Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2010

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 2011 - 2040 of 5375

Full-Text Articles in Engineering

Site Specific Seismic Analysis Of A Deep Stiff Soil Site, S. Krishna Kumar, A. Boominathan May 2010

Site Specific Seismic Analysis Of A Deep Stiff Soil Site, S. Krishna Kumar, A. Boominathan

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

Site specific analysis was carried out for a deep stiff soil site located near Ahmedabad, India. The site predominantly consists of sandy clay and silty sand layer in the top 30m with Vs varying from 430 to 750m/s. It is followed by a high plastic stiff clay layer cemented with sand and gravel with unusually high Vs above 1000m/s. The study region surrounded by 13 major faults has experienced several major earthquakes including the disastrous Bhuj earthquake (Mw=7.7). The seismic hazard level at the site was estimated by deterministic approach and the East Cambay fault with Mw of …

Go to article

Site-Specific Response Analysis In The New Madrid Seismic Zone, Wei Zheng, Youssef Hashash, Mark M. Petersen, Andrew S. Whittaker May 2010

Site-Specific Response Analysis In The New Madrid Seismic Zone, Wei Zheng, Youssef Hashash, Mark M. Petersen, Andrew S. Whittaker

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

A coal-fired power plant, Plum Point Energy Station, is being built in the city of Osceola, Arkansas, which is located in the New Madrid Seismic Zone (NMSZ). The project site is characterized as Site Class F, according to ASCE-7-05, because the soils at the site are prone to liquefaction. The depth of soil to rock is approximately 1 kilometer (km). A site-specific response study was required by the building code to determine the uniform hazard spectrum at the ground surface. The site-specific study included a probabilistic seismic hazard assessment to determine the Maximum Considered Earthquake (MCE) spectrum at an equivalent …

Go to article

Topographic Site Effects Evaluation For The Monte Po Hill In The City Of Catania (Italy), Antonio Ferraro, Salvatore Grasso, Michele Maugeri May 2010

Topographic Site Effects Evaluation For The Monte Po Hill In The City Of Catania (Italy), Antonio Ferraro, Salvatore Grasso, Michele Maugeri

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

The Monte Po Hill is located in the North-eastern part of the city of Catania; this area is prone to high seismic risk due to the presence of several constructions, including a school, in the vicinity of a toe of a slope, characterized by precarious stability conditions. The study has regarded the evaluation of site effects in correspondence of the site, to which corresponds a different value of the Seismic Geotechnical Hazard. In the beginning of 2007 a seismic station has been also located into the school building, with the aim of recording seismic events. Seismograms obtained by the seismic …

Go to article

A Note On The Effect Of Non-Plastic Fines On The Liquefaction And Reconsolidation Volumetric Strain Behaviour Of Sands, T. G. Sitharam, B. V. Ravishankar, J. S. Vinod May 2010

A Note On The Effect Of Non-Plastic Fines On The Liquefaction And Reconsolidation Volumetric Strain Behaviour Of Sands, T. G. Sitharam, B. V. Ravishankar, J. S. Vinod

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

This paper discusses the influence of non- plastic fines on the liquefaction and reconsolidation volumetric strain behaviour of sand based on the strain controlled cyclic triaxial experimental results. The investigations were carried out on sand samples collected from earthquake-affected area of Ahmedabad city of Gujarat state in India. Laboratory investigations were conducted on clean sand (prepared from the natural sand) samples with varying amount of non-plastic fines. Experimental results highlight a considerable influence of non-plastic fines on the resistance to liquefaction and reconsolidation volumetric strains behaviour during cyclic loading.

Go to article

Application Of General Regression Neural Networks (Grnns) In Assessing Liquefaction Susceptibility, Suzan S. Salem, Khalid El-Zahaby May 2010

Application Of General Regression Neural Networks (Grnns) In Assessing Liquefaction Susceptibility, Suzan S. Salem, Khalid El-Zahaby

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

Liquefaction is considered among the most important hazards associated with earthquakes. The damage resulting from seismic liquefaction may be huge; thus, there always exists needs to mitigate the damage associated with such risks. One of the main problems challenging geotechnical engineers is how to assess the seismic liquefaction hazard. Statistical and probabilistic approaches for seismic liquefaction are currently available. In this paper, a general regression neural networks approach (GRNNs) has been used to assess the liquefaction hazard in Egypt. Thus, data from new locations can be analyzed using GRNNs to obtain the liquefaction risk associated with this new site. The …

