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Motion Amplification In Horizontal And Vertical Components At Liquefiable Sites, Jun Yang, Tadanobu Sato, Xiang-Song Li Mar 2001

Motion Amplification In Horizontal And Vertical Components At Liquefiable Sites, Jun Yang, Tadanobu Sato, Xiang-Song Li

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

This paper describes an analytical study with the purpose to gain some new understandings of the behavior of motion amplification in both horizontal and vertical components at liquefiable sites. By using a verified, effective-stress based nonlinear procedure, a series of numerical tests of a liquefiable sand deposit subjected to simultaneous action of horizontal and vertical shaking of various levels are carried out. To account for the characteristics of near-source motion, realistic array records of strong motion due to the Kobe earthquake of 1995 are employed to produce a variety of intensities of input motion in horizontal and vertical components. An …


Predicting The Maximum And Distribution Of Displacements On Liquefaction-Induced Lateral Spreads, Alan F. Rauch, James R. Martin Ii Mar 2001

Predicting The Maximum And Distribution Of Displacements On Liquefaction-Induced Lateral Spreads, Alan F. Rauch, James R. Martin Ii

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

Lateral spreading is the mostly horizontal movement of gently sloping ground due to liquefaction in shallow soil deposits. To assess the seismic hazards related to lateral spreading, estimates are needed of the maximum potential ground movement at these sites. One approach to this problem is to predict, using empirical models, the mean and standard deviation of the displacement magnitudes across the surface of a lateral spread. Then, using a probability density function, the maximum likely deformation at the site can be predicted with a suitable degree of conservatism. In the analysis described here, probability density functions are studied for modeling …


Cpt Evaluation Of Liquefaction Potential Using Neural Networks, Pradeep U. Kurup, Nitin K. Dudani Mar 2001

Cpt Evaluation Of Liquefaction Potential Using Neural Networks, Pradeep U. Kurup, Nitin K. Dudani

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

The increasing popularity of the cone penetration test (CPT) for site investigations has led to several methods for predicting liquefaction potential from CPT data. This paper describes a feed-forward neural network model trained by back-propagation for predicting liquefaction potential. The model requires the following seven input variables: cone resistance, total vertical stress, effective vertical stress, earthquake magnitude, maximum horizontal acceleration at ground surface, the mean grain size D50, and the seismic shear-stress ratio. A total of ninety-six data sets from different sites around the world were used for training, and eighty-two data sets were used for testing and …


Prediction Of Lateral Displacements Induced By Liquefaction In The Port Of Manzanillo, Mexico During The Earthquake Of October 9, 1995, Víctor M. Taboada-Urtuzuástegui, Francisco J. Villegas-Rodríguez, Francisco Hernández-Martinez Mar 2001

Prediction Of Lateral Displacements Induced By Liquefaction In The Port Of Manzanillo, Mexico During The Earthquake Of October 9, 1995, Víctor M. Taboada-Urtuzuástegui, Francisco J. Villegas-Rodríguez, Francisco Hernández-Martinez

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

This paper presents the prediction of the lateral displacements due to liquefaction in the yards of the Container Terminal at San Pedrito in the Mexican port of Manzanillo during the earthquake of October 9, 1995 (Ms=7.3, Mw=8.0). It describes briefly the results of field and laboratory tests carried out after the earthquake in order to obtain the required parameters to compute lateral displacements using the Newmark model and a modified Newmark block analysis which takes account of dilatant behavior; the models were calibrated with results of centrifuge experiments. Field data and simplified liquefaction analysis showed that …


Modeling Uncertainty In Seismic Stability And Earthquake Induced Displacement Of Earth Slopes Under Short Term Conditions, Azm S. Al-Homoud, Wisam W. Tahtamoni Mar 2001

Modeling Uncertainty In Seismic Stability And Earthquake Induced Displacement Of Earth Slopes Under Short Term Conditions, Azm S. Al-Homoud, Wisam W. Tahtamoni

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

Different models were developed for evaluating the probabilistic three-dimensional (3-D) stability analysis of earth slopes and embankments under earthquake loading using both the safety factor and the displacement criteria of slope failure. These models are formulated and incorporated within a computer program (PTDDSSA). The probabilistic models evaluate the probability of failure under seismic loading considering the different sources of uncertainties involved in the problem. A sensitivity analysis was conducted on the different parameters involved in the developed models by applying those models to a well-known landslides (Congress Street) under different levels of seismic hazard. The hypocentral distance and earthquake magnitude …


Earthquake-Induced Spalling Of Rock Slopes, Northridge Earthquake, January 17, 1994 — A Case Study, David Cummings Mar 2001

