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Articles 181 - 201 of 201
Full-Text Articles in Civil and Environmental Engineering
Predicting Pore Pressure And Applications To Complex Loading Problems, Dwight A. Sangrey, Vincent P. Lascko
Predicting Pore Pressure And Applications To Complex Loading Problems, Dwight A. Sangrey, Vincent P. Lascko
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Methods for predicting and modeling the pore pressure response when soils are subjected to cyclic loading are described. These predictions include both the limiting states of pore pressure and the intermediate stages of development as a function of number of cycles. Applications of pore pressure prediction in effective stress methods are illustrated for a group of problems including sequencing of irregular loading, degradation of stress-strain modulus, volume changes and strength changes.
Response Of Non-Saturated Soil To Cyclic Loading, R. C. Chaney, H. Y. Fang
Response Of Non-Saturated Soil To Cyclic Loading, R. C. Chaney, H. Y. Fang
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The response of partially saturated and dry sand materials under cyclic loading is controlled by the compressibility of the pore fluid. For dry sand the limiting axial and volumetric strain occurs within 5 to 15 cycles of load application and is a function of the number of cycles of cyclic stress, relative density, and effective consolidation pressure. In addition the axial strain is shown to be independent of the consolidation stress ratio for loose sand and decreases with increasing consolidation stress ratio for dense sand under a constant cyclic stress.
Dilation Angle And Liquefaction Potential, Y. P. Vaid, P. M. Byrne, J. M. O. Hughes
Dilation Angle And Liquefaction Potential, Y. P. Vaid, P. M. Byrne, J. M. O. Hughes
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Most of our understandin9 of the liquefaction phenomenon has come from laboratory tests. It would be desirable to express liquefaction resistance in terms of a parameter which can be measured both in the laboratory and in the field. It is proposed that the dilation angle or expansion rate of the sand is such a parameter. It is readily measured in the laboratory from drained simple shear or triaxial tests and in the field from self boring pressuremeter tests. Based on laboratory tests on Ottawa sand a chart is presented for estimating the liquefaction resistance of saturated sands in terms of …
Macroscopic Approach To Soil Liquefaction, Zhong-Qi Wang
Macroscopic Approach To Soil Liquefaction, Zhong-Qi Wang
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
In view of the fact that microscopic liquefaction cannot be equated with the macroscopic one; further, owing to the unsolved difficulties in taking undisturbed samples of sand end in performing laboratory tenting of liquefaction, the author has tried to search after new practical way to assess soil liquefaction potential by macroscopic approach. This paper presents a preliminary study winch can coordinate each other with the laboratory microscopic procedures so as to make more reliable prediction to liquefaction potential and assessment of its seismic effect.
In-Situ Undisturbed Sand Sampling By Radial Freezing For Liquefaction Analysis, R. Da Rolt, L. Lojelo, F. Muzzi, G. Spat
In-Situ Undisturbed Sand Sampling By Radial Freezing For Liquefaction Analysis, R. Da Rolt, L. Lojelo, F. Muzzi, G. Spat
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The authors experimented in laboratory that if radial freezing with free drainage is performed under an effective confining pressure of 100 kPa only an increase of the order of 0.5% of volumetric strain takes place going from the unfrozen to the frozen condition. The sample comes back to the original dimension after thawing. The displacements of the sample were measured by radiographs of a lead shot network properly built inside the sample. The technique suggested by Yoshimi and al. (1977) to freeze in situ a column of saturated sands was also verified and optimized in laboratory by simulating in a …
Analysis Of Rigid Retaining Walls During Earthquakes, Shamsher Prakash
Analysis Of Rigid Retaining Walls During Earthquakes, Shamsher Prakash
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Retaining walls experience changed pressures and undergo displacements as well during earthquakes. Both the questions have been discussed in detail in this paper. Increments in active earth pressures have been correlated with peak ground velocity and a method to compute seismic coefficient to be used in the Mononabe method has been proposed. The question of point of application of the dynamic increment has also been examined in detail. There are three methods to compute displacements of rigid retaining walls, a) based on Newmark's approach of a sliding block, b) computation of translation only and c) computation of displacements due only …