Go to article

Assessment Of Liquefaction Potential Relevant To Choice Of Type And Depth Of Foundations In Seismically Active Areas, Hadži-Niković D. Gordana, Perković D. Ilija, Abolmasov Biljana May 2010

Assessment Of Liquefaction Potential Relevant To Choice Of Type And Depth Of Foundations In Seismically Active Areas, Hadži-Niković D. Gordana, Perković D. Ilija, Abolmasov Biljana

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

There is evidence of great increase of pore pressures in saturated sand soils during cyclic loading caused by earthquakes. These increased pore pressures can often increase to effective stresses in soil. Dependant on sand density, this can lead to a total loss of shear strength, liquefaction or greater deformability of soil. Emergence of liquefaction or great deformations within soil can cause significant damage or total destruction of constructions on the ground, even when they have been correctly designed. For this reason, it is very important to perform detailed geotechnical and seismic investigations of ground conditions and evaluate liquefaction potential for …

Go to article

Assessment Of Liquefaction Susceptibility Of Geological Units In The Area Of Gulf Of Corinth, Greece, George Papathanassiou, Sotiris Valkaniotis, Spyros Pavlides May 2010

Assessment Of Liquefaction Susceptibility Of Geological Units In The Area Of Gulf Of Corinth, Greece, George Papathanassiou, Sotiris Valkaniotis, Spyros Pavlides

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

The coastal area of Gulf of Corinth is characterized as medium to high seismicity zone since devastating earthquakes occurred during a 2500 years period. One of the most characteristic events is the 373 B.C. Eliki earthquake that triggered severe secondary effects including soil liquefaction and large scale landslides. The basic aim of this paper is the compilation of a map regarding the liquefaction susceptibility in the coastal area of Gulf of Corinth, Central Greece. In order to achieve this, we used data regarding the age and depositional process of sediments the value of peak ground acceleration (PGA) and the occurrence …

Go to article

Case Histories Of Widespread Liquefaction And Lateral Spread Induced By The 2007 Pisco, Peru Earthquake, Jorge F. Meneses, J. Alva, B. Cox, V. Moreno, M. Olcese, R. Sancio, J. Wartman May 2010

Case Histories Of Widespread Liquefaction And Lateral Spread Induced By The 2007 Pisco, Peru Earthquake, Jorge F. Meneses, J. Alva, B. Cox, V. Moreno, M. Olcese, R. Sancio, J. Wartman

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

Case histories of widespread liquefaction and lateral spread induced by the Mw 8.0, 2007 Pisco, Peru earthquake and observed during a post-earthquake GEER reconnaissance are presented. A long duration of the earthquake over 200 seconds and two phases of strong ground motion induced widespread liquefaction and lateral spread of sand coastal deposits and road embankments over a total length of approximately 100 km of coastal region. Six case histories of liquefaction are presented and discussed including a massive lateral spread of a marine terrace believed to be as large or even larger than that reported along the Shinano River …

Go to article

Cyclic Instability Behaviour Of Sand-Silt Mixture Under Partial Cyclic Reversal Loading, Md. Abdul Lahil Baki, Sik-Cheung Robert Lo, Md. Mizanur Rahman May 2010

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 …

Go to article

Dem Simulation Of Liquefaction-Induced Lateral Spreading, Usama El Shamy, Mourad Zeghal, Ricardo Dobry, Tarek Abdoun, Sabanayagam Thevanayagam, Ahmed Elgamal May 2010

Dem Simulation Of Liquefaction-Induced Lateral Spreading, Usama El Shamy, Mourad Zeghal, Ricardo Dobry, Tarek Abdoun, Sabanayagam Thevanayagam, Ahmed Elgamal

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

This paper reports the results of a model-based simulation of 1g shake table tests of sloping saturated granular deposits subjected to seismic excitations. The simulation technique utilizes a transient fully-coupled continuum fluid discrete particle model of the watersaturated soil. The fluid (water) phase is idealized at a macroscale using an Eulerian averaged form of Navier-Stokes equations. The solid particles are modeled at the microscale as an assemblage of discrete spheres using the discrete element method. The interphase momentum transfer is accounted for using an established relationship. Numerical simulations were conducted to investigate the liquefaction induced lateral spreading of a mild-sloped …

