Centrifuge Model Tests Of Tieback Anchors And Drainage Pipes For Stabilization Of Slopes Under Earthquake Loads,
2010
Nippon Koei Co., LTD. Research and Development Center, Japan
Centrifuge Model Tests Of Tieback Anchors And Drainage Pipes For Stabilization Of Slopes Under Earthquake Loads, Keiichi Ota, Koji Takeya, Keiichi Itoh, Senro Kuraoka, Yuichi Ueno, Takaya Hiroshima
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Tieback anchors are widely used for the stabilization of natural and manmade slopes in Japan. The interactions between tieback anchors and slopes under seismic loading need to be understood to develop rational design concepts and installation methods in earthquake prone areas. We conducted centrifuge model tests to examine the characteristics of dynamic and residual loads on tieback anchors installed in slopes subjected to seismic loads. If the model slope contained a saturated zone, circular failure occurred even with pre-tensioned tieback anchors, and the amplitude of the oscillating loads on the tieback anchors was very high. This suggested that excess pore …
Cyclic Torsional Shear Tests To Obtain Dynamic Soil Properties For Seismic Design Of Road Embankments,
2010
Tokyo Denki University, Japan
Cyclic Torsional Shear Tests To Obtain Dynamic Soil Properties For Seismic Design Of Road Embankments, Susumu Yasuda, Takafumi Tsuruda
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Many road embankments have suffered damage during past earthquakes. The authors took soil samples from several embankments and conducted laboratory tests to demonstrate the mechanism of the damages and study appropriate seismic design methods. In the laboratory tests, cyclic torsional shear tests were carried out to obtain undrained cyclic strength, excess pore water pressure and shear modulus after cyclic loading of embankment soils. Test results showed a unique relationship between Plasticity Index and undrained cyclic strength is existed. Relationship between excess pore water pressure ratio and safety factor against liquefaction is also influenced by Plasticity Index. Then appropriate seismic design …
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 …
Earthquake Induced Slope Failure Simulation By Sph,
2010
Ritsumeikan University, Japan
Earthquake Induced Slope Failure Simulation By Sph, Ha H. Bui, R. Fukagawa, K. Sako, Y. Okamura
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Majority of slope stability, slope displacement and soil liquefaction analyses subjected to earthquake loading condition employed the finite element method (FEM) as the standard numerical tool. However, mechanism of soil failure in such condition often involved extremely large deformation and failure behaviors, which were unable to be modeled by FEM since this method was suffered from the grid distortion. In an attempt to overcome this limitation, we present herein our first attempt to extend the smoothed particle hydrodynamics (SPH) method to analyze slope failure behavior due to seismic shaking. For the sake of simplicity, effect of pore-water pressure was not …
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 …
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 …
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 …
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 …
Geotechnical Characteristics Of Seismically-Induced Aratozawa Landslide, Japan,
2010
The University of Tokyo, Japan
Geotechnical Characteristics Of Seismically-Induced Aratozawa Landslide, Japan, Ivan Gratchev, Ikuo Towhata
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper seeks to investigate the properties of volcanic soil from the Aratozawa landslide, the largest failure triggered by the 2008 Iwate-Miyagi Nairiku earthquake, Japan. Field investigation was carried out to estimate the in-situ characteristics of volcanic material. It was found that the soil was highly weathered, having low dry density and high moisture content. Laboratory examination included a series of triaxial compression tests which were performed to evaluate the dynamic properties of volcanic soil. Results of undrained cyclic loading tests indicated that the material had a high potential for generation of excess pore-water pressures, which could lead to a …
Effect Of A Slope On The Dynamic Properties Of Diluvial Terrace,
2010
Chiba University, Japan
Effect Of A Slope On The Dynamic Properties Of Diluvial Terrace, Shoichi Nakai, Yoko Nagata, Toru Sekiguchi
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
It is well known that landform influences the behavior of the ground during earthquakes. The objective of this study is to clarify the effect of a slope on the dynamic properties of diluvial terrace based on ground investigations, seismic motion observations and twodimensional finite element analyses, by choosing a target area that has a landform typical to the southern Kanto plain in Japan. Through the study, the followings were found: (1) Due to a weak soil along the slope, amplification becomes very large, but the area of influence is relatively small. (2) Amplification due to ground irregularity itself is relatively …