Effect Of Vibration On Pile Uplift Capacity, P. J. Moore, J. P. Piper
Effect Of Vibration On Pile Uplift Capacity, P. J. Moore, J. P. Piper
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
An experimental and theoretical study has been carried out to examine the effects of vibration frequency and amplitude as well as magnitude of static applied load on the uplift capacity of piles driven into a sandy soil. The theoretical solution was developed using a lumped parameter model with viscous damping. The results, both theoretical and experimental, indicate that the displacement amplitude required to cause uplift failure of the pile, decreases as the vibration frequency increases. This trend was shown to be significantly dependent upon the natural frequency of the pile-soil system and to a lesser degree, upon the damping ratio. …
Dynamic Analysis Of Foundations For Heavy Duty Diesel Engines, N. S. V. Kameswara Rao
Dynamic Analysis Of Foundations For Heavy Duty Diesel Engines, N. S. V. Kameswara Rao
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Coupled motion analysis of Machine-Foundation-Soil systems subjected to periodic dynamic forces and moments which are of general nature (both in amplitudes and periods) has been carried out using Fourier analysis and numerical techniques. Free vibration as well as forced vibration analysis in all the coupled and uncoupled modes of the system has been presented. The procedure is illustrated in the case of an eight cylinder heavy duty diesel engine generator assembly and results have been graphically shown in terms of frequency ratios and maximum steady state responses in the all the relevant modes of vibration.
Soil-Pile Interaction In Vertical Vibration, Y. Gyoten, K. Mizuhata, T. Fukusumi, H. Nozoe, T. Inoue, T. Mizuno
Soil-Pile Interaction In Vertical Vibration, Y. Gyoten, K. Mizuhata, T. Fukusumi, H. Nozoe, T. Inoue, T. Mizuno
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This paper deals with the theoretical study concerning soil-pile interaction in vertical vibration for both the floating pile and the pile group. The analysis is made by applying the elastic wave theory to the viscoelastic layer overlying on the rigid bedrock. Further, the displacement responses of the pile and the complex stiffness at the pile head subjected to the harmonic excitation at the top of the pile are obtained for various parameters.
Stiffness Coefficients For Embedded Footings, L. S. Chickanagappa
Stiffness Coefficients For Embedded Footings, L. S. Chickanagappa
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Mindlin’s theory and Steinbrenner’s approximation are used to evaluate the static stiffness coefficients for embedded footings subjected to vertical oscillations. The footing is assumed to be embedded in an elastic layer underlain by a rigid base. The solution presented is simple and is amenable to hand calculations. It compares well with other rigorous solutions, in the analysis presented in the paper the shape of the footing can be easily taken into account. The method gives a solution which lies between the finite element solution and the rigorous closed form solutions.
Session 4: Discussion And Replies, Multiple Authors
Session 4: Discussion And Replies, Multiple Authors
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
No abstract provided.
Free Response Of Shells On Flexible Foundation, R. M. Belkune, J. C. Vyas
Free Response Of Shells On Flexible Foundation, R. M. Belkune, J. C. Vyas
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
Free response of axisymmetric shells resting on flexible foundation in their asymmetric modes is studied using Finite Elements based on harmonic formulation. Influence of various parameters, such as subgrade modulus, proximity of boundary, density ratio, shear wave velocity, embedment of structure and depth of flexible foundation., on free response is studied. Axisymmetric interface element with harmonic functions is developed and introduced between the raft slab and foundation media.
Dynamic And Earthquake Geotechnical Centrifuge Modelling, A. N. Schofield
Dynamic And Earthquake Geotechnical Centrifuge Modelling, A. N. Schofield
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This state of art review discusses scaling principles for dynamic and earthquake geotechnical centrifuge models that have been known for many years, and shows how the new emphasis on modelling of models using reconstituted soil helps to reduce the difficulties of verification of these principles. It is suggested that models made of reconstituted soil can exhibit a wide range of behavior that is important in the field. In particular it is suggested that liquefaction and cracking are related phenomena which can both be modelled.
