress free condition at the pile head and the ground …

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Influence Of Soil Nonlinearities On Dynamic Soil-Structure Interaction, Ali Gandomzadeh, Luca Lenti, Maria Paola Santisi D’Avila, Fabian Bonilla, Jean-François Semblat May 2010

Influence Of Soil Nonlinearities On Dynamic Soil-Structure Interaction, Ali Gandomzadeh, Luca Lenti, Maria Paola Santisi D’Avila, Fabian Bonilla, Jean-François Semblat

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

For moderate or strong seismic events, the maximum strains can easily reach the elastic limit of the soil behavior. Considering soilstructure interaction, the nonlinear effects may change the soil stiffness at the base of the structure and the energy dissipation into the soil. To take into account the nonlinearity of the soil in the dynamic soil-structure interaction (DSSI), a 3D constitutive model, proposed by Iwan, is used to investigate DSSI in the framework of the Finite Element Method. The model accounts for the nonlinear hysteretic behavior of soils and only needs the shear modulus degradation curve to characterize the soil …

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Lateral Response Of Bridge Pile Groups In Liquefiable Soil With Surface Non-Liquefiable Layer Using Shaking Table Test, Tang Liang, Ling Xianzhang, Xu Pengju, Gao Xia May 2010

Lateral Response Of Bridge Pile Groups In Liquefiable Soil With Surface Non-Liquefiable Layer Using Shaking Table Test, Tang Liang, Ling Xianzhang, Xu Pengju, Gao Xia

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

This paper conducts a shaking table test study on seismic response of low-cap pile groups and bridge structure in liquefiable ground. The soil profile in the test consisted of the horizontal saturated sand layer overlaid the silty clay layer. The base was excited by three different El Centro earthquake events. The preliminary liquefaction characteristics of ground firstly were analyzed. The bending moment of the pile was mainly introduce in the note. There’s no doubt that the shaking table test provided the necessary groundwork to study lateral response of bridge pile groups in liquefiable soil with surface non-liquefiable layer.

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Modeling The Influence Of Soil Structure Interaction On The Seismic Response Of A 5 Mw Wind Turbine, Ian Prowell, Ahmed Elgamal, Jinchi Lu May 2010

Modeling The Influence Of Soil Structure Interaction On The Seismic Response Of A 5 Mw Wind Turbine, Ian Prowell, Ahmed Elgamal, Jinchi Lu

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

In order to capture more energy, wind turbines are rapidly growing in height and rotor size. This growth increases the likelihood that soil structure interaction effects may influence the structural dynamic response. Current 3 MW turbines tower over the landscape with an 80 meter hub height and a 90 meter rotor diameter. This paper models a full soil structure system for the National Renewable Energy Laboratory onshore 5 MW reference wind turbine with a hub height of 90 meter and a 126 meter rotor diameter. A detailed finite element model of the turbine is created, including a full three dimensional …

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Non-Stationary Soil-Structure Interaction Analysis Of A Sdof System Subjected To Joint Horizontal And Vertical Seismic Excitations, Pranesh Chatterjee, Biswajit Basu May 2010

Non-Stationary Soil-Structure Interaction Analysis Of A Sdof System Subjected To Joint Horizontal And Vertical Seismic Excitations, Pranesh Chatterjee, Biswajit Basu

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

In this paper a formulation has been presented to obtain the non-stationary response of a single degree of freedom system resting on a single layered soil medium and subjected to simultaneous horizontal and vertical seismic excitations. The wavelet based analytical technique using the modified Littlewood-Paley function has been adopted to characterize the seismic ground motions. Subsequently, the system equations have been solved in wavelet domain and closed form solutions for the response of the structure have been derived. The response has been calculated using wavelet based formulation and the traditional complex valued transfer function. A numerical example is also presented …

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Numerical Modeling Of Soil-Pile Interaction In Liquefying Soils For A Water Crossing Bridge, Endi Zhai May 2010

Numerical Modeling Of Soil-Pile Interaction In Liquefying Soils For A Water Crossing Bridge, Endi Zhai