Finite Element Modeling Of The Las Colinas Landslide Under Earthquake Shaking,
2010
Norwegian Geotechnical Institute, Norway
Finite Element Modeling Of The Las Colinas Landslide Under Earthquake Shaking, Huynh Dat Vu Khoa, Hans Petter Jostad
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The Las Colinas landslide that occurred at Santa Tecla (El Salvador, Central America) due to the earthquake of 13 January 2001 is considered as one of the most destructive landslides ever known. This paper studies the ability of Hill’s sufficient condition of stability (1958), which is based on the sign of second-order work, for predicting and describing this catastrophic massive landslide. The general expressions of both local and global second-order work criteria and its implementation into finite element codes are given. By using the non-associated elasto-plastic Hardening Soil Model and the local second-order work criterion, it is demonstrated that potentially …
Improved Methodology For Estimating Seismic Coefficients For The Pseudo-Static Stability Analysis Of Earth Dams,
2010
University of Thessaly, Greece
Improved Methodology For Estimating Seismic Coefficients For The Pseudo-Static Stability Analysis Of Earth Dams, Achilleas G. Papadimitriou, Konstantinos I. Andrianopoulos, George D. Bouckovalas, Kostas Anastasopoulos
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper presents an improved methodology for estimating seismic coefficients for the pseudo-static stability analysis of earth dams, which is based on a statistical analysis of input data and results for 112 potential failure surfaces, as estimated from 28 two dimensional seismic response analyses for eight (8) different zoned earth dams and high embankments. The new methodology employs design diagrams and equations and estimates the maximum and the effective seismic coefficients as a function of: (a) the peak ground acceleration at the free-field surface of the foundation soil, (b) the predominant period of the seismic excitation, (c) the eigenperiod of …
Evaluation Of Seismic Response Of External Mine Overburden Dumps,
2010
Indian Institute of Technology, India
Evaluation Of Seismic Response Of External Mine Overburden Dumps, Radhakanta Koner, Debashish Chakravarty
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The stability of mines external overburden dump slope experiencing an earthquake is controlled by deformations; consequently a stability analysis that predicts slope displacements is desirable. The amount of displacement, deformation occur at the crest of the overburden dumps is an important factor for the seismic loading response of the dumps for the field personnel at the mine site for designing the dump slope geometry. The state of effective stress and seismic intensity significantly affects the stability range. In this paper, a simplified approach is presented for the seismic response of overburden dumps, and the role played by relevant parameters such …
Incorporation Of The Spatial Correlation Of Arias Intensity Within Earthquake Loss Estimation,
2010
Imperial College London, U.K.
Incorporation Of The Spatial Correlation Of Arias Intensity Within Earthquake Loss Estimation, Roxane Foulser-Piggott, Peter J. Stafford
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Arias Intensity (Ia) has been identified as an efficient intensity measure for the purpose of estimating the likelihood and extent of landslides. This efficiency implies that Arias intensity may logically be used within earthquake loss estimation applications in order to ultimately estimate the damage to spatially-distributed systems or portfolios. In order to estimate the effects of ground motions on such spatially-distributed systems it is important to take into account the spatial correlation of the intensity measure. However, existing landslide loss-estimation models, which use Ia as an input, do not take this aspect of the ground motion into account. …
Landslide Hazard Mapping And Assessment In Himalayas,
2010
Indian Institute of Technology Roorkee, India
Landslide Hazard Mapping And Assessment In Himalayas, A. K. Pachauri
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Himalayas offer a good opportunity to study landslides in hard terrains. The region is a well established seismic region of Asia where earthquakes are common occurrence. The on going plate motion and its collision with Asian plate is the main triggering factor for landslides, but there are geological factors that make the slopes susceptible for landslides to be triggered during rains. The Yatra routes of Char Dham the four pilgrimage centers where millions of Hindus go each year for salvation and heaven abode have to face road blocks each rainy season. The border road organization the pioneer organization looking after …
