The Limitations Of Equivalent Linear Site Response Analysis Considering Soil Nonlinearity Properties,
2010
Amirkabir University of Technology (Tehran Polytechnic), Iran
The Limitations Of Equivalent Linear Site Response Analysis Considering Soil Nonlinearity Properties, S. M. Mir Mohammad Hosseini, M. Asadolahi Pajouh, F. Mir Mohammad Hosseini
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Seismic site effect has been a major issue in the field of earthquake engineering due to the large local amplification of the seismic motion. This paper presents the importance of an appropriate soil behavior model to simulate earthquake site response and gives a critical overview of the field of site response analysis. Some of the well known site response analysis methods are summarized and discussed. The objective of this paper is to investigate the influences of nonlinearity on the site response analysis by means of a more precise numerical model. In this respect, site responses of four different types of …
Weak Motion Linear Soil Amplification At Aegion, Greece, And Comparison With Seismic Design Codes,
2010
Aristotle University Thessaloniki, Greece
Weak Motion Linear Soil Amplification At Aegion, Greece, And Comparison With Seismic Design Codes, Olga-Joan Ktenidou, Dimitris Raptakis, Kyriazis Pitilakis
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
We use 473 weak motion surface records from a relatively soft soil site (CORSSA) and 81 from a relatively stiff soil site (DIM) in conjunction with downhole records obtained in rock in order to study linear seismic soil amplification in Aegion, Greece. We estimate peak ‘soil-to-outcrop’ amplification factors in the time domain for the two sites through linear regression of PGA values. We view the results derived from these very weak motion records as indicative of the entire linear elastic range based on the large dataset size. We compare the peak horizontal soil amplification factors we derive from records with …
Artificial Neural Network Model For Prediction Of Liquefaction Potential In Soil Deposits,
2010
Babol Noshirvani University of Technology, Iran
Artificial Neural Network Model For Prediction Of Liquefaction Potential In Soil Deposits, F. Farrokhzad, A. J. Choobbasti, A. Barari
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
With the increase in population, the evaluation of liquefaction is becoming more important for land use planning and development. In soil deposits under undrained condition, earthquakes induce cyclic shear stresses, may lead to soil liquefaction. Artificial neural network (ANN) is one of the, artificial intelligence (AI) approaches that can be classified as machine learning. Simplified methods have been practiced by researchers to assess nonlinear liquefaction potential of soil. In order to address the collective knowledge built up in conventional liquefaction engineering, an alternative general regression neural network model is proposed in this paper. To meet this objective, a total of …
Cpt-Based Comparative Mapping Of Liquefaction Hazard For Large Areas,
2010
University of Florence, Italy
Cpt-Based Comparative Mapping Of Liquefaction Hazard For Large Areas, Johann Facciorusso, Marco Uzielli, Giovanni Vannucchi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Liquefaction hazard mapping provides a useful tool for risk mitigation planning in seismic areas. Mapping for large areas is usually pursued by applying simplified criteria which rely on geological/lithological data and/or index properties of investigated soils, and in which local seismicity is not adequately considered (grade-1 methods). When a large number of in situ-tests and a reliable seismic hazard analysis are available, liquefaction hazard can be investigated by applying in-situ test-based methods accounting for seismic loading and the susceptibility of in-situ soil volumes (grade-2 methods). Advances in geotechnical earthquake engineering currently allow both deterministic and probabilistic evaluation of liquefaction potential …
Earthquake Induced Liquefaction Using Shake Table Test,
2010
College of Engineering, Pune, India
Earthquake Induced Liquefaction Using Shake Table Test, S. R. Pathak, R. S. Dalvi, A. D. Katdare
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Loose saturated cohesionless soils may undergo liquefaction due to strong ground motions. Such liquefaction causes significant damage to the structure resting on such soil. The extent of damage primarily depends upon soil properties, intensity of earthquake and type of structure. Various analytical models have been developed to estimate the likelihood of liquefaction of particular site based on field performance. However, if it is possible to identify the sites which are likely to liquefy due to specific intensity of earthquake it will help implementing the reduction in the damage which it would otherwise cause. One such analytical model has been developed …