Earthquake-Induced Spalling Of Rock Slopes, Northridge Earthquake, January 17, 1994 — A Case Study, David Cummings

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

The 1994 Northridge earthquake (Mw=6.7, ML=6.4), southern California produced a 100-foot thick, 3,000-foot linear zone of fractures interpreted as a spalled slab near the crest of a ridge in the Simi Hills, 7 miles northwest of the epicenter. The strike and dip of the slab parallel the strike of the ridge and the dip of the topographic slope, respectively. The fractures cut across bedding and joint planes. An analytical model based on earthquake-induced stresses is used to describe the mechanism of spalling. Earthquake-induced tensile stresses are related to (I) propagation direction of the wavefront, (2) peak particle velocity, …


Is Newmark Method Conservative?, Mohsen Beikae Mar 2001

Is Newmark Method Conservative?, Mohsen Beikae

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

Newmark method is a commonly accepted practice in geotechnical earthquake engineering to estimate seismically induced displacement of earth structures. The method currently requires performing a series of analyses using multiple computer programs to 1) identify a potential sliding mass, 2) compute a factor of safety, 3) calculate a yield acceleration, and 4) perform a double integration of that portion of a given horizontal acceleration history that exceeds the yield acceleration. The Newmark method provides satisfactory results for a horizontal sliding surface. However, for an inclined sliding surface the result is unconservative and for a nonplanar one is not clear. To …


Large Motion Assessment In Soils Under Dynamic Loading, E. Foerster, H. Modaressi Mar 2001

Large Motion Assessment In Soils Under Dynamic Loading, E. Foerster, H. Modaressi

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

This paper presents the mathematical formulation of the nonlinear multiphase dynamic model meant for porous media, obtained by applying the finite transformation assumption. This assumption is appropriate when large motions take place either during mass wasting processes, such as large slumps and earthflows, or during earthquake events when site liquefaction occurs and results for instance in large irrecoverable settlements or lateral spreads. The weak formulation and numerical implementation of the dynamic model uses the mesh-free h-p clouds method, which is based on the more general Partition of Unity Method. The mesh-free numerical methods seem indeed to be more appropriate for …


3-D Dynamic Analysis For Stability Of Geotechnical Structures, Behrouz Gatmiri, Kamran-Charles Vossoughi, Bahar Jenab-Vossoughi Mar 2001

3-D Dynamic Analysis For Stability Of Geotechnical Structures, Behrouz Gatmiri, Kamran-Charles Vossoughi, Bahar Jenab-Vossoughi

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

This paper presents the interests of using a three-dimensional finite element model with an adequate elasto-plastic constitutive law for analyzing problems related to the construction of a complex geotechnical structure. As displacements and ground surface settlements are the key factors, which cause damages to the structure, these parameters have been carefully investigated. The stability of the whole structure is studied as well as the stability of each component. Both static and dynamic analyses (modal and spectral analysis) are performed.


Dynamic Design Of Ground Dams Under The Action Of Dynamic Loads, S. I. Umarkhonov Mar 2001

Dynamic Design Of Ground Dams Under The Action Of Dynamic Loads, S. I. Umarkhonov

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

Stress-strain state and non-stationary dynamic behavior of ground dam under kinematic action in the form of synthetic seismogram are studied in the paper by the method of finite differences. The regularity of deformation of dam material was taken as elasto-plastic one. Numerical results obtained are given in the form of graphs. The author of this paper worked out the methods using the finite-differential methods of M.Wilkins’ scheme and carried out the design of non-homogeneous ground dam with account of wave processes occurring in the body of the dam on seismic action. Numeric solutions of closed system of differential equations using …


A Simplified Method Of Vibration Analysis Of Layered Foundation And Applications In Pavement Parameter Identification, Fuming Wang, Yigong Ji, Maotian Luan Mar 2001

A Simplified Method Of Vibration Analysis Of Layered Foundation And Applications In Pavement Parameter Identification, Fuming Wang, Yigong Ji, Maotian Luan

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

In this paper, a simplified approach based on spline semi-analytical method is proposed for dynamic response analysis of visco-elastic layered half-space foundation. For varied geometrical and physical properties, the compliance function of layered non-homogeneous foundation is studied. Then an efficient and reliable numerical procedure for back-calculating material properties of pavement through the data measured from in-situ Falling Weight Deflectometer (FWD) tests is presented. The simulation results for in-situ data show that the proposed methodology is workable and applicable.