Go to article

Effect Of Density On Critical Depth Of Liquefaction In A Soil Deposit Containing Double Loose Sand Lenses, S. M. Mir Mohammad Hosseini, Y. Pashang Pisheh, K. Shakiba Nia, N. Ganjian May 2010

Effect Of Density On Critical Depth Of Liquefaction In A Soil Deposit Containing Double Loose Sand Lenses, S. M. Mir Mohammad Hosseini, Y. Pashang Pisheh, K. Shakiba Nia, N. Ganjian

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

Large surface deformations due to liquefaction have been observed in many soil deposits which seem to feature good geotechnical characteristics. These deformations are often caused by the liquefaction of sand layers surrounded by clayey or silty soils called “sand lenses”. Liquefaction potential often decreases with increasing of depth. Hence, a specific depth of embedment of the lenses can be defined below which liquefaction would unlikely happen or the consequential surface deformation would be negligible. This depth is called critical depth. This research aims at studying the effects of the relative density of the sand within the lenses on the critical …

Go to article

Effective Stress Based Numerical Assessment Of Liquefaction-Induced Landslide At Degirmendere Cape, Izmit Bay During Kocaeli (Izmit)-Turkey Earthquake, Sevinc Unsal Oral, Kemal Önder Çetin May 2010

Effective Stress Based Numerical Assessment Of Liquefaction-Induced Landslide At Degirmendere Cape, Izmit Bay During Kocaeli (Izmit)-Turkey Earthquake, Sevinc Unsal Oral, Kemal Önder Çetin

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

This paper presents the numerical assessment of seismically-induced slope instability observed at Degirmendere Cape, Izmit Bay during Kocaeli (Izmit)-Turkey earthquake. As is evident from the name of the site, Degirmendere Cape site is located at the north of Degirmendere, on a small intrusion into the Bay of Izmit. At Degirmendere Cape, there existed a municipality owned hotel and recreational areas. During the earthquake following slumping of the fill material, the site was unindated. All the recreational facilities as well as the municipality hotel were lost to Marmara Sea with its residents. Failure mechanism was attributed to fault rupture/seismically induced slope …

Go to article

Evaluating Liquefaction Resistance Of A Calcareous Sand Using The Cone Penetration Test, Daniela Porcino, Vincenzo Marcianò May 2010

Evaluating Liquefaction Resistance Of A Calcareous Sand Using The Cone Penetration Test, Daniela Porcino, Vincenzo Marcianò

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

An experimental study based on Static Cone Penetration Tests (CPT) performed in Calibration Chamber (CC) and cyclic Simple Shear (SS) tests was undertaken in order to establish a correlation for estimating cyclic resistance ratio (CRR) of calcareous sands. CPT’s in CC were carried out on an uncemented calcareous sand, dug out from Brittany in France (Quiou sand) in the context of a previous research. Test results were thus re-analysed by the authors, considering the specific purposes of the paper. SS tests were conducted on specimens reconstituted by water sedimentation method that, according to the authors’ previous studies is capable of …

Go to article

Evaluation Of Gravel Drains Effectiveness Against Liquefaction In Shaking Table Utilizing Energy Method, Hadi Bahadori, Gholi Asadzadeh May 2010

Evaluation Of Gravel Drains Effectiveness Against Liquefaction In Shaking Table Utilizing Energy Method, Hadi Bahadori, Gholi Asadzadeh

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

Liquefaction is one of the major causes of damage to civil engineering structures. The shear strength of sandy soil during strong earthquakes is reduced due to exerted energy that is related to increasing of pore water pressure. The absorbed energy calculated through hysteretic stress-strain loops as compared with the exerted earthquake energy is an alternative method to study the liquefaction susceptibility of saturated sandy soil. There are several numbers of remediation methods which reduce the excess pore water pressure such as gravel drains. In the current study seven precisely performed 1-g shaking table tests are conducted. Synthetic Firouzkooh sand was …

Go to article

Examination Of Existing Dmt-Based Liquefaction Evaluation Methods By Side-By-Side Dmt And Cpt Tests, Gordon Tung-Chin Kung, Der-Her Lee, Pai-Hsiang Tsai May 2010

Examination Of Existing Dmt-Based Liquefaction Evaluation Methods By Side-By-Side Dmt And Cpt Tests, Gordon Tung-Chin Kung, Der-Her Lee, Pai-Hsiang Tsai