Offshore Earthquake Geotechnology — First Part, P. B. Selnes
Offshore Earthquake Geotechnology — First Part, P. B. Selnes
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
This first part of the paper outlines the problems encountered offshore compared to onshore. The most important difference is the presence of water which changes the dynamic behavior of structures, introduces new forces, complicates the soil investigation and visual site inspection, and changes the characteristics of the earthquake ground motion. Furthermore, the structures offshore may be much larger than most onshore facilities, and other environmental loads may act simultaneously with an earthquake.
Earthquake Resistance Of A Rockfill Dam, C. Bossoney, M. Balissat, E. G. Prater, J. Studer, N. Zingg
Earthquake Resistance Of A Rockfill Dam, C. Bossoney, M. Balissat, E. G. Prater, J. Studer, N. Zingg
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
The paper describes the investigation of the seismic safety of a 131 m high rock fill dam presently under construction across the Rio Chixoy in Guatemala. The dam is located in a region of high seismicity the recently active Motagua fault being only 40 km distant. Due to the possibility of high peak ground accelerations it was considered necessary to conduct a full dynamic analysis, which was carried out in stages following the Seed-Lee-Idriss method, the latter being modified where it was deemed necessary.
Pore Pressure Analysis For An Earth Dam During Earthquake, R. C. Sonpal, A. A. Dave
Pore Pressure Analysis For An Earth Dam During Earthquake, R. C. Sonpal, A. A. Dave
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
An analytical study of the pattern of variation in the pore pressures within an embankment during earthquake, based upon seismic analysis by the rigid body response method and by the elastic body response method using ICL 1901 A computer is presented herein. The pore pressure contours before and during an earthquake are presented for an upstream slope of Tapar dam situated in seismically active zone in West India.
Session 7: Moderator's Report, W. F. Marcuson Iii
Session 7: Moderator's Report, W. F. Marcuson Iii
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
No abstract provided.
Measurements Of Lnsitu Pore Water Pressures During Earthquakes, K. Ishihara
Measurements Of Lnsitu Pore Water Pressures During Earthquakes, K. Ishihara
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
By installing several sets of piezometers and a seismograph in a recently reclaimed sand deposit on Ohgishima Island near Tokyo, Japan, an attempt was made to monitor pore water pressures as well as horizontal accelerations during earthquakes. The limited data obtained thus far have indicated that virtually no pore water could build up in the loose sand deposit with a small scale shaking having a maximum horizontal acceleration of 45 gal on the ground surface.
Zonation Of Central U. S. Earthquake Sources, G. L. Hempen, M. J. Klosterman, B. H. Moore, John D. Rockaway, Gerald B. Rupert
Zonation Of Central U. S. Earthquake Sources, G. L. Hempen, M. J. Klosterman, B. H. Moore, John D. Rockaway, Gerald B. Rupert
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
A variety of analyses are utilized in developing potential earthquake ground shaking at a specific location. Geological procedures for estimating causes of earthquakes are fundamental to the prediction of ground motions. Evaluations of geologic factors compliment mathematical assessments of seismological data. Earthquake potential in the Central United States is predicted using the concept of seismic source zones due to the difficulty of determining active faults. Resolution of these geographic source zones is dependent upon knowledge of historic seismicity, pertinent geologic features, and causative tectonics. Regardless of the method used to delineate source zones, these zones must be geologically and seismologically …
Session 9: Moderator's Report, Umesh Chandra
Session 9: Moderator's Report, Umesh Chandra
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
No abstract provided.
Session 9: Closing Remarks, T. Kuppusamy
Session 9: Closing Remarks, T. Kuppusamy
International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics
No abstract provided.