Past Proceedings: Fourth International Conference On Recent Advances In Geotechnical Earthquake Engineering And Soil Dynamics, San Diego (2001), Multiple Authors Mar 2001

Past Proceedings: Fourth International Conference On Recent Advances In Geotechnical Earthquake Engineering And Soil Dynamics, San Diego (2001), Multiple Authors

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

No abstract provided.


Prediction Of Volumetric Strain For Sand Under Cyclic Loading, Habib Shahnazari, Ikou Towhata Mar 2001

Prediction Of Volumetric Strain For Sand Under Cyclic Loading, Habib Shahnazari, Ikou Towhata

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

In order to investigate volume change of sand due to cyclic loading, different tests were performed on hollow cylindrical specimens under drained cyclic simple shear condition. Correlation of accumulated plastic shear energy with volumetric strain and effects of different parameters such as initial confining pressure, initial anisotropic consolidation and strain amplitude on this correlation were studied. Test results showed that volumetric strain of sand under different initial confining pressures was almost same. Volume change of specimens with different initial anisotropic consolidations was also identical, except for initial stage of shearing. It was found that the correlation of volumetric strain and …


Degradation Characteristics Of Clay-Shale Samples Under Cyclic Loading, M. Zoghi Mar 2001

Degradation Characteristics Of Clay-Shale Samples Under Cyclic Loading, M. Zoghi

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

It is known that reduction and degradation of soil strength and stiffness during cyclic loading typically result in damage to structural foundations and earth structures due to excessive settlement and tilting and may cause slope instability and embankment failure. Case histories, representing damages during earthquakes, due to this phenomenon are numerous. It is the guiding principle of this paper to present an overview of degradation characteristics of combined clay-shale samples under cyclic loading and describe how this phenomenon can be utilized in evaluating the seismic stability of slopes involving colluvium.


Post-Liquefaction Torsion Shear Tests On Sand With Various Strain Rates, Kiyoshi Kokeguchi, Atusushi Shimokawa, Jun Kohchi, Ikuo Towhata Mar 2001

Post-Liquefaction Torsion Shear Tests On Sand With Various Strain Rates, Kiyoshi Kokeguchi, Atusushi Shimokawa, Jun Kohchi, Ikuo Towhata

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

This text concerns with the deformation characteristics of liquefied sand which undergoes large residual deformation and flow failure. In particular, the nature of sand which can be used in a dynamic analysis of deformation in the time domain is aimed at. Although the former model tests have suggested a rate-dependent behavior of sand, a detailed measurement of stress and strain was not possible. This problem was overcome in the present study in which two types of torsional shear device were employed. A special care was therein taken to achieve such a large and realistic shear strain as 100% in a …


Measurement Of Shear Modulus Profile Using A Continuous Surface Wave Measurement System, S. Anand, E. C. Leong, H. K. Cheong Mar 2001

Measurement Of Shear Modulus Profile Using A Continuous Surface Wave Measurement System, S. Anand, E. C. Leong, H. K. Cheong

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

For most ground response analyses, the shear modulus is an important parameter to be determined and it has to be measured over a large strain range, so as to characterise the soil behavior under various loading conditions. Laboratory measurement of shear modulus covers a limited strain range depending on the test method. The main difficulty lies in the determination of the shear modulus at very small strains. In this respect, geophysical methods are more attractive. One of these test methods, which uses a continuous surface wave, is used to obtain the shear modulus profile at two sites in Singapore. The …


Dynamic Behavior Of Tailings, O. Flores C., M. P. Romo O. Mar 2001

Dynamic Behavior Of Tailings, O. Flores C., M. P. Romo O.

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

This article presents results of samples tested on a resonant column apparatus. The samples were formed of soil coming from mining residues (tailings), the testing program makes emphasis in the variables that influence the behavior. Finally, the interpretation of the results is made with a knowledge-based procedure and a Masing type model.


Identification Of Small Strain Dynamic Properties Of Dense Sand, Ahmed Elgamal, Tao Lai, Dan Wilson, Bruce Kutter Mar 2001

Identification Of Small Strain Dynamic Properties Of Dense Sand, Ahmed Elgamal, Tao Lai, Dan Wilson, Bruce Kutter

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

System identification techniques are employed to characterize the stiffness and damping characteristics of a dense sand stratum at low dynamic excitation conditions. The identification process utilizes a large database of input-output accelerations recorded in a highly instrumented centrifuge experimental program conducted by researchers at the University of California at Davis. This paper presents a computational effort based on the recorded small shaking events, where the peak ground surface acceleration ranges from 0.05g to 0.196g in amplitude. The dynamic behavior of the prototype stiff soil site near its first resonance is modeled by that of a one-dimensional shear beam. An employed …