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 …
Field Evidence And Laboratory Testing Of The Cyclic Vulnerability Of Fine-Grained Soils During The 1999 Kocaeli Earthquake,
2010
Missouri University of Science and Technology
Field Evidence And Laboratory Testing Of The Cyclic Vulnerability Of Fine-Grained Soils During The 1999 Kocaeli Earthquake, C. Guney Olgun, James R. Martin Ii, Atila Sezen
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Significant earthquake-induced settlements occurred in saturated fine-grained soils at the Carrefour Shopping Center in Turkey during the 1999 Kocaeli Earthquake (M=7.4). Most of the settlement was due to the undrained cyclic failure of silt/clay (ML/CL) and highplasticity clay (CH) strata within the subsoil profile. Each suffered about 1% vertical strain. Extensive laboratory testing on undisturbed samples from these silty and clayey strata has been performed to investigate this behavior. The laboratory testing included monotonic and cyclic simple shear tests, triaxial tests and conventional 1-D consolidation tests. Considerable pore pressure increases have been measured during cyclic simple shear test which was …
Seismotectonic Contours Of Kashmir-Hazara Region And Seismological Aspects Of October 08, 2005 Earthquake,
2010
WAPDA Directorate of Seismic Studies, Pakistan
Seismotectonic Contours Of Kashmir-Hazara Region And Seismological Aspects Of October 08, 2005 Earthquake, Syed Kazim Mahdi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
During the wee hours of October 08, 2005, a devastating shallow focused (16.2 km) earthquake with moment magnitude of Mw 7.7 occurred in the Pakistan’s Kashmir Hazara Region. Its tremors were felt in a radius of over 1000 km with damages taking place in an area of 36000 sq km. More than 0.1 million people died and the rehabilitation of infrastructures damages are estimated to cost around five billion dollars. The Kashmir Hazara terrain is located on the NW margin of lesser Himalaya. The KHS is one of the bold tectonic scars which physically isolate this terrain from rest of …
Static Load Induced Liquefaction, Steels Corners Road Embankment Failure,
2010
Gannett Fleming Engineers and Architects, P.C., Akron, OH
Static Load Induced Liquefaction, Steels Corners Road Embankment Failure, Mitchell W. Weber, Alexandre J. Bredikhin
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A simple, roadway widening became significantly more expensive when geologic conditions conspired to complicate the project. The widening was to be accomplished by the construction of a 25-foot wide and 15-foot high embankment. The embankment was located adjacent to a “wetland” area and pond. Fill placement begin and a height of 7 feet was reached when operations ceased for the week. Work began two days later. A 400-foot long scarp formed and the fill “moved” nearly 4 feet vertically and 1-foot laterally. An initial suspicion of settlement due to compression of peat was dismissed when no organic deposits were found …
2d Fem Analysis Of Earth And Rockfill Dams Under Seismic Condition,
2010
Indian Institute of Technology Kanpur, India
2d Fem Analysis Of Earth And Rockfill Dams Under Seismic Condition, Prabir K. Basudhar, N.S.V. Kameswara Rao, M. Bhookya, Arindam Dey
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The paper pertains to the seismic analysis of earth and rockfill dams with the aid of MSC_ Nastran (Windows) package. After validation, the package has been used to investigate the dynamic response of Tehri Dam, located in the seismically active region of Himalayas. A 2D FEM analysis is adopted wherein the dam has been modeled as a linear, elastic, non-homogeneous material. The base acceleration data of the Bhuj Earthquake has been used as an input motion. Effect of Poisson’s ratio and the ratio of the canyon length to the height of the dam has been investigated and is reported. Acceleration-time …
An Empirical Predictive Relationship For Assessing The Seismic Stability Of Slopes,
2010
Virginia Tech, Blacksburg, VA
An Empirical Predictive Relationship For Assessing The Seismic Stability Of Slopes, Jongwon Lee, Russell A. Green, Rachel Finch
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The objective of the study presented herein is to develop an empirical predictive relationship for permanent relative displacements for use in assessing the seismic stability of slopes, dams, and/or embankments subjected to active shallow crustal earthquake motions. A total of 330 horizontal motions, recorded at rock sites during 29 earthquakes in active shallow crustal regions (e.g., western North America: WNA), were used in this study. For each motion, the permanent relative displacements were computed using the Newmark sliding block procedure for a suite of yield-accelerations: 0.01, 0.05, 0.10, and 0.20 g. The predictive relationship proposed herein was derived by performing …