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

This study employed the field measurements of flat dilatometer test (DMT) and cone penetration test (CPT) presented by a recent study (Tsai et al. 2009) and additional DMT and CPT data conducted in this present study to examine the existing DMT-based liquefaction evaluation methods. Specifically, the DMT and CPT were conducted side-by-side at each of six in-situ sites and thus it is feasible to incorporate those test results into validating the existing DMT-based methods such as Grasso and Maugeri (2006), Monaco et al. (2005), and Rena and Chameau (1991). The DMT parameter, horizontal stress index (KD), is used …

Go to article

Ground Motions And Liquefaction Potential, Roger L. Torres May 2010

Ground Motions And Liquefaction Potential, Roger L. Torres

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

Strong earthquakes have the potential to produce liquefaction of saturated and loose soils or to produce shear strength loss on sensitive clays, which may produce embankment failure with uncontrolled release of the reservoir. Earthfill Dam 101 has been classified as a high risk dam and this study attempts to determine the extent of the risk. It retains a 60,000 acre-feet reservoir with population downstream of the embankment. The analysis of the earthquake through a bracketed accelerogram provides insight into how the embankment will respond to the seismic loading and to the soils properties. In the case study, the peak response …

Go to article

Liquefaction Mitigation Using Air Injection, William M. Camp Iii, Hugh C. Camp, Ronald D. Andrus May 2010

Liquefaction Mitigation Using Air Injection, William M. Camp Iii, Hugh C. Camp, Ronald D. Andrus

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

Soils most susceptible to liquefaction are loose, non-plastic and saturated. Because the compressibility of air is orders of magnitude greater than the compressibility of water, un-saturation or partial saturation can significantly increase the liquefaction resistance of a soil deposit. Nakazawa et al. (2004) have shown that cyclic strength in laboratory test specimens can be more than twice as high in partially saturated soil than fully saturated soil. It is hypothesized that sufficient de-saturation to increase the liquefaction resistance can be induced by injecting air or gas into the subsurface. Simple, qualitative shake-table experiments demonstrate the increase in liquefaction resistance as …

Go to article

Numerical Modeling Of Liquefaction In Layered And Silt Inter Layered Sands, Pelin Tohumcu Özener, I. Kutay Özaydın May 2010

Numerical Modeling Of Liquefaction In Layered And Silt Inter Layered Sands, Pelin Tohumcu Özener, I. Kutay Özaydın

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

In this paper, the pyhsical model tests which were carried out in the laboratory on uniform sand columns, silt inter layered sand columns and two layered sand columns deposited at various relative densities and subjected to different input accelerations are numerically modelled. The numerical analyses are performed by using Towhata-Iai liquefaction model in a finite element program called DIANA and the excess pore water pressures computed from the numerical analyses are compared with the experimental results. The numerical analyses have shown that the development of excess pore water pressures is highly influenced by the relative density of the sand and …

Go to article

Optimum Depth Of Seismic Drains For Mitigating Large Deformations In Liquefied Ground With Hydraulic Barrier, Mahmood Seid-Karbasi, Peter M. Byrne May 2010

Optimum Depth Of Seismic Drains For Mitigating Large Deformations In Liquefied Ground With Hydraulic Barrier, Mahmood Seid-Karbasi, Peter M. Byrne

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

Liquefaction of water saturated granular soils is one of the major risks that affect the safety and post-earthquake performance of infrastructure such as bridges, dams, buildings, and lifelines in various parts of the world. The seismically induced ground deformations are often the main concern when liquefaction occurs in significant zones of an earth structure or soil foundation. Recent studies including field data, centrifuge model testing and numerical investigations indicate that large lateral spreads and flow-slides in gentle sandy slopes have taken place when a low permeability silt/clay layer (hydraulic barrier) is present. One of the promising measures to alleviate this …

Go to article

Parametric Investigation Of Lateral Spreading In Free-Face Ground Formations, Alexandros Valsamis, George Bouckovalas, Vasiliki Dimitriadi May 2010

Parametric Investigation Of Lateral Spreading In Free-Face Ground Formations, Alexandros Valsamis, George Bouckovalas, Vasiliki Dimitriadi

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

Liquefaction-induced lateral spreading can cause extensive damage and even failure to foundations and earthworks resting inside or in the vicinity of the affected ground. The current practice for the evaluation of the ground surface displacement due to lateral spreading, is to rely upon a number of published empirical relations which are based on statistical analysis of field measurements. As an alternative, aimed to overcome a number of objective limitations related to the interpretation of field data, this article employs a numerical investigation to explore the main parameters affecting the anticipated maximum ground surface displacement and to quantify their effect in …