Determination Of The Zone Of Destruction Of Soil And Rock Mass At Explosive Loads, B. E. Khusanov Mar 2001

Determination Of The Zone Of Destruction Of Soil And Rock Mass At Explosive Loads, B. E. Khusanov

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

This paper studies the behavior of grounds and rock mass under explosive loads using a new worked out model of deformation of ground and rock mass accounting structural destruction of grounds. Here mechanical characteristics of grounds are the functions on the degree of structural destruction (on the second invariant of the deviator of deformation). The problem on excitation propagation from hemispherical cavity cut from ground half-space, to the sides of this cavity a load is applied, imitating the action of explosion. The problem is solved numerically - by the method of finite differences according to the scheme offered by Wilkins …


Reflection And Refraction Of Quasi-P Wave Due To A Sandwich Isotropic Layer Between Two Monoclinic Half-Spaces, S. Saha, A. Chattopadhyay, D. Banerjee Mar 2001

Reflection And Refraction Of Quasi-P Wave Due To A Sandwich Isotropic Layer Between Two Monoclinic Half-Spaces, S. Saha, A. Chattopadhyay, D. Banerjee

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

The reflection and refraction of quasi-P(qP) wave below a transition isotropic layer sandwiched between two monoclinic media have studied. Due to incident of qP-wave at the interface of monoclinic lower half space and isotropic transition layer of thickness H, it will give rise to reflected qP, qSV, qSH-wave in the lower monoclinic half space and reflected P-wave and SV-wave at the isotropic transition layer of thickness H. As there is mother interface between transition layer and monoclinic upper-half space extended up to infinity, these two refracted P and SV-wave will incident at the interface with angle and 64 respectively. These …


Mathematical Modelling And Experimental Dynamic Investigation Of An Elevated Foundation Supporting Vibration Machinery, Ion Vlad Mar 2001

Mathematical Modelling And Experimental Dynamic Investigation Of An Elevated Foundation Supporting Vibration Machinery, Ion Vlad

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

In the last two decades rapid advances in the techniques for the design of engineering structures have been made. With this much progress it is surprising that mathematical modelling and experimental dynamic investigations of elevated foundations supporting vibration machinery has hardly progressed. The main factors contributing to this situation are the tendency for equipment manufacturers to rely on past successful practices, the lack of interest in academic circles for this type of engineering structures and the lack of funds for major studies. Romania, alongside of other countries prefered to consider the worldwide experience in this field instead of developing its …


Analysis And Behavior Of A Rigid Foundation Massif Under The Effect Of Vibrations (Application Of Barakan Method), Iddir Rabah, Laradi Nadir Mar 2001

Analysis And Behavior Of A Rigid Foundation Massif Under The Effect Of Vibrations (Application Of Barakan Method), Iddir Rabah, Laradi Nadir

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

This communication proposes a count mode of a rigid foundation massif frequencies, relaxing on a homogeneous soil, semi-infinite having an elastic linear behavior. Several data programs process using the finite elements method, are proposed for the dynamic analysis. Nevertheless, these programs don’t appear the physical phenomenon yielded, they depend on data introduced by the user and are applicable only for the elastic foundation massifs. The BARKAN method is an analytic one that appears the physical behavior of the different displacements and their coupling modes, the involvement of soil by its different dynamic stiffness modules, as well as a constant verification …


Seismic Displacements Of Rigid Retaining Walls, Yingwei Wu, Shamsher Prakash Mar 2001

Seismic Displacements Of Rigid Retaining Walls, Yingwei Wu, Shamsher Prakash

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

Rigid retaining walls experience significant displacements during earthquakes. Several investigations have developed 1-D and 2-D models to predict displacements. A critical review of the state of the art shows that these model may not predict realistic displacement Wu (1999). A new 2-D model, which considers strain dependent soil stiffness and material damping, sliding and rocking motions, and practical field water conditions behind the wall as per Eurocode (1994) have been presented. Typical results are included. A comparison of prediction and performance of a centrifuge model has shown good agreement. This model represents a considerable advance over the existing solutions and …


Seismic Active Earth Pressure Considering Effect Of Strain Localization, Jian-Min Zhang, Deji Li Mar 2001

Seismic Active Earth Pressure Considering Effect Of Strain Localization, Jian-Min Zhang, Deji Li

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

A new method, which is based on pseudo-static and limit-equilibrium analysis, was proposed for evaluating seismic (static plus dynamic) active earth pressures induced by backfill soils behind movable rigid retaining walls. It has the advantage over the Mononobe-Okabe method since it can take into account the effects of strain localization and post-peak reduction in the shear resistance that occur in the denser backfill soil during a strong earthquake.


Table Of Contents, Multiple Authors Mar 2001

Table Of Contents, Multiple Authors

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

No abstract provided.


Risk Analysis In Geotechnical And Earthquake Engineering, State-Of-The-Art Practice Of Embankment Dams, D. N. D. Hartford Mar 2001

Risk Analysis In Geotechnical And Earthquake Engineering, State-Of-The-Art Practice Of Embankment Dams, D. N. D. Hartford

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

Despite a proliferation of papers on quantitative risk analysis for dams during the past twenty years, risk analysis has not found widespread application in dam safety practice. Recent experience suggests that, despite a great deal of enthusiasm in the 1990’s, the professional opinion concerning the usefulness of risk analysis in dam safety practice is almost as divided now as it was in the early 1980’s. This paper presents an account of the history and development of risk analysis ln dam safety practice in the field of geotechnical earthquake engineering since its inception in the early 1960’s to September 2000. Against …


Vertical Earthquake Response Analysis Of Xiaolangdi Earth-Rock Dam With 3-D Shear Wedge Model, Zhenzhong Shen, Zhiying Xu Mar 2001

Vertical Earthquake Response Analysis Of Xiaolangdi Earth-Rock Dam With 3-D Shear Wedge Model, Zhenzhong Shen, Zhiying Xu

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

The constructing Xiaolangdi dam is the highest earth-rock dam in China. Its maximum height is about 154 m, and the length of dam axis is about 1500 m. In this paper, by application of the three-dimensional shear wedge theory and the Bubnov-Galerkin approach method, the vertical earthquake response analysis is performed for the earth dam. Its dynamic behaviors such as maximum dynamic displacement, velocity, acceleration and stress etc. are obtained. Under the action of the designed earthquakes, the fundamental period of the vertical vibration of the Xiaolangdi earth-rock dam is about 0.803 s, the maximum acceleration response is about 0.976 …


Refining Historical Earthquake Data Through Modeling And Scale Model Tests, Jong-Rim Lee, In-Kil Choi, Jeong-Moon Seo, Yo-Yoon Cho Mar 2001

Refining Historical Earthquake Data Through Modeling And Scale Model Tests, Jong-Rim Lee, In-Kil Choi, Jeong-Moon Seo, Yo-Yoon Cho

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

This study was performed for the reevaluation of historical earthquake records which occurred in Korea through tests and numerical analyses. For the scale model tests, static and cyclic lateral load tests on wooden frames that constitute a Korean ancient commoner’s house were conducted. Full-scale models of two types of frames were used for testing. Two 1:4 scale models were tested for rock and soil foundation conditions. Scaled real earthquake time histories were inputted for the tests. The peak ground acceleration (PGA) at the collapse of the house at the soil site was 0.25g, whereas PGA for moderate damage at the …


Dynamic Behavior Of Geogrid-Reinforced Soil, A. R. Santhakumar, Arvind K. Verma, T. V. S. R. Appa Rao Mar 2001

Dynamic Behavior Of Geogrid-Reinforced Soil, A. R. Santhakumar, Arvind K. Verma, T. V. S. R. Appa Rao

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

Geosynthetic materials particularly geogrids are widely used as reinforcement and is a proven technology for enhancing the performance of the foundation soil system under monotonic loadings. But the dynamic behavior of the reinforced foundation soil has not been well understood so far, and therefore dynamic loads (square wave pulse) of frequencies 0.2, 0.4 and 1 hertz under an amplitude of displacement of 2mm have been studied by carrying out dynamic plate loading tests on both unreinforced and the reinforced sandy beds. The size of the square plate is 150mm x 150mm x 30mm.


A System Dynamics Approach To Modeling Temperature Effects In Solid Waste, David A. Jokinen Mar 2001

A System Dynamics Approach To Modeling Temperature Effects In Solid Waste, David A. Jokinen

Theses and Dissertations

The amount of municipal solid waste discarded to landfills is continually increasing even with extensive recycling efforts. The need to understand the behavior of waste in landfills is increased due to the decreasing number of active landfills, communities' concern to the potential hazards associated with landfills, and companies or installations with landfills on-site need to understand landfill behavior comply with new legislation concerning design and detecting hazardous material movement of-site. This research is focused on increasing the understanding of landfill behavior by examining the effects of temperature in a landfill system. A system dynamics approach was used in this research …