Effect Of Canyon Geometry And Ground Conditions On The Seismic Performance Of Tendaho Earthfill Dam In Ethiopia.,
2010
Institute of Geotechnical Engineering, BOKU, Austria
Effect Of Canyon Geometry And Ground Conditions On The Seismic Performance Of Tendaho Earthfill Dam In Ethiopia., Tensay G. Berhe, Wu Wei
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The seismic performance of earth dams is usually studied by two dimensional (2D) space. However, considerable judgment is required to estimate the overall three dimensional dynamic response of dams in a narrow canyon from plane strain analyses of individual sections of the dam. This is so because the plane strain analysis normally ignores the arching effect of the valley which is particularly relevant for dams in narrow valleys. Because of the arching action, the effect of the canyon geometry on the dynamic response of earth dams will be a stiffening of the system. The effect of the canyon geometry is …
Seismic Slope Stability Of Reactivated Landslides — A Performance Based Analysis,
2010
University of California Los Angeles, Fullerton, CA
Seismic Slope Stability Of Reactivated Landslides — A Performance Based Analysis, Binod Tiwari, Michael Hillman, Keyur Ajmera, Beena Ajmera
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The purpose of this study is to identify and analyze the differences between the various methods of slope stability analysis with respect to the height of the water table, and earthquake excitation. This was achieved through analysis of a cross section of the 2005 Bluebird Canyon Landslide in Laguna Beach, California. The profile was analyzed with the slope stability analysis software Rocscience Slide, using eight different methods, varying the water table in two meter increments and the seismic coefficient in increments of one tenth. A total of 15 different water tables were used with 10 different seismic loadings, yielding a …
The Effects Of Canyon Topography On Dynamic Stress Distribution In Earth Dams,
2010
Iran University of Science and Technology, Iran
The Effects Of Canyon Topography On Dynamic Stress Distribution In Earth Dams, Maryam Malekian, Amirata Taghavi, Mohammad Hassan Baziar, Shirin Salemi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Limitations of computer storage capacity and high costs have generally restricted the use of numerical methods to two-dimensional dynamic analyses of earth dams. However, differences in canyon topographies in which the earth dams have been built may cause various constraining effects. Comparison between results of plane strain and three-dimensional dynamic analyses may reflect the site effects especially in narrow canyons. Consequently, considering the geometry of canyon, one may choose an appropriate method of dynamic analysis. This paper presents the effect of different canyon geometries on amount and distribution of induced dynamic stresses in plane strain and in three-dimensional analyses. These …
Analytical Method For Seismic Bearing Capacity Of Stone-Column Reinforced Shallow Foundations,
2010
Islamic Azad University, Iran
Analytical Method For Seismic Bearing Capacity Of Stone-Column Reinforced Shallow Foundations, Javad Nazari Afshar, Mahmoud Ghazavi, Khashayar Hemmati
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Stone-columns is a useful method for increasing bearing capacity and reducing settlement of foundation soil subjected to structure loading. For stone-column construction, 15 to 35 percent of weak soil volume is usually replaced with stone-column material. Such columns may be constructed with various diameters, lengths, and center-to-center distances. This paper presents a simple method to determine the seismic bearing capacity of stone-column reinforced shallow foundation. For this purpose, a simple failure surface is assumed to characterize the failure stage of the stone column and soil materials using the concept of lateral active and passive earth pressures. The well known Mononobe-Okabe …
Computational Modeling Of A Large Pile Group Under Lateral Load,
2010
University of California, San Diego, La Jolla, CA
Computational Modeling Of A Large Pile Group Under Lateral Load, Jinchi Lu, Ahmed Elgamal, Charles Sikorsky, Thomas Shantz