Go to article

Prediction Of Lateral Displacement Of Liquefaction Induced Ground Using Extreme Learning, Sarat Kumar Das May 2010

Prediction Of Lateral Displacement Of Liquefaction Induced Ground Using Extreme Learning, Sarat Kumar Das

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

Though various mechanistic based models are there for prediction of lateral displacement of ground, the statistical/ empirical methods based on the insitu data is most widely used. The artificial neural network method has been extensively used an alternate statistical method in different complex geotechnical engineering problems. Due to inherent difficulty of generalization in artificial neural network method, support vector machine, which is based on statistical learning algorithm is also being used. This paper describes use of extreme learning machine for prediction of large lateral displacement of liquefaction induced ground during an earthquake. Extreme learning machine is an artificial intelligence techniques …

Go to article

Prediction Of Liquefaction Potential For Kolkata Region By Semi-Empirical Method, P. Bhattacharya, S. P. Mukherjee, Biswajit Das May 2010

Prediction Of Liquefaction Potential For Kolkata Region By Semi-Empirical Method, P. Bhattacharya, S. P. Mukherjee, Biswajit Das

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

The present study was carried out to propose a relationship between shear wave velocity and N-value for the deltaic region of Kolkata. The relationship was derived from shear wave velocity determined from Cross-Hole test and SPT carried out at Rajarhat, Kolkata. The derived relationship was applied to evaluate the liquefaction susceptibility in terns of factor of safety against liquefaction for the subsoil deposits explored at Rajarhat, Kolkata area and the factor of safety obtained from the derived correlations was compared with those determined from Seed & Idriss (1971) and Andrus and Stokoe (2000). The shear wave velocity method (Andrus & …

Go to article

Probabilistic Evaluation Of Field Liquefaction Potential Using Relative State Parameter Index (ΞR), Yaser Jafarian, Mohammad H. Baziar, Alireza Sadeghi, Rouzbeh Vakili May 2010

Probabilistic Evaluation Of Field Liquefaction Potential Using Relative State Parameter Index (ΞR), Yaser Jafarian, Mohammad H. Baziar, Alireza Sadeghi, Rouzbeh Vakili

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

From the earliest studies of soil behavior under cyclic loading, it is found that the cyclic stress required for liquefaction onset is strongly affected by the relative density (Dr ) and initial effective overburden pressure of the soil. In this paper, relative state parameter index (ξR), which accounts for both relative density and effective stress, is used to evaluate the likelihood of liquefaction initiation in field condition. Two comprehensive databases of field case histories based on SPT and CPT are incorporated in the analyses. Logistic regression method is employed to derive a probabilistic expression that yields the …

Go to article

Some Seismological Characteristics Of Mw 6.5 Pishin-Ziarat October 29, 2008 Double Earthquake, Syed Kazim Mahdi May 2010

Some Seismological Characteristics Of Mw 6.5 Pishin-Ziarat October 29, 2008 Double Earthquake, Syed Kazim Mahdi

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

On October 29, 2008 two shallow focused earthquakes of Mw 6.5 struck the Pishin-Ziarat districts of Baluchistan in Pakistan. Both seismic events took place between 12 hours of each other with Intensity X and have been termed as Double Earthquake. The Earthquakes are located approximately 50 km northeast of the region of most intense damage from the Pakistan earthquake of May 30, 1935 (Mw 7.8), which is estimated to have killed 35,000 people. Field observations in the earthquake affected areas were undertaken field observations along previously mapped seismically active Gogai, Bibai and Kawas Tangi faults and study Seismological Characteristics such …

Go to article

Spt-Based Evaluation Of Soil Liquefaction Risk, Francesco Castelli, Valentina Lentini May 2010

Spt-Based Evaluation Of Soil Liquefaction Risk, Francesco Castelli, Valentina Lentini

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

The city of Catania in Sicily (Italy) been destroyed in the past by the 1169 earthquake with XI MCS intensity, the 1693 earthquake with X MCS intensity and the 1818 earthquake with VIII MCS intensity. The standard approach for the evaluation of the liquefaction susceptibility is based on the estimation of a safety factor between the cyclic shear resistance to liquefaction and the earthquake induced shear stress. The liquefaction potential index has been evaluated in the area of the Catania port, near Saint Giuseppe La Rena, that experienced liquefaction because of the 1693 and 1818 earthquake. The site under study …

