Natural Frequency Calculation Of A Pile-Soil System In Dry Sand Under An Earthquake Loading,
2010
Seoul National University, Korea
Natural Frequency Calculation Of A Pile-Soil System In Dry Sand Under An Earthquake Loading, Eui-Kyu Yang, Sun-Yong Kwon, Jung-In Choi, Myoung Mo Kim
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A new method was proposed in this study to evaluate the natural frequency of a pile-soil system under earthquake loading using a simple mass-spring model. The diagonal, 4x4, mass matrix in the model consisted of concentrated masses of a pile and a superstructure. The flexural stiffness of the pile and the spring stiffness between the pile and the soil were used to construct the stiffness matrix in the model. These two matrices were then input in the frequency equation for calculating the natural frequency of the pile system. The spring stiffness between the pile and the soil, which considerably influences …
Fixity Of Piles In Liquefiable Soils,
2010
University of Bristol, U.K.
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 …
Interaction Between Superstructure And Substructure In Railways,
2010
University of Thessaly, Greece
Interaction Between Superstructure And Substructure In Railways, Konstantinos Giannakos
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The railway track superstructure undertakes the forces that develop during train movement and distributes them towards its seating. The track panel (sleepers with their fastenings or slab with the fastenings) plays a key role in terms of load distribution, while at the same time it ensures the stability of the geometrical distance between the rails. Earthworks and ballast (if it exists) undergo residual deformations, settlements and lateral displacements, directly influencing the deterioration of the so-called geometry of the track, which can be nevertheless described much more specifically as quality of the track. In this paper, a parametric investigation of the …
Pile-In-Tube Foundations With Reserve Switch-Off Elements And Other Systems For Seismic Response Adaptive Control,
2010
Research Center for Earthquake Engineering and Urban Risk Mitigation (RCEE), Russia
Pile-In-Tube Foundations With Reserve Switch-Off Elements And Other Systems For Seismic Response Adaptive Control, J. M. Eisenberg
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Predominant ground motion frequencies and spectra could differ sufficiently at different earthquakes on one site. The reasons of the differences are the epicenter distance, the focal depth, and many others. As it is well known, the frequency spectral configuration and predominant frequency values influence the structural seismic response and seismic behavior of structures (Mexico earthquakes 1957, 1962; Bucharest, 1977, Spitak, Armenia, 1988 and other). The maximum seismic response depends of how close the fundamental frequency values of the structure are to the predominant ground motion frequencies. Seismoisolation as an effective approach to seismic response control became popular recent decades in …
Seismic Performance Assessment In Dense Urban Environments: Evaluation Of Nonlinear Building-Foundation Systems Using Centrifuge Tests,
2010
University of California at San Diego, La Jolla, CA
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 …
Numerical Modeling Of Soil-Pile Interaction In Liquefying Soils For A Water Crossing Bridge,
2010
HDR Engineering, Inc., Irvine, CA
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 …
Seismic Behavior Of Batter Pile Foundation: Kinematic Response,
2010
Shimizu Corp., Japan
Seismic Behavior Of Batter Pile Foundation: Kinematic Response, Takashi Tazoh, Masayoshi Sato, Jiho Jang, Yoichi Taji, George Gazetas
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
We carried out centrifuge tests to clarify the seismic behavior of batter-pile foundations. A vertical-pile foundation and a batter-pile foundation without the presence of a superstructure were installed parallel to each other in a soil container filled with dry sand, and were excited simultaneously. Through a comparison of the acceleration and displacement response of the footing, as well as the axial and bending strain of the piles for the two pile foundations, the kinematic response of the seismic behavior of the batter-pile foundation was experimentally investigated.
Numerical Analysis Of Disconnected Spread Footing On Soft Soil During Strong Earthquake,
2010
Bilfinger Berger Civil, Germany
Numerical Analysis Of Disconnected Spread Footing On Soft Soil During Strong Earthquake, Sascha Richter, Roberto O. Cudmani
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
For the design of the Golden Ears approach bridge in Vancouver (Canada) a disconnected spread footing (DSF) was considered as alternative to a conventional pile foundation. In a DSF, a spread footing rests on natural ground improved by piles. Footing and piles are separated by a layer of coarse grained material. The mechanisms governing the behavior of the DSF during strong earthquake events have been investigated in a numerical finite element (FE) analysis using a (visco-)hypoplastic constitutive relationship. The FE model consists of a soil column (height 45 m) which includes the concrete piles. The superstructure is represented by a …
Seismic Analysis Of Pile Group Using Pseudostatic Approach,
2010
Tehran University, Iran
Seismic Analysis Of Pile Group Using Pseudostatic Approach, H. Elahi, M. Moradi, H. G. Poulos, A. Ghalandarzadeh
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper evaluates a simple approximate pseudostatic method for estimating the maximum internal forces and horizontal displacements of pile group subjected to lateral seismic excitation. The method involves two main steps. At first the free-field soil movements caused by the earthquake are computed. Then the response of the pile group based on the maximum free-field soil movements which considered as static movements as well as a static loading at the pile head, which depends on the computed spectral acceleration of the structure being supported is analyzed. The methodology takes into account the effects of group interaction and soil yielding at …
Seismic Performance Of Double Eps Geofoam Buffer Systems,
2010
University of Utah, UT
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 …
Seismic Response Of Barrage Raft Floor Under Heterogeneous Soil Medium,
2010
Motilal Nehru National Institute of Technology, India
Seismic Response Of Barrage Raft Floor Under Heterogeneous Soil Medium, Kumar Venkatesh, A. D. Pandey, N. K. Samadhiya
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Seismic analyses of a barrage raft floor resting on homogeneous and heterogeneous subsoil condition were carried out by means of finite element modeling and analysis. Three dimensional models considering soil-raft-structure system were developed for both circumstances. The soil continuum, cut-off, pier, beam and abutment were modeled using eight noded brick element whereas raft floor was modeled using four noded plate bending element. The relevant amount of soil around and bottom of the barrage raft foundation has been modeled to find the effect of homogeneous and heterogeneous soil media on the seismic behavior of barrage raft floor. The seismic analysis was …
Seismic Soil-Pile Interaction: Physical Processes And Analytical Models,
2010
Parsons Brinckerhoff, Inc., New York, NY
Seismic Soil-Pile Interaction: Physical Processes And Analytical Models, Sanjeev Malhotra
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Seismic soil-pile-structure interaction (SSPSI) is a complex process involving several, simultaneously occurring and, sometimes compensating phenomena. The physical processes that occur in the soil when a pile supported structure undergoes earthquake loading consist of pore-pressure generation, ground deformation and subsequent cyclic degradation, strain rate effects and gap-slap mechanism. Modeling these physical phenomena numerically is a challenge. Of the various approaches available in practice, the p-y method for evaluating lateral pile response is by far the most common. However, at present, a consensus has not been established among practitioners on the appropriateness of using p-y curves for post-liquefaction analyses. This paper …
Soil-Structure Interaction Of Soft Clay Using Prefabricated Vertical Geodrains Under Seismic Stresses,
2010
The M.S University of Baroda, India
Soil-Structure Interaction Of Soft Clay Using Prefabricated Vertical Geodrains Under Seismic Stresses, Manish V. Shah, Arvind V. Shroff
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Experimental model study was carried out on soft Kaolinite clay using modified hydraulically pressurized oedometer with vertical sandwick of different diameter using open mandrel technique to investigate consolidation characteristics based on settlement and excess pore water pressure dissipation measurements. The main aim of this paper is to know the behavior of this consolidated mass under seismic stresses for different periods of time using shaking table.Pre and post shear strength of consolidated soil mass is evaluated using vane shear apparatus under seismic stresses. The interaction phenomena between clay and sandwick drain is also studied in oedometer to know stability of vertical …
Structure-To-Soil-Structure Interaction Analysis: A Case Study,
2010
Bechtel National, Inc., Frederick, MD
Structure-To-Soil-Structure Interaction Analysis: A Case Study, Lisa M. Anderson, Tarek Elkhoraibi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Current industry codes, such as ASCE 4-98 recommend consideration of Structure-to-Soil-Structure Interaction (SSSI) only when it is determined to have a significant effect on local results. In some cases, it is not computationally feasible, or too costly, to analyze an explicit model including a complex of all contributing structures. The significance of SSSI is dependent upon several variables, namely the characteristics of the soil, structures, and ground motion, as well as the spatial distance between structures. The SSSI effect is most significant for lighter structures adjacent to more massive structures that are founded on soil sites. The Hanford Waste Treatment …
The Effect Of Step Load Moving On The Surface Of A Cylindrical Cavity Using Neural Networks,
2010
University of Tehran, Iran
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 …
Times-History Finite Element Dynamic Analysis - Soil Nail Wall - San Manuel Casino - Highland, California,
2010
PB&A Inc., San Anselmo, CA
Times-History Finite Element Dynamic Analysis - Soil Nail Wall - San Manuel Casino - Highland, California, Pirooz Barar, Qing Liu
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The site of the proposed Phase II Parking Facility at the San Manuel Resort Casino, Highland, California, is on a sloped terrain where there is a 35 ft. grade differential from the north to the south end of the planned structure. PB&A, Inc. was selected to design a 12,000 square foot Soil-Nailed wall with a maximum height of 37 ft. to protect the Parking Structure from the soil pressures resulting from sloping ground conditions at the site. The project site is located within 100 feet of the San Andreas Fault in the highly seismic Southern California region, characterized by numerous …
Cyclic Instability Behaviour Of Sand-Silt Mixture Under Partial Cyclic Reversal Loading,
2010
University of New South Wales at Australian Defense Force Academy, Australia
Cyclic Instability Behaviour Of Sand-Silt Mixture Under Partial Cyclic Reversal Loading, Md. Abdul Lahil Baki, Sik-Cheung Robert Lo, Md. Mizanur Rahman
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Flow liquefaction is one of the most catastrophic failure phenomena in geotechnical engineering. It is a form of instability and can be observed during monotonic loading or cyclic loading. It is referred to as static instability/liquefaction for monotonic loading and cyclic instability for cyclic loading. To investigate the link between these behaviours, a number of stress controlled cyclic triaxial tests were carried out on loose sand-silt mixture under cyclic ‘reversal’ and ‘non-reversal’ loading condition. Cyclic reversal loading was partial reversal. Its peak-trough magnitudes were chosen in such a way that cyclic instability was triggered in compression side of the stress …
Comparison Of Three Procedures For Evaluating Earthquake-Induced Soil Liquefaction,
2010
Kleinfelder, Oakland, CA
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. …
Estimating Seismic Parameters Associated With Previous Earthquakes By Scptu Soundings In The Nmsz,
2010
Bechtel Power Corporation, Frederick, MD
Estimating Seismic Parameters Associated With Previous Earthquakes By Scptu Soundings In The Nmsz, Tianfei Liao, Paul W. Mayne
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Although the New Madrid seismic zone (NMSZ) is the most active seismic region in the eastern United States, paleoliquefaction features are often used to analyze the previous seismic activities, due to the long recurrence interval of large earthquakes. A new methodology is proposed in this paper to estimate the seismic parameters associated with previous earthquakes based on the results of seismic cone penetration tests (SCPT), using the simplified procedure of liquefaction analysis and the attenuation relationships developed for the corresponding seismic areas. This methodology is validated through the paleoliquefaction studies at two sites associated with the 1989 Loma Prieta earthquake …
Estimation Of Seismic Compression In Dry Soils Using The Cpt,
2010
Gregg Drilling & Testing Inc., Signal Hill, CA
Estimation Of Seismic Compression In Dry Soils Using The Cpt, P. K. Robertson, Lisheng Shao
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A popular method to evaluate earthquake induced settlements in dry sands is the approach proposed by Pradel (1998) which was based on standard penetration test (SPT) results and is only applicable to clean sands. A simple modification of the Pradel (1998) method is proposed based on cone penetration test (CPT) results and is extended to cover a wide range of unsaturated soils. A key parameter in the method by Pradel (1998) is the small strain shear modulus, Go, which can be estimated from the CPT or measured using the seismic CPT. The CPT can provide a continuous evaluation …
