Evaluating Liquefaction Resistance Of A Calcareous Sand Using The Cone Penetration Test,
2010
University “Mediterranea” of Reggio Calabria, Italy
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 …
Evaluation Of Gravel Drains Effectiveness Against Liquefaction In Shaking Table Utilizing Energy Method,
2010
University of Urmia, Iran
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 …
Examination Of Existing Dmt-Based Liquefaction Evaluation Methods By Side-By-Side Dmt And Cpt Tests,
2010
National Cheng Kung University, Taiwan
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 …
Ground Motions And Liquefaction Potential,
2010
Bureau of Reclamation, Denver Federal Center, Lakewood, CO
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 …
Liquefaction Mitigation Using Air Injection,
2010
S&ME, Inc., Mount Pleasant, SC
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 …
Numerical Modeling Of Liquefaction In Layered And Silt Inter Layered Sands,
2010
Yıldız Technical University, Turkey
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 …
Optimum Depth Of Seismic Drains For Mitigating Large Deformations In Liquefied Ground With Hydraulic Barrier,
2010
Golder Associates Ltd., Canada
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 …
Parametric Investigation Of Lateral Spreading In Free-Face Ground Formations,
2010
National Technical University of Athens, Greece
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 …
Prediction Of Lateral Displacement Of Liquefaction Induced Ground Using Extreme Learning,
2010
National Institute of Technology Rourkela, India
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 …
Prediction Of Liquefaction Potential For Kolkata Region By Semi-Empirical Method,
2010
Jadavpur University, India
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 & …
Probabilistic Evaluation Of Field Liquefaction Potential Using Relative State Parameter Index (ΞR),
2010
Semnan University, Iran
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 …
Some Seismological Characteristics Of Mw 6.5 Pishin-Ziarat October 29, 2008 Double Earthquake,
2010
WAPDA Directorate of Seismic Studies, Pakistan
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 …
Spt-Based Evaluation Of Soil Liquefaction Risk,
2010
University of Catania, Italy
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 …
Verification Of Potential Flaws In Computing Liquefaction Po-Tential Index By 1999 Chi-Chi Earthquake In Taiwan,
2010
National Yunlin University of Science & Technology, Taiwan
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 …
A Probabilistic Method For The Prediction Of Earthquake-Induced Slope Displacements,
2010
University of Genoa, Italy
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 …
Accuracy Of Empirical Equations Predicting Sliding-Block Displacement,
2010
Hellenic Open University, Greece
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 …
Assessing Horizontal Seismic Coefficients In Earth Dams With Regards To Expected Deformation,
2010
Tarbiat Modares University, Iran
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 …
Assessment Of Soil-Nailed Excavations Seismic Failure Under Cyclic Loading And Pseudo-Static Forces,
2010
Tarbiat Modares University, Iran
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 …
Design Of An External Waste Rock Dump In An Opencast Coal Mine Standing Against A Hill In Seismic Prone Area Of India,
2010
Birla Institute of Technology, India
Design Of An External Waste Rock Dump In An Opencast Coal Mine Standing Against A Hill In Seismic Prone Area Of India, Indrajit Roy
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Landslides in external waste dump(i.e. waste rock material dumped outside the quarry) of Tikak opencast coal project, North Eastern Coalfield(NEC), (located in north eastern part of India) is a major hindrance to sustain coal production of 0.6-0.7 million ton per annum from NEC. The external dump is standing against a hill slope of 8 degree inclination and the quarry operation is going on the other side of the hill (Fig1). The present height of the external dump is 80metre which is planned to be increased to 180m. The project is situated in seismic zone – V of Indian seismic map …
Dynamic Slope Stability Analysis By A Reliability-Based Approach,
2010
National Council For Scientific Research, Lebanon
Dynamic Slope Stability Analysis By A Reliability-Based Approach, Dalia S. Youssef Abdel Massih, Abdul-Hamid Soubra, Jacques Harb, Mohamed Rouainia
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The analysis of earth slopes situated in seismic areas has been extensively investigated in literature using deterministic approaches where average values of the input parameters are used and a global safety factor or a permanent displacement at the toe of the slope is calculated. In these approaches, a decoupled analysis is usually performed in which a constant critical seismic acceleration is first calculated based on a pseudo-static representation of earthquake effects. Then, the permanent soil displacement is computed by integration of the real acceleration record above the critical acceleration. A reliability-based approach for the seismic slope analysis is introduced in …