Nonlinear Time-Domain Analysis Of A Sliding Block On A Plane,
2010
Arizona State University, Tempe, AZ
Nonlinear Time-Domain Analysis Of A Sliding Block On A Plane, Mohamed G. Arab, Edward Kavazanjian Jr., Neven Matasovic
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A time domain finite difference numerical model of a sliding rigid block on a plane is developed using a simple elastic-perfectly plas-tic Mohr-Coulomb interface model. The model is shown to accurately predict the slip-stick and slip-slip behavior deduced from an analytical solution for behavior of a sliding block on a horizontal plane and the results of physical model tests of a block on both hori-zontal and inclined planes subject to harmonic and non-uniform excitation provided the appropriate interface strength is employed. Back analyses of the physical model tests show that for some geosynthetic interfaces, the interface shear strength depends upon …
Numerical Analysis Of Failure Of Rudramatha Dam Section During 26Th January, 2001, Bhuj Earthquake,
2010
Indian Institute of Science, India
Numerical Analysis Of Failure Of Rudramatha Dam Section During 26Th January, 2001, Bhuj Earthquake, Amit Srivastava, G. L. Sivakumar Babu
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
On 26th January, 2001, the Kachchh region of Gujarat, India faced devastating earthquake of magnitude 7.6 (Mw) popularly known as “Bhuj” earthquake. Various man made facilities including earthen dams faced varying level of damages during the earthquake and one of the major causes of failure is attributed to wide spread liquefaction of foundation soil. In the present study, a typical Rudramata dam sections located in the Kachchh region is considered for the failure analysis using fully coupled nonlinear dynamic numerical code FLAC 5.0 with pore pressure generation capabilities under dynamic loadings. The analysis is performed using the acceleration …
On The Use Of Empirical Correlations For Estimating The Residual Undrained Shear Strength Of Liquefied Soils In Dam Foundations,
2010
Bureau of Reclamation, Denver, CO
On The Use Of Empirical Correlations For Estimating The Residual Undrained Shear Strength Of Liquefied Soils In Dam Foundations, David Rees Gillette
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Current practice (2009) for seismic analysis of embankment dams relies heavily on empirical correlations with penetration resistance (standard penetration test or cone penetration test) to predict the residual undrained shear strength of liquefied foundation materials. At least six such relationships have been published for the SPT alone, in different “formats.” Some apply a fines adjustment to the SPT blowcounts, but others do not; some express the predicted strength as a ratio with pre-earthquake effective overburden stress, whereas others predict it directly, without explicit consideration of overburden. For the foundations of embankment dams, the difference between the strength-ratio approach and prediction …
Repair Of Landslide "Umka-Duboka" — Seismic Performance Assessment,
2010
IZIIS, Macedonia
Repair Of Landslide "Umka-Duboka" — Seismic Performance Assessment, Vlatko Sesov, Zeljko Zugic
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The Umka-Duboko is a large active landslide in the depth of 10-26 m, created in marly clays, taking up the area of 1.8 sq.km. According to the fact that the new road facility corridor located at the right bank of Sava river, on the meandering apex, crosses the landslide in the length of 3 km the characteristic remediation design solution is given. In this paper is observed seismic performance of this project. The analysis of potential liquefaction in motorway embankment and seismic stability of slope retained by embankment and hydraulic structure were made. The necessity was despite the limited seismic …
Seismic Analysis Of The Reservoir-Earth Dam-Pore Fluid System Using An Integrated Numerical Approach,
2010
Itasca Consulting Group, Inc., Minneapolis, MN
Seismic Analysis Of The Reservoir-Earth Dam-Pore Fluid System Using An Integrated Numerical Approach, Yanhui Han, Roger Hart
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In this paper, an integrated numerical approach is proposed for analyzing the seismic response of the reservoir-earth dam-pore fluid system subjected to earthquake loading. The fluid-mechanical coupling approach is deployed to capture the fluid-solid matrix coupling effects automatically. A hysteretic damping constitutive law is adopted to follow the modulus reduction and damping ratio curves. The Finn-Byrne equation is used to represent the shear-induced volumetric strain behavior of liquefiable materials. The interaction between the reservoir water and the dam boundary is treated as a dynamically updated pressure boundary condition. The deconvolution is accomplished by the equivalent linear program SHAKE. An automatic …
