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

Engineering Commons™

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

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 172831 - 172860 of 194021

Full-Text Articles in Engineering

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

Finite Element Method For Love Wave Dispersion In Soils, T. D. Xia, S. M. Wu Apr 1995

Finite Element Method For Love Wave Dispersion In Soils, T. D. Xia, S. M. Wu

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

The secular equation of Love wave is conducted by using combined finite element method and semi-infinite element method (or analytical method) in this paper. The formulation of calculating displacement distributions is also generated. The soils can be more complicate than analytical method. The results indicate that the presented method is more advantageous than analytical method. Some numerical examples are employed to illustrate its applicability and corresponding accuracy.

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

Elastic Models Of Rock Due To Explosion Pressures, Sanga Tangchawal Apr 1995

Elastic Models Of Rock Due To Explosion Pressures, Sanga Tangchawal

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

Basic theories of wave pulse initiated from conventional blasting were reviewed. Mechanics of various stress wave forms of explosion pressure were proved. A new suggested solution of displacement potential by Rinehart instead of Sharpe or Duvall's suggestion, was used to find the optimum solution. From the mathematical research models, in which they were written as a package program in C language and used Microsoft visual basic as user interface, they proved that a typical cylindrical charge explosion in a bench may take on some of the characteristics of a concentrated charge explosion.

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

The Effect Of The Produced Vibrations By The Urban Electric Train On The Fillings Of Pumiceous Soils, E. Padilla Apr 1995

The Effect Of The Produced Vibrations By The Urban Electric Train On The Fillings Of Pumiceous Soils, E. Padilla

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

The paper presents the results of a study realized in Guadalajara, capital city of the State of Jalisco, in Mexico, in which it proves that the vibrations produced by the operation of the urban electric train were one of the causes of settlements presented in a habitational zone. These settlements produced very several damages to more of 30 houses. To obtain this conclusion, geotechnical studies, dynamic characterization of subsoil and laboratory tests that included the use of a shake table were realized. With the information analysis, were obtained settlement predictions between 0.035 y 0.135 m.

Go to article

Vibrations Caused By Pile Driving, P. J. Moore, J. R. Styles, Wing-Hing Ho Apr 1995

Vibrations Caused By Pile Driving, P. J. Moore, J. R. Styles, Wing-Hing Ho

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

Ground vibrations caused by impact were measured at two sites; one consisting of sand and the other of clay. Measurements were made at various radial distances from the impact location. The impact was produced by a weight falling either on to a plate or on to a rod partly driven into the ground, the latter case simulating pile driving on a small scale. When expressed in terms of scaled energy, the measured peak particle velocities were in reasonable agreement with some of the published data for clay sites but the agreement was poorer for sand sites. Several theoretical expressions were …

Go to article

Sliding Base Isolation System For Unreinforced Buildings, M. Tehranizadeh Apr 1995

Sliding Base Isolation System For Unreinforced Buildings, M. Tehranizadeh

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

The Concept of isolating structures from the effects of ground shaking has been discussed for many years. Its practical application was delayed until the successful development has been made. One of the easiest and lowest cost of base isolation system is the sliding or pure friction type that can be used for unreinforced forced masonry bearing wall building. This type of building are very common in different parts of Iran. Preliminary studies have indicated that the represented system for small buildings situated in the seismic region works very well.

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

Experimental And Numerical Investigation On Vibration Screening By In-Filled Trenches, S. Ahmad, J. Baker, J. Li Apr 1995

Experimental And Numerical Investigation On Vibration Screening By In-Filled Trenches, S. Ahmad, J. Baker, J. Li

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

In-filled concrete and soil-bentonite trenches have been used in practice for many years as wave barriers to reduce transmission of moderate to high frequency ground vibrations generated by machine foundations or traffic. An experimental investigation on the influence of various geometrical and material parameters on vibration screening effectiveness of in-filled barriers has been conducted. The experimental data are compared with numerical (BEM) Solutions as well as with design formulas of Ahmad and Al-Hussaini (1991).

Go to article

Screening Of Rayleigh Waves By Open Trenches, E. Conte, G. Dente Apr 1995

Screening Of Rayleigh Waves By Open Trenches, E. Conte, G. Dente

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

This paper presents results of a numerical study on the effectiveness of open trenches in reducing the ground vibration caused by propagating Rayleigh waves. The analysis is performed in the frequency domain and under conditions of plane strain using the Boundary Element Method. The soil is modelled as a homogeneous isotropic linear elastic half space. In order to represent the screening effect due to the installation of the barrier, the index ER is introduced. ER is defined as the ratio of the rate of energy transmission over the area to be protected in the presence of the trench and that …

Go to article

Dynamic Tests Of Foundations With Explosives, V. K. Lekarkin, A. G. Wilfand, D. D. Akhmedov, F. F. Zekhniev, B. B. Zukhurdinov Apr 1995

Dynamic Tests Of Foundations With Explosives, V. K. Lekarkin, A. G. Wilfand, D. D. Akhmedov, F. F. Zekhniev, B. B. Zukhurdinov

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

The dynamic tests results of bearing capacity of bases disposed of foundation on the tampered out trenches in subsiding soils fulfilled by means of explosions are represented. The main principles are stated which concern the dynamical lasting methods of the "soil-structure" system in subsiding soils by the modelled seismic load fulfilled by means of explosions; the principles concern the analysis of results of dimensions. The functional scheme and the description of work of the device for automatic controlling the seismic explosive load are represented.

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

Evaluation Of Man-Made Ground Vibrations, Xian Jian Yang Apr 1995

Evaluation Of Man-Made Ground Vibrations, Xian Jian Yang

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

The evaluation method of the man-made ground vibration and its formula are reviewed in the paper. The author's formula presented the possibility to solve the Vibration in near source due to the body wave from varied sources. The ground Vibration sources, such as traffic, pile driving etc. and the effects of the embedded source are involved as well. The parameters of the soil energy attenuation and the geometrical attenuation presented have been examined by National Standard Committee of CHINA in 1994. The case histories on varied testing site and vibrating effects are described.

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

Control Of Vertical Nonlinear Vibrations Of Foundations, M. Abdel-Rohman, H. Al-Sanad Apr 1995

Control Of Vertical Nonlinear Vibrations Of Foundations, M. Abdel-Rohman, H. Al-Sanad

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

Sandy soil behaves nonlinearly which affects on the vibration of machine foundations. In order to control the foundation response, damping can be introduced using tuned mass dampers. It is shown the foundation nonlinear vertical response using two different dynamic soil models, and the control of the response by linking linear or nonlinear tuned mass dampers to the foundation.

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

Discussions And Replies — Session Xii, Multiple Authors Apr 1995

Discussions And Replies — Session Xii, Multiple Authors

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

No abstract provided.

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

A New Scenario Earthquake For Southern California Based On The January 17, 1994, Northridge Earthquake, W. W. Hays Apr 1995

A New Scenario Earthquake For Southern California Based On The January 17, 1994, Northridge Earthquake, W. W. Hays

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

Prior to the M 6.8 Northridge, California, earthquake, the two principal scenarios for Southern California were based on a recurrence of a great earthquake (M 8.25) on the San Andreas Fault system and a moderate earthquake (M 6.5) on the Newport-Inglewood fault zone. Like the January 17, 1994, Northridge earthquake, the new scenario event--a blind thrust fault beneath Los Angeles--is expected to generate very high levels of ground shaking (acceleration, velocity, displacement, spectral response) in the epicentral region, trigger ground failure over a wide area; cause extensive damage to the built environment; and test all aspects of the earthquake risk …

Go to article

Solid Waste Landfill Performance During The 1994 Northridge Earthquake, A. J. Augello, J. D. Bray, R. B. Seed, N. Matasovic, E. Kavazanjian Jr. Apr 1995

Solid Waste Landfill Performance During The 1994 Northridge Earthquake, A. J. Augello, J. D. Bray, R. B. Seed, N. Matasovic, E. Kavazanjian Jr.

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

The performance of 22landfills in the Los Angeles area during the January 17, 1994 Northridge earthquake has been investigated. Observations of damage at these landfills indicate that the overall performance of solid waste landfills was encouraging. None of the surveyed landfills showed any signs of major damage. However, one geosynthetic-lined landfill experienced two tears in the geomembrane liner. Most landfills within 30 km of the zone of energy release experienced some form of cracking in the soil cover. Beyond approximately 40 km from the zone of energy release, little to no damage was observed.

Go to article

The Performance Of Hillside Fills During The Northridge Earthquake, David J. Mcmahon, Alan Kropp, Jonathan P. Stewart, Jonathon D. Bray Apr 1995

The Performance Of Hillside Fills During The Northridge Earthquake, David J. Mcmahon, Alan Kropp, Jonathan P. Stewart, Jonathon D. Bray

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

Many hillside fills located in the Santa Monica, Santa Susana, and San Gabriel Mountains were damaged during the 1994 Northridge Earthquake. While no deaths have been attributed to fill movement, on the order of tens of millions of dollars in property damage was caused by fill movements which typically involved less than about 7.5cm (3 inches) of localized displacement. Some of the damage was induced by permanent deformations of underlying native materials, but most appears to have resulted from ground failure or ground shaking phenomena associated directly with the fill materials. These phenomena include cyclic compaction, lurching, and amplification of …

Go to article

Northridge (California) Earthquake: Unique Ground Motions, Mehmet Celebi Apr 1995

Northridge (California) Earthquake: Unique Ground Motions, Mehmet Celebi

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

The Northridge (California) earthquake of 17 January 1994 generated numerous strong-motion records that are unique because they have: (a) very high peak accelerations and (b) long-duration pulses. Using digitized data available to date, the significant aspects of the strong-motions are preliminarily reviewed and their impact on earthquake engineering are discussed.

Go to article

First Prev Next Last