Go to article

Verification Of Potential Flaws In Computing Liquefaction Po-Tential Index By 1999 Chi-Chi Earthquake In Taiwan, Chihping Kuo, Muhsiung Chang May 2010

Verification Of Potential Flaws In Computing Liquefaction Po-Tential Index By 1999 Chi-Chi Earthquake In Taiwan, Chihping Kuo, Muhsiung Chang

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

A widely used method for evaluating the damage and possibility of soil liquefaction, called Liquefaction Potential Index (PL), was proposed by Iwasaki in 1982. The values of 5 and 15 are the critical boundaries of PL to describe the damage which soil liquefaction will occur. The method is also adopted in the building design codes in Taiwan. The index is computed in form of integration by mul-tiplying the danger function (i.e. 1 minus safety factor) and the depth weight function. Theoretically, the computation should adequately reflect the liquefaction potential for the depth interval calculated. If the danger …

Go to article

A Probabilistic Method For The Prediction Of Earthquake-Induced Slope Displacements, Simone Barani, Paolo Bazzurro, Fabrizio Pelli May 2010

A Probabilistic Method For The Prediction Of Earthquake-Induced Slope Displacements, Simone Barani, Paolo Bazzurro, Fabrizio Pelli

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

This work presents a probabilistic method for estimating earthquake-induced nonlinear slope displacements. This method is applicable to any kind of slope, embankment and earth/rockfill dam. When coupled with Probabilistic Seismic Hazard Analysis at the slope site, it produces estimates of the annual probability that a permanent deformation of the slope will be exceeded. The proposed method uses a set of 2D numerical analyses with non-linear constitutive relationships for the soil formations to establish a probabilistic relationship between one or more ground motion parameters and the permanent displacement at a specific location within the slope. The analyses, which are performed using …

Go to article

Accuracy Of Empirical Equations Predicting Sliding-Block Displacement, Tryfon Thomaidis, Constantine A. Stamatopoulos May 2010

Accuracy Of Empirical Equations Predicting Sliding-Block Displacement, Tryfon Thomaidis, Constantine A. Stamatopoulos

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

The sliding-block model forms the basis of simple models predicting permanent co-seismic shear displacements of soils. For excitations consisting of actual accelerograms, different parameters of the applied motion have been used and different expressions have been proposed by researchers. Recently, many accelerograms have been recorded and these accelerograms are available in internet sites. These accelerograms allow the investigation of the accuracy of the expressions described above, some of which were based in a small number of accelerograms. In the present work the accuracy of empirical equations predicting sliding-block displacement is studied thru the application of 101 accelerograms covering a wide …

Go to article

Assessing Horizontal Seismic Coefficients In Earth Dams With Regards To Expected Deformation, Mohammad Hossein Tavakol, Ali Komak Panah May 2010

Assessing Horizontal Seismic Coefficients In Earth Dams With Regards To Expected Deformation, Mohammad Hossein Tavakol, Ali Komak Panah

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

One of the most important aspects that must be considered in design of embankment dams is to assess their stability during seismic events. When employing sophisticated approaches like finite element method for dynamic analysis of the mentioned structures against earthquake attacks, difficulties in evaluation of input parameters may exist. Hence employing simpler approaches like pseudo static method are still preferred by some designers. However, there is a problem associated with the pseudo static procedure as there is no organized technique for precise evaluation of horizontal seismic coefficient. Moreover, this method applies "safety factor" for the stability evaluations which is not …

Go to article

Assessment Of Soil-Nailed Excavations Seismic Failure Under Cyclic Loading And Pseudo-Static Forces, Ali Komak Panah, Sina Majidian May 2010

Assessment Of Soil-Nailed Excavations Seismic Failure Under Cyclic Loading And Pseudo-Static Forces, Ali Komak Panah, Sina Majidian

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

In this paper two numerical analysis methods (i.e. cyclic time history and pseudo-static) are applied to simulate the seismic behaviour and failure mechanism of soil-nailed structures. The numerical simulations are performed by using a finite difference software (Flac). Nevada sand soil parameters are used and construction sequences of nailed-structures are simulated prior to the cyclic and pseudo-static analyses. The results revealed that the failure pattern of two kinds of analyses are approximately similar and comprised of bilinear sliding surfaces. Furthermore, good agreement is found between failure pattern of two types of numerical analyses and previous experimental tests. based on comparison …

Go to article

First Prev Next Last