Analyses of earthquake ground motions at Japanese sites

1970 ◽  
Vol 60 (6) ◽  
pp. 2057-2070
Author(s):  
F. W. Kiefer ◽  
H. Bolton Seed ◽  
I. M. Idriss
Keyword(s):  
Ground Motions ◽  
Ground Surface ◽  
Response Spectra ◽  
Soil Conditions ◽  
Mass Analysis ◽  
Lumped Mass ◽  
Ground Response ◽  
Maximum Acceleration ◽  
Soil Layers ◽  
Local Soil

Abstract Ground motions at several Japanese sites are evaluated using recently-developed techniques which involve assessing the base-rock motion at the site due to an earthquake, establishing the properties of the overlying soil layers, and computing the response at the ground surface using a lumped-mass-analysis procedure. The maximum acceleration and the form of the response spectra for ground motions recorded at the several sites agree reasonably well with the computed values. It is concluded that where the soil conditions can be reliably determined, the analytical procedures offer good promise as a means of considering the effects of local soil conditions in the prediction of ground response.

Strong ground motions recorded during earthquakes of May the 11th and 19th, 1962 in Mexico City

1964 ◽  
Vol 54 (1) ◽  
pp. 209-231
Author(s):  
Leonardo Zeevaert
Keyword(s):  
Mexico City ◽  
Ground Motions ◽  
Soft Clay ◽  
Response Spectra ◽  
The Other ◽  
Soil Conditions ◽  
Strong Ground Motions ◽  
Multistory Building ◽  
Local Soil ◽  
Strong Ground

abstract The ground accelerations during the earthquakes of May 11 and 19, 1962 were recorded in Mexico City on a soft clay bed that was formerly the floor of an old lake. Records were obtained from two accelerometers, one instrument was located in the basement of a multistory building and the other was located in a nearby park. Response spectra of the ground motions are presented and analysis is made of the local soil conditions with the view to explaining the characteristics of the spectrums.

The Mexico Earthquake of September 19, 1985—Relationships between Soil Conditions and Earthquake Ground Motions

1988 ◽  
Vol 4 (4) ◽  
pp. 687-729 ◽  
Author(s):  
H. B. Seed ◽  
M. P. Romo ◽  
J. I. Sun ◽  
A. Jaime ◽  
J. Lysmer
Keyword(s):  
Shear Wave ◽  
Mexico City ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Ground Motions ◽  
Probabilistic Approach ◽  
General Nature ◽  
Soil Conditions ◽  
Ground Response ◽  
Local Soil

Comparisons are presented between the characteristics of ground motions at five sites underlain by clay at which ground motions were recorded in Mexico City in the earthquake of September 16, 1985 and for which analyses of ground response have been made, based on the measured properties of soils and the motions recorded on hard formations at the National University of Mexico. It is shown that the ground response in areas of Mexico City underlain by clay is extremely sensitive to small changes in the shear wave velocity of the clay and it is suggested that a probabilistic approach which allows for uncertainties in shear wave velocity measurements and in the characteristics of the motions on the hard formations is desirable to assess these effects. Based on the results of such an approach it is concluded that simple ground response analyses can provide very useful data for engineering assessments of the effects of local soil conditions on the characteristics of ground motions likely to develop at sites underlain by soft clays, and that the use of these procedures also provides a useful basis for estimating the general nature of the ground motions in the extensive heavy damage zone of Mexico City in the 1985 earthquake.

Modification of seismograph records for effects of local soil conditions

1972 ◽  
Vol 62 (6) ◽  
pp. 1649-1664 ◽  
Author(s):  
P. Schnabel ◽  
H. Bolton Seed ◽  
J. Lysmer
Keyword(s):  
San Francisco ◽  
Ground Surface ◽  
Soil Conditions ◽  
Local Soil ◽  
Geological Conditions ◽  
Soil Deposits ◽  
Time Histories ◽  
Seismic Records ◽  
Local Soil Conditions ◽  
Good Agreement

abstract A procedure for modifying the time histories of seismic records for the effect of local soil conditions is presented. The method is based on a conventional one-dimensional wave-propagation approach with equivalent linear soil properties, extended to practical use for transient motions through the Fast Fourier technique. The validity of the approach is tested against the motions recorded at four soil sites and one rock site during the 1957 San Francisco earthquake. The good agreement between the computed and recorded values indicates that rock motions can be computed from motions recorded on soil deposits, and that the computed rock motions in turn can be used to predict the motion that would have been recorded under different soil and geological conditions. The method is also used to evaluate the probable rock motions in the vicinity of El Centro in the earthquake of 1940 and the ground surface motions that could have been developed on various soil conditions in the same general area.

Evaluation of SCEC CyberShake Ground Motions for Engineering Practice

2019 ◽  
Vol 35 (3) ◽  
pp. 1311-1328 ◽  
Author(s):  
Ganyu Teng ◽  
Jack Baker
Keyword(s):  
Los Angeles ◽  
Ground Motion ◽  
Ground Motions ◽  
Response Spectra ◽  
Building Design ◽  
Empirical Models ◽  
Soil Conditions ◽  
Engineering Practice ◽  
Ground Motion Selection ◽  
Promising Source

This paper evaluates CyberShake (version 15.12) ground motions for potential application to high-rise building design in the Los Angeles region by comparing them against recordings from past earthquakes as well as empirical models. We consider two selected sites in the Los Angeles region with different underlying soil conditions and select comparable suites of ground motion records from CyberShake and the NGA-West2 database according to the ASCE 7-16 requirements. Major observations include (1) selected ground motions from CyberShake and NGA-West2 share similar features, in terms of response spectra and polarization; (2) when selecting records from Cyber-Shake, it is easy to select motions with sources that match the hazard deaggregation; (3) CyberShake durations on soil are consistent with the empirical models considered, whereas durations on rock are slightly shorter; (4) occasional excessive polarization in ground motion is produced by San Andreas fault ruptures, though those records are usually excluded after the ground motion selection. Results from this study suggest that CyberShake ground motions are a suitable and promising source of ground motions for engineