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

Civil and Environmental Engineering Commons™

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

1995

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 121 - 150 of 442

Full-Text Articles in Civil and Environmental Engineering

Review Of Geotechnical Investigations Resulting From The Roermond April 13, 1992 Earthquake, P. M. Maurenbrecher, A. Den Outer, H. J. Luger Apr 1995

Review Of Geotechnical Investigations Resulting From The Roermond April 13, 1992 Earthquake, P. M. Maurenbrecher, A. Den Outer, H. J. Luger

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

In 1987 the Engineering Geology section of the Delft University of Technology carried out a survey of the SE Netherlands to determine which areas were susceptible to liquefaction based on soil profile, groundwater levels and a Richter scale magnitude 6 earthquake along the principal rift fault through the Netherlands, the Peelrand fault system. The fault system has been active since the Triassic and forms part of the Rhine-North Sea rift system. The last major earthquake along the Peelrand fault was in 1933. Recently, in 1992, A 5.8 magnitude earthquake occurred at Roermond, near to the Dutch-German border. Though damage resulting …

Go to article

Dynamic Modeling Of Layered Systems To Moving Surface Loads: Applications, Raj Siddharthan, Gary M. Norris, Mahmoud El-Gamal Apr 1995

Dynamic Modeling Of Layered Systems To Moving Surface Loads: Applications, Raj Siddharthan, Gary M. Norris, Mahmoud El-Gamal

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

Two important application of a recently developed moving load model are described. The model uses an efficient semi analytical "finite layer" formulation of the porous medium. One application is a response of a layered sandy nonlinear porous medium, while the other is a viscoelastic pavement layer system. The study reveals that the properties of the layers and porefluid and the moving velocity of the load are important factors that affect the response of the layered system.

Go to article

Scattering Of Sh-Waves By Arbitrary Surface Topography, M. E. Manoogian, V. W. Lee Apr 1995

Scattering Of Sh-Waves By Arbitrary Surface Topography, M. E. Manoogian, V. W. Lee

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

The weighted residual method was applied to the problem of scattering and diffraction of plane SH-waves by a shallow alluvial valley of arbitrary shape on the surface of a two-dimensional half-space. The formulation was also applied to the case of a shallow canyon. In order to demonstrate the versatility of the method, it was applied to shallow circular, shallow elliptical, and shallow rectangular canyons and alluvial valleys. Results obtained for the cases of a semi-cylindrical and a shallow semi-elliptical valleys and canyons match those obtained using closed form solutions. It was shown that significant ground motion amplifications, with respect to …

Go to article

Theoretical Investigations On The Nakamura's Technique, C. Lachet, P. Y. Bard Apr 1995

Theoretical Investigations On The Nakamura's Technique, C. Lachet, P. Y. Bard

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

We use synthetic calculations to investigate the spectral ratio between horizontal and vertical components (H/V ratio), derived from noise simulation, in order to appreciate the reliability of the so-called Nakamura's method for site effects applications. This ratio shows a peak whose position generally coincides with the fundamental resonance frequency. We show that this position is independent of the source function, whereas it is characteristic of the geological structure. We also compare these results with those obtained for vertical S waves and Rayleigh waves, in order to better understand the significance of this HIV peak. Finally, we show that the amplitude …

Go to article

Stress Wave Propagation In Unsaturated Sands, G. E. Veyera, C. A. Ross Apr 1995

Stress Wave Propagation In Unsaturated Sands, G. E. Veyera, C. A. Ross

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

Wave transmission tests were conducted on specimens of Eglin and Ottawa 20-30 sands at saturations varying from dry to near 100% using a Split-Hopkinson Pressure Bar. Specimens were compacted to a constant dry density in a thick-walled stainless steel container using a standard Proctor hammer. Compacted specimens were loaded in undrained, dynamic uniaxial confined compression at strain rates of approximately 13/s to 19/s. Tests were conducted on dry specimens; specimens compacted moist and tested moist; specimens compacted moist and dried before testing. For a constant input stress, transmitted stress and compressional wave propagation velocity were seen to vary with saturation. …

Go to article

Longitudinal Waves In A Rod In An Elastic Medium, A. Bodare, I. K. Eriksson, K. Samuelsson Apr 1995

Longitudinal Waves In A Rod In An Elastic Medium, A. Bodare, I. K. Eriksson, K. Samuelsson

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

The general equations for the propagation of longitudinal waves in an infinite cylindrical rod including the effect of a surrounding elastic medium have been derived in order to obtain the relationship between the circular frequency and the wave number. A comparison has then been made with the Smith model in order to investigate the limits of the model and to refine the expressions for the spring and damming constants.

Go to article

Dispersion Of Longitudinal Waves Propagating In A Continuum With Randomly Perturbated Parameters, J. Náprstek Apr 1995

Dispersion Of Longitudinal Waves Propagating In A Continuum With Randomly Perturbated Parameters, J. Náprstek

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

The author investigates the propagation of wave motion in a continuum the material parameters of which are random functions of longitudinal coordinate. The analysis is based on the theory of Markov processes and the subsequent solution on the respective Fokker-Planck-Kolmogorov equation. The fully deterministic response in the excitation point transforms into nonhomogeneous random process in the longitudinal coordinate with the growing distance. The quota of the deterministic component in overall response drops until it disappears completely. The model of uncorrelated imperfections (white noise) of the continuum is inacceptable, because it is at variance with the energy equilibrium law. The results …

Go to article

Response Of Alluvial Valleys To Incident Sh, Sv And P Waves, S. Ahmad, K. L. Fishman, H. Xue Apr 1995

Response Of Alluvial Valleys To Incident Sh, Sv And P Waves, S. Ahmad, K. L. Fishman, H. Xue

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

Results of an extensive numerical study on two dimensional wave scattering by valleys of semi-elliptical cross section due to incident SH, SV and P waves are presented. The investigation has been conducted using a rigorous Boundary element algorithm. The influence of key parameters, such as, valley depth, impedance ratio, frequency, and angle of incidence on surface ground motion are studied in detail. Furthermore, the case of a valley within a layered half space is analyzed and results compared with those obtained for a valley within a homogeneous half space.

Go to article

Effect Of Magnitude And Type Of Damping On Soil Amplification, Jose M. Roesset, Carlos I. Huerta, Kenneth H. Stokoe Ii Apr 1995

Effect Of Magnitude And Type Of Damping On Soil Amplification, Jose M. Roesset, Carlos I. Huerta, Kenneth H. Stokoe Ii

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

Soil Amplification studies conducted to obtain site specific seismic motions at the free surface of a soil deposit or at any other elevation (convolution process), or to determine compatible base motions at a given depth for soil structure interaction analyses (deconvolution) assume, when performed in the frequency domain simulating nonlinear soil behavior through an iterative linear analysis, that the internal soil damping is of a linear hysteretic nature. This tends to filter out excessively the high frequency components of motion for convolution studies and leads to eventual instability of the solution at a given depth (function of the soil properties) …

Go to article

Discussions And Replies — Session X, Multiple Authors Apr 1995

Discussions And Replies — Session X, Multiple Authors

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

No abstract provided.

Go to article

Simple Model For Active Isolation Of Machine Foundations By Open Trenches, S. Ahmad, T. M. Ai-Hussaini Apr 1995

Simple Model For Active Isolation Of Machine Foundations By Open Trenches, S. Ahmad, T. M. Ai-Hussaini

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

Ground disturbance due to waves generated by a machine foundation can be detrimental to adjacent structures or operation of sensitive equipment nearby. For machine foundations vibrating at moderate to high frequencies, the amplitude of ground motion can be reduced significantly by installing a wave barrier around the source. A three-dimensional boundary element algorithm incorporating quadratic elements has been used to perform an extensive parametric study on the effectiveness of open trenches as wave barriers. Based on the results of the study, a simple model in the form of an algebraic expression is developed for estimating the vibration screening effectiveness of …

Go to article

Assessment Of Ground Vibration From Passing Train, Ján Benčat Apr 1995

Assessment Of Ground Vibration From Passing Train, Ján Benčat

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

Increasing demands on speed increase, higher axle on transportation over dimensional and heavy loads cause simultaneous increase of unfavorable traffic effect on the structures of railways and on the train-induced ground vibration, respectively. This paper examines the residual problems of ground-borne vibration, the vehicle and track features which might be responsible for generation, how it is propagated, and how it might affect. A few of experimental results which have been obtained during studies made on Slovak Railways (ZSR) are presented in the paper, too.

Go to article

Dynamic Behavior Of Beijing Sandy Clay And The Dynamic Responses Of Beijing Subway To Traffic Vibrations, C. S. Pan, W. Cui, D. Li, F. Gao Apr 1995

Dynamic Behavior Of Beijing Sandy Clay And The Dynamic Responses Of Beijing Subway To Traffic Vibrations, C. S. Pan, W. Cui, D. Li, F. Gao

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

Experiments were carried out for the Beijing sandy clay using a triaxial apparatus Model DTC- 240 (JAPAN) with the dynamic characteristics of the soil obtained and formulated. The test data were applied to the 2-D and 3-D finite element analyses for the dynamic responses of Beijing Subway to traffic vibrations. Resulte acquired from the numerical analyses happened to be in good coincidence with the measured responses.

Go to article

Development Of New Stiffness And Damping Expressions For Footing Vibrations, H. V. P. Truong, P. J. Moore Apr 1995

Development Of New Stiffness And Damping Expressions For Footing Vibrations, H. V. P. Truong, P. J. Moore

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

New expressions for stiffness and radiation damping, which have been developed for a new forcing function, are based on the simple equation of wave propagation in a perfectly elastic half space for different modes of vibrations, particularly vertical and horizontal vibrations. A differential equation including the effect of foundation mass is presented and the results of the amplitudes of vibration obtained from this differential equation are compared with those in the standard differential equation in soil dynamics textbooks. Furthermore, added soil masses for vertical and horizontal vibrations are also derived based on the equation of wave propagation and discussed with …

Go to article

Response Of Embedded Circular Flexible Foundations, N. Gucunski Apr 1995

Response Of Embedded Circular Flexible Foundations, N. Gucunski

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

The stiffness matrix approach to the solution of vertical vibrations of a circular flexible foundation embedded in a viscoelastic layered half-space have been described. Results of a parametric study, represented by displacement and soil reaction distributions and impedances, indicate a significantly different responses of flexible and rigid foundations. Important parameters are identified and include: the stiffness ratio, depth of embedment, soil stratification and loading distribution. Influence of each of the parameters is discussed.

Go to article

Vibrations Of Impact Machine Foundations And Footing Settlements, M. R. Svinkin Apr 1995

Vibrations Of Impact Machine Foundations And Footing Settlements, M. R. Svinkin

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

Foundations under machinery that produce impact loads, such as in forge shops, are major industrial sources of wave propagation in soil. The resulting vertical soil vibrations may cause dynamic settlements of column footings. Analyzing of a number of case histories shows that dynamic settlements of footings under columns and connected with them exterior walls at forge shops occur relatively slowly when the soil conditions are different from saturated sands. There are other causes of extensive damage of shop exterior walls. For predicting the dynamic settlements from new machine foundations, it is necessary to know expected footing vibrations. These vibrations can …

Go to article

Interaction Of Adjacent Vibratory Machines, J. P. Lee, J. A. Bohinsky Apr 1995

Interaction Of Adjacent Vibratory Machines, J. P. Lee, J. A. Bohinsky

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

Due to inevitable unbalanced masses that always exist, a rotating machine will experience vibration to various extent depending on the characteristics of loads and support conditions. When two pieces of vibratory machines are installed close to each other, the vibration of either machine may further be amplified by the interaction between the two machines. In this paper, the interaction effect between two adjacent vibratory machines supported on a flexible floor was investigated. It was found that for the case investigated, the most critical condition occurred when the unbalanced forces were out-of-phase.

Go to article

The Reliability Aspects In Dynamic Engineering, G. Singh, B. M. Das Apr 1995

The Reliability Aspects In Dynamic Engineering, G. Singh, B. M. Das

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

Strides in dynamic engineering need to be accompanied by developments in risk appraisal of designs so as to respond to rapidly increasing sensitivity to and awareness of hazards. A practical, reliable and engineer-friendly methodology for design is presented in light of the critical review of the various current practices. An example is presented to illustrate the advantages of the preferred approach to improving, unifying and rationalizing design.

Go to article

Steady Vibration Of Flexible Circular Plate On An Elastic Half Space, X. Zeng, X. Qin, P. Gong, M. Iguchi Apr 1995

Steady Vibration Of Flexible Circular Plate On An Elastic Half Space, X. Zeng, X. Qin, P. Gong, M. Iguchi

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

The steady vibration of a flexible circular plate with finite rigidity resting on an elastic half space and subjected to harmonic vertical loads on the surface of the plate is studied in the present paper. The contact between the plate and the half space is assumed to be frictionless. Three types of load are considered: 1. the load uniformly distributed over the entire surface of the plate, 2. the load uniformly distributed over a ring zone of the surface of the plate, 3. the concentrated load applied at the center of the plate. By expanding the distribution of the contact …

Go to article

Non-Linear Response Of Foundation Systems Subjected To Vertical Machine Type Loading, Hatem Eibastawisy, Shamsher Prakash Apr 1995

Non-Linear Response Of Foundation Systems Subjected To Vertical Machine Type Loading, Hatem Eibastawisy, Shamsher Prakash

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

Vertical vibration tests on surface and embedded footings of different dimensions were performed by Fry (1963) and Beredugo (1971). Analytical predictions were reported by Manyando (1991) based on nonlinear, frequency independent stiffness and damping coefficients for surface foundations. The authors present, in this paper, a mathematical model for predicting the response, in terms of amplitude versus frequency, for surface or embedded, irregular shaped foundations system under vertical vibration considering soil non-linearity and frequency dependent stiffness and geometrical damping parameters. The frequency dependent stiffness and geometrical damping parameters are based on Gazetas's work (1991). The predicted and measured natural frequency and …

Go to article

Coupled Horizontal And Rocking Vibration Of Block Foundations, Sanjeev Kumar, Shamsher Prakash Apr 1995

Coupled Horizontal And Rocking Vibration Of Block Foundations, Sanjeev Kumar, Shamsher Prakash

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

The computation of coupled response of block foundations subjected to a constant magnitude harmonic horizontal force or moment or both, is very important for the design of block foundations. Mathematical relationships for computing response of rigid block foundations using the elastic half-space method lite available but are not in an easily understandable format. More over relationships available for embedded foundation are for the case when both horizontal force and moment are acting on the foundation. To extract the solution for the case when either horizontal force or moment alone is acting from the existing relationships is extremely difficult, if not …

Go to article

The Northridge Earthquake Of 1994: Ground Motions And Geotechnical Aspects, M. K. Yegian, G. V. Ghahraman, G. Gazetas, P. Dakoulas, N. Makris Apr 1995

The Northridge Earthquake Of 1994: Ground Motions And Geotechnical Aspects, M. K. Yegian, G. V. Ghahraman, G. Gazetas, P. Dakoulas, N. Makris

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

Following the January 1994 Northridge Earthquake in Southern California, the authors traveled to Los Angeles and surveyed the earthquake damage region. Subsequently, seismologic, geologic and ground motion data were compiled and evaluated. This paper presents our observations and evaluation of: geologic and soil effects; soil-structure interaction; liquefaction; slope failures and rock slides; and ground deformations.

Go to article

Performance Of Shored Earth Retaining Systems During The January 17, 1994, Northridge Earthquake, Marshall Lew, Ebrahim Simantob, Martin B. Hudson Apr 1995

Performance Of Shored Earth Retaining Systems During The January 17, 1994, Northridge Earthquake, Marshall Lew, Ebrahim Simantob, Martin B. Hudson

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

The performance of several temporary deep shored earth retaining systems during the January 17, 1994 Northridge earthquake in Southern California is documented. These shoring systems ranged from 30 to 70 feet in depth and were subjected to severe ground motions with little deflection or distress.

Go to article

Northridge Earthquake — Van Norman Complex Ground Movement, C. A. Davis, J. P. Bardet Apr 1995

Northridge Earthquake — Van Norman Complex Ground Movement, C. A. Davis, J. P. Bardet

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

The January 17, 1994, Northridge Earthquake severely shook the Van Norman Complex, in the northern San Fernando Valley. Located in the nearfield, over the vicinity of the ruptured fault, the Van Norman Complex was subjected to many types of ground movements, including strong ground motions, tectonic displacements, ground deformation of natural soil deposits, and deformation of embankments and other engineered fills. The complex provides a well-documented case of how these various types of ground movements interact and their effects on engineered facilities. Throughout the complex, sand boils, liquefaction induced lateral spreading, and ground cracks were observed. Eleven water retaining embankments, …

Go to article

Ground Motions From The Northridge Earthquake, Susan W. Chang, Jonathan D. Bray, Raymond B. Seed Apr 1995

Ground Motions From The Northridge Earthquake, Susan W. Chang, Jonathan D. Bray, Raymond B. Seed

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

The magnitude, duration and frequency content of ground motions from the Northridge Earthquake are analyzed and compared to predictive relationships typically used in engineering design and to the 1994 Uniform Building Code. The effect of geologic conditions on localized damage patterns is shown to be important for this earthquake, even though many of the sites within the affected region are stiff soil sites classified as UBC sites S1 or S2.

Go to article

Significance Of The Velacs Project To The Solution Of Boundary Value Problems In Geotechnical Engineering, K. Arulanandan, M. Manzari, X. Zeng, M. Fagan, R. F. Scott, T. S. Tan Apr 1995

Significance Of The Velacs Project To The Solution Of Boundary Value Problems In Geotechnical Engineering, K. Arulanandan, M. Manzari, X. Zeng, M. Fagan, R. F. Scott, T. S. Tan

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

The VELACS project was conducted in order to improve existing methods for the analysis of the consequences of soil liquefaction. The project showed that centrifuge studies are repeatable only under carefully controlled conditions. Most procedures were able to predict the onset of liquefaction in contractive soils, but only effective stress based fully coupled nonlinear procedures were able to predict deformations due to liquefaction· None of the currently available procedures could simulate the behavior of dilative soils adequately. Problems were attributed to improper constitutive model implementation and inadequate calibration. An example to evaluate the behavior of a flow slide observed in …

Go to article

Deformation Characteristics Of Soils And Soft Rocks Under Monotonic And Cyclic Loads And Their Relationships, Fumio Tatsuoka, Diego Lo Presti, Yukihiro Kohata Apr 1995

Deformation Characteristics Of Soils And Soft Rocks Under Monotonic And Cyclic Loads And Their Relationships, Fumio Tatsuoka, Diego Lo Presti, Yukihiro Kohata

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

For a wide variety of geomaterials, cohesionless and cohesive soils and sedimentary soft rocks and cement-mixed soils, the importance and advantages of measuring the deformation characteristics accurately and continuously for a strain range from less than 0.001 % to several % by a single static test using a single specimen are demonstrated. It is also shown that the deformation characteristics at strains of less than about 0.001 % is essentially elastic and the elastic stiffness values evaluated under static (monotonic and cyclic) and dynamic (fast cyclic) loading conditions are the same from the engineering point of view. It is discussed …

Go to article

The Evolution Of Geotechnical Earthquake Engineering Practice In North America: 1954-1994, W. D. Liam Finn, R. H. Ledbetter, W. F. Marcuson Iii Apr 1995

The Evolution Of Geotechnical Earthquake Engineering Practice In North America: 1954-1994, W. D. Liam Finn, R. H. Ledbetter, W. F. Marcuson Iii

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

This paper traces the evolution of geotechnical earthquake engineering practice in North America from 1954 to 1994. The development of the state-of-the-art has been shaped strongly by four areas of practice: assessment of seismic hazard, estimation of liquefaction potential, seismic response analysis of earth structures and seismic safety evaluation and remediation of existing dams with potentially liquefiable zones. Evolution of practice in each of these areas will be traced and the current state-of-the-art evaluated. Present capabilities in practice will be illustrated by examples from the areas of seismic response of dams, liquefaction potential and seismic safety evaluation and remediation of …

Go to article

Liquefaction-Induced Lateral Ground Displacement, T. Leslie Youd Apr 1995

Liquefaction-Induced Lateral Ground Displacement, T. Leslie Youd

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

Ground displacements generated by liquefaction-induced lateral spread are a severe threat to engineered construction. During past earthquakes, lateral spread displacements have pulled apart or sheared shallow and deep foundations of buildings, severed pipelines and other structures and utilities that transect the ground displacement zone, buckled bridges or other structures constructed across the toe, and toppled retaining walls, bulkheads, etc. that lie in the path of the spreading ground. This paper presents a method for estimating probable free-field lateral displacements at sites susceptible to liquefaction. Free-field ground displacements are those that are not impeded by structural resistance, ground modification, or a …

Go to article

Recent Advances In Centrifuge Modeling Of Seismic Shaking, Bruce L. Kutter Apr 1995

Recent Advances In Centrifuge Modeling Of Seismic Shaking, Bruce L. Kutter

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

This "State-of-the-Art" paper focuses primarily on aspects of dynamic centrifuge modeling related to simulation of earthquake effects. New shaker mechanisms and model containers are described and soil- container-shaker interaction is discussed. Progress in dealing with scale effects such as particle size, rate dependent material properties and conflicts in dissipation and generation time scale factors is also described. Issues related to repeatability and value of model testing are also discussed.

Go to article

First Prev Next Last