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

A recent design of a water crossing bridge encountered potential liquefiable soils beyond the depth that our standard-of-practice simplified liquefaction evaluation method (NCEER, 1997, Youd et al., 2001) can apply. A field investigation including deep soil borings and cone penetration test soundings was performed and revealed that loose to medium dense sandy alluvial soils are about 80 feet thick below the mud line. To evaluate liquefaction susceptibility of deeply buried soils and liquefaction effect on the response of the abutment Cast-In-Steel-Shell (CISS) piles, nonlinear effective-stress numerical models were built that were fullycoupled with a pore pressure generation scheme. The excess …

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Seismic Performance Assessment In Dense Urban Environments: Evaluation Of Nonlinear Building-Foundation Systems Using Centrifuge Tests, Zhiqiang Chen, Tara C. Hutchinson, Nicholas W. Trombetta, Henry B. Mason, Jonathan D. Bray, Katherine C. Jones, Chandrakanth Bolisetti, Andrew S. Whittaker, Benjamin Y. Choy, Bruce L. Kutter, Gregg L. Fiegel, Jack Montgomery, Roshani J. Patel, Robert D. Reitherman May 2010

Seismic Performance Assessment In Dense Urban Environments: Evaluation Of Nonlinear Building-Foundation Systems Using Centrifuge Tests, Zhiqiang Chen, Tara C. Hutchinson, Nicholas W. Trombetta, Henry B. Mason, Jonathan D. Bray, Katherine C. Jones, Chandrakanth Bolisetti, Andrew S. Whittaker, Benjamin Y. Choy, Bruce L. Kutter, Gregg L. Fiegel, Jack Montgomery, Roshani J. Patel, Robert D. Reitherman

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

In dense urban areas, buildings are generally constructed in clusters, forming city blocks. New buildings are designed assuming their response is independent of adjacent buildings, which ignores potentially important structure-soil-structure-interaction (SSSI) effects. Although a few studies have revealed the significance of SSSI effects, validated simulation and design tools do not exist. In this paper, we present the results from the first in a series of centrifuge tests intended to investigate SSSI effects. Results herein are focused on the design and measured response of two model building-foundation systems placed on dense dry Nevada sand and tested at 55-g. The two models …

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Seismic Performance Of Double Eps Geofoam Buffer Systems, Aurelian C. Trandafir, Steven F. Bartlett May 2010

Seismic Performance Of Double Eps Geofoam Buffer Systems, Aurelian C. Trandafir, Steven F. Bartlett

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

This paper presents the results of a dynamic finite-element analysis addressing the effectiveness of a double expanded polystyrene (EPS) geofoam buffer system in reducing the peak seismic loads on a rigid, non-yielding retaining wall during an earthquake. A double EPS geofoam buffer system involves two vertical EPS panels, i.e., one EPS panel placed against the rigid wall face and another EPS panel installed at a specific distance away from the first panel in the backfill soil. Sensitivity analyses of the seismic performance of the double EPS geofoam buffer system in relation to the spacing between the EPS panels indicate that …

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Seismic Performance Of Soil-Mix Panel Reinforced Ground, C. Guney Olgun, James R. Martin Ii May 2010

Seismic Performance Of Soil-Mix Panel Reinforced Ground, C. Guney Olgun, James R. Martin Ii

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

Ground reinforcement methods such as stone columns, jet grouting, and soil mixing are commonly used to improve subsoil conditions for seismic mitigation. In most cases, the purpose of this improvement is for foundation support and/or liquefaction mitigation. Additional benefits of the improvement, such as possible reduction in seismic ground motions, are not explicitly considered in NEHRP/IBC code provisions for establishing site classification and seismic design motions. Such reductions, if present, can have significant payoff. Reduced seismic loads on the super structure result in lower seismic design levels and reduced construction costs. It is conceivable that the cost of ground improvement, …

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Stiffness Coefficient In The Transition Zone Between Ballasted And Ballastless Track And Its Influence On Formation Stressing, Konstantinos Giannakos May 2010

Stiffness Coefficient In The Transition Zone Between Ballasted And Ballastless Track And Its Influence On Formation Stressing, Konstantinos Giannakos

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

In this paper, a parametric investigation of the static and dynamic elasticity (stiffness coefficient) of the railway track and of the elastic pads of the fastenings is presented for the cases of Ballastless Track (Slab Track and Embedded Track), Transition Zone and Ballasted Track. Moreover, the influence of the variation of the static and dynamic elasticity on the acting forces on the track superstructure and substructure is investigated, a factor that is of decisive importance for the design of the Track layers and conclusions are drawn for the magnitude of the acting forces and of the mean pressure on formation …

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The Effect Of Step Load Moving On The Surface Of A Cylindrical Cavity Using Neural Networks, Hamed Saeidi, Mansour Nikkhah-Bahrami May 2010

The Effect Of Step Load Moving On The Surface Of A Cylindrical Cavity Using Neural Networks, Hamed Saeidi, Mansour Nikkhah-Bahrami

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

Potential functions and Fourier series method in the cylindrical coordinate system are employed to solve the problem of moving loads on the surface of a cylindrical bore in an infinite elastic and isotropic medium. The steady state dynamic equations of medium are uncoupled by applying potential functions. The medium responses are obtained by using an appropriate numerical method of Laplace transform inversion. The solution has an integral form; therefore, a feedforward backpropagation neural network is designed and trained using the response evaluated numerically in a finite set of random points to approximate stress and displacement components in the medium. It …

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Numerical Modeling Of Buried Pipeline Crossing A Fault, Chaudhari Vasudeo Govind, Ramancharla Pradeep Kumar May 2010

Numerical Modeling Of Buried Pipeline Crossing A Fault, Chaudhari Vasudeo Govind, Ramancharla Pradeep Kumar

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

Pipelines are common transportation means for oil and natural gas, which act as an important lifeline facility for any nation. Often the design of these pipelines is a difficult task because they commonly are installed underground passing through different types of soil media. Many of these existing pipelines run through the faulted area, which continuously exposed to considerable risk of failure due to movement along the fault. In this paper, a numerical study is carried out to understand stress development in buried pipeline subjected to fault motion with Mundra-Delhi pipeline as a case study. For this purpose, a 3D finite …

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Response Spectrum Estimation Using Support Vector Machines, Jale Tezcan, Qiang Cheng, Lincoln Hill May 2010

Response Spectrum Estimation Using Support Vector Machines, Jale Tezcan, Qiang Cheng, Lincoln Hill

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

This study investigates the applicability and efficiency of support vector machines for the problem of estimating the earthquake response spectra from the Fourier amplitude spectra of the ground motion acceleration. Two methods are commonly used for this purpose: time domain simulations, and the random vibration theory. The use of time domain simulations offers high accuracy at high computational cost, while the use random vibration theory, although not computationally intensive, requires knowledge of the statistical distribution of the response amplitudes. This study treats the task of estimating response spectra from the Fourier spectra as a nonlinear regression problem, and constructs a …

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Analysis Of Aseismic Reliability Considering The Uncertainties Both Structural Parameters And Earthquake Loadings For The Gravity Type Earth-Retaining Wall, Zhiqiang Li, Jinbei Li, Yaping Kong May 2010

Analysis Of Aseismic Reliability Considering The Uncertainties Both Structural Parameters And Earthquake Loadings For The Gravity Type Earth-Retaining Wall, Zhiqiang Li, Jinbei Li, Yaping Kong

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

A simple numerical deterministic approach for evaluating stochastic properties of structural systems with uncertain parameters under random seismic excitations (“double-random problem”) is presented. The method is based on the impulse response function method, the perturbation law and random central differential law. On the other hand, the equivalent linear model is used to account for the nonlinearity of soil. On the basis of the above random response analysis method, the aseismic reliability of earth-retaining wall is calculated and the analysis flow of dynamic reliability under the stationary random seismic action is also presented. From the above analysis, we can see that …

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Dynamic Response Of Cantilever Retaining Walls Considering Soil Non-Linearity, Leuzzi Francesco, S. Foti, R. Lancellotta, G. Mylonakis May 2010

Dynamic Response Of Cantilever Retaining Walls Considering Soil Non-Linearity, Leuzzi Francesco, S. Foti, R. Lancellotta, G. Mylonakis

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

For many decades the analysis of earth retaining structures under dynamic or seismic conditions has been carried out by means of standard limit equilibrium (Coulomb, M-O) or elastic methods (Wood, Veletsos and Younan). These approaches are simplified, as they make use of considerable approximations which are often applicable only under particular conditions. A different and perhaps more realistic approach is possible using established computer codes, which integrate numerically the governing equations of the soil and wall media. Since these problems may involve significant levels of strain in the backfill, material non-linearity should be taken into account to realistically simulate the …

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Seismic Analysis And Fragility Curves Of Gravity Waterfront Structures, Kalliopi Kakderi, Kyriazis Pitilakis May 2010

Seismic Analysis And Fragility Curves Of Gravity Waterfront Structures, Kalliopi Kakderi, Kyriazis Pitilakis

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

The aim of the study is to propose adequate fragility curves for waterfront/ retaining structures for ground shaking without the presence of liquefaction, using available data from past earthquakes’ damages in Europe and worldwide and numerical analysis of typical cases. Existing fragility curves and damage states are evaluated and their shortcomings and/or limitations are assessed. Typical waterfront structures, with different geometry, foundation soil conditions and seismic excitations, are studied using appropriate numerical modeling. The corresponding damage levels are estimated with respect to the induced residual displacements and the seismic response of the soil-structure system. Considering aleatory uncertainties of the parameters …

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Seismic Analysis Of Retaining Wall Structures, Mohammadreza Abbasi Garavand, Alireza Saberi, Mona Salimi Ghezelbash May 2010

Seismic Analysis Of Retaining Wall Structures, Mohammadreza Abbasi Garavand, Alireza Saberi, Mona Salimi Ghezelbash

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

This paper describes 3-D finite element dynamic analysis of retaining wall structures with consideration of the soil-structure interaction. Purpose of this study is to reduce damages due to earthquake in such structures. For this reason, finite element program ANSYS has been used. The analysis data is based on 1995 Kobe earthquake report and the results have been verified with some retaining walls were damaged in that earthquake. To take into account the non-linearity of soil-structure surface, surface to surface contact element is used. One of the most important problems in dynamic analysis is modeling of infinite media. If hinge or …

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Seismic Lateral Earth Pressures On Retaining Structures, A. Murali Krishna May 2010

Seismic Lateral Earth Pressures On Retaining Structures, A. Murali Krishna

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

Various methods are available to estimate seismic earth pressures on soil retaining structures which cane be grouped to experimental, analytical and numerical methods. 1G model shaking table studies or high-g level centrifuge model shaking studies give some insight on the variation of seismic earth pressures along height of the retaining structure. In the simple analytical methods, M-O method based pseudo-static analysis is extensively used to evaluate seismic earth pressure variation and its probable resultant location. Pseudodynamic analysis method based analyses are also developed and are in progress for the same. Besides, these experimental and analytical methods, FEM or FDM based …

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Seismic Response Of Reinforced Soil Retaining Walls With Block Facings, Anitha Nelson, P. K. Jayasree May 2010

Seismic Response Of Reinforced Soil Retaining Walls With Block Facings, Anitha Nelson, P. K. Jayasree

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

Reinforced soil walls have become very popular in seismic areas owing to their flexible nature and cost effectiveness when compared to the conventional retaining structures. Although the use of reinforced soil walls with modular block facings and gabion facings is growing world wide at a rapid rate, the seismic response of these walls is yet to be analyzed. This paper discusses the response of these walls in terms of lateral facing deflection, reinforcement tensile force and crest surface settlement when subjected to seismic loading simulated by means of a variable amplitude harmonic vibration using the finite element analysis package, PLAXIS …

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Seismic Soil Pressures On Rigid Walls With Sloped Backfills, Guoxi Wu May 2010

Seismic Soil Pressures On Rigid Walls With Sloped Backfills, Guoxi Wu

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

Wood (1973) provided analytical solutions for the response of a rigid wall retaining elastic uniform soil backfill of finite length subjected to harmonic base excitation. Wu and Finn (1999) proposed a modified shear beam solution and derived closed-form formulations for computing dynamic soil pressures under harmonic loading. However, for rigid walls retaining sloped backfills, analytical solutions are not available for computing seismic soil pressures against the walls. In the current study, seismic soil pressures on rigid walls retaining 2H:1V (27°) sloped backfills have been computed using a total of eight acceleration time histories recorded in past large earthquakes. These records …

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An Upgrade Of The Microzonation Study Of The Centre Of Tirana City, Llambro Duni, Luljeta Bozo, Neki Kuka, Enkela Begu May 2010

An Upgrade Of The Microzonation Study Of The Centre Of Tirana City, Llambro Duni, Luljeta Bozo, Neki Kuka, Enkela Begu

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

An attempt was made in this paper to present an upgrade of the seismic microzonation of a part of the Tirana City. Some results of the previous, complete study performed in the late 80-s were used in this paper. The new aspect of this study is related to the probabilistic assessment of the ground motion parameters. Using gridded seismicity methodology, the PGA and the uniform response spectrum at the base rock corresponding to the 475-years return period were estimated. Based on them, five acceleration time histories are selected, which are later used to assess the response of the geotechnical models …

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Analysis Of Earthquake Site Response And Site Classification For Seismic Design Practices, Gloria M. Estrada May 2010

Analysis Of Earthquake Site Response And Site Classification For Seismic Design Practices, Gloria M. Estrada

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

In general, seismic provisions worldwide present different criteria for site classification, based on specific soil and rock properties, in order to determine representative design spectra for seismic design. On the other hand, results of site–specific analysis and seismic microzonation studies have shown not only the main properties of soil-rock profile that have marked influence on site response, but also site characteristics where it is necessary to carry out detailed and particular studies of earthquake ground response. This paper analyzes and compares site classification for seismic design of some seismic codes worldwide, with results of site-specific analysis and seismic microzonation studies. …

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Characterization Of The Elastic Displacement Demand: Case Study - Sofia City, Ivanka Paskaleva, Mihaela Kouteva, Franco Vaccari, Giuliano F. Panza May 2010

Characterization Of The Elastic Displacement Demand: Case Study - Sofia City, Ivanka Paskaleva, Mihaela Kouteva, Franco Vaccari, Giuliano F. Panza

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

The results of the study on the seismic site response of a part of the metropolitan Sofia are discussed. The neo-deterministic seismic hazard assessment procedure has been used to compute realistic synthetic waveforms considering four earthquake scenarios, with magnitudes M=3.7, M=6.3 and M = 7.0. Source and site specific ground motion time histories are computed along three selected cross sections, making use of the hybrid approach, combining the modal summation technique and the finite differences scheme. Displacement and acceleration response spectra are considered. These results are validated against the design elastic displacement response spectra and displacement demand, recommended in Eurocode …

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Comparison Of Liquefaction Potential Evaluation Based On Different Field Tests, Syed M. Ali Jawaid May 2010

Comparison Of Liquefaction Potential Evaluation Based On Different Field Tests, Syed M. Ali Jawaid

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

The lowlands of India are vulnerable to possible future large earthquakes. The liquefaction strength is estimated using in-situ tests and the factor of safety against liquefaction by comparing the liquefaction strength with cyclic shear stress ratio developed in the deposit during an earthquake. Standard Penetration test (SPT) and Cone Penetration test(CPT) have been most commonly used in-situ tests for characterization of liquefaction resistance. In this study, liquefaction potential is evaluated based on SPT as well as CPT data obtained from the three different locations situated in alluvial lowlands. A large difference in factor of safety against liquefaction is found based …

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