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The lateral load resistance of pile foundations is critically important to the design of structures that may be subjected to earthquakes. This paper presents computational modeling results of the response of a large pile group system under lateral load. The open-source platform OpenSees is employed to conduct a nonlinear 3-dimensional finite element analysis. The piles are modeled by beam-column elements, and rigid beam-column elements are used to model the pile size (diameter). In order to facilitate the pre- and post-processing phases, a recently developed user interface OpenSeesPL is employed. Distribution of load within the pile group is presented and the …
Dynamic Response Of Pile Groups Embedded In Transversely Isotropic Media Using Hybrid Numerical Method,
2010
Sharif University of Technology, Iran
Dynamic Response Of Pile Groups Embedded In Transversely Isotropic Media Using Hybrid Numerical Method, B. Ghadimi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In this paper, the dynamic response of pile groups embedded in 3-D homogeneous transversely isotropic media subjected to time-harmonic vertical and horizontal loading is investigated. The response of pile groups is calculated by a novel method. This method is less complicated than boundary elements method (BEM) used in the most previous studies in this field. In the method the pile groups is discretized to some beam-column elements and radiation discs. The radiation discs represent the propagation of wave from piles to the unbounded soil medium. By calculating the dynamic stiffness of radiation discs and setting with beam-column elements, the dynamic …
Earthquake Input Motions And Seismic Site Response In A Centrifuge Test Examining Sfsi Effects,
2010
University of California at Berkeley, Berkeley, CA
Earthquake Input Motions And Seismic Site Response In A Centrifuge Test Examining Sfsi Effects, Henry B. Mason, Jonathan D. Bray, Katherine C. Jones, Zhiqiang Chen, Tara C. Hutchinson, Nicholas W. Trombetta, Benjamin Y. Choy, Bruce L. Kutter, Gregg L. Fiegel, Jack Montgomery, Roshani J. Patel, Robert D. Reitherman, Chandrakanth Bolisetti, Andrew S. Whittaker
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper describes the ground motion selection process and reports observed seismic site response and SFSI effects during a dynamic centrifuge test (Test-1). The centrifuge test is the first in a series of tests examining the effects of SFSI in dense urban environments. The objective of Test-1 is to examine SFSI effects for two structures that are located a significant distance apart and essentially isolated. The model structures represent a three-story building founded on spread footings and a nine-story structure founded on a threestory basement. The structures are sited on a dry, dense bed of Nevada Sand. The centrifuge model …
Effects Of Recorded Free-Field Motion On The Response Of Buildings Considering Soil-Structure Interaction Effects,
2010
Iran University of Science and Technology, Iran
Effects Of Recorded Free-Field Motion On The Response Of Buildings Considering Soil-Structure Interaction Effects, Fereidoun Amini, Masoud Shadlou
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
One of the intents of this study is to demonstrate some lacking accurate results of seismic code for considering soil-foundationstructure interaction (SFSI) effects. The other objective of this study is to evaluate the effects of type of recorded motion on the response of moderately flexible building considering SFSI effects. The effects of SFSI, under plane-strain conditions, have been studied by substructure approach for buildings supported by rigid foundations on a homogeneous, isotropic and elastic half-space. 32 data motions recorded in Imperial Valley-06 (1979) earthquake are used to demonstrate some intents of this study. It can be concluded that if it …
Experimental Soil - Foundation - Bridge Pier Interaction : Towards A Reversal Of Capacity Design,
2010
National Technical University of Athens, Greece
Experimental Soil - Foundation - Bridge Pier Interaction : Towards A Reversal Of Capacity Design, Ioannis Anastasopoulos, Takis Georgarakos, Vasilis Drosos, George Gazetas
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper presents a new seismic design philosophy, which under-designs the foundation to act as a “fuse” in case of strong seismic shaking. A simplified bridge pier is used to illustrate the advantages and disadvantages of this new philosophy compared to conventional capacity design. For this purpose, two alternatives are compared : one with an over-designed foundation, in accordance with conventional capacity design (so that the plastic “hinge” develops in the superstructure), and one with under-designed foundation. The performance of the two alternatives is investigated through shaking table testing of reduced scale models, using real accelerograms and artificial sinusoidal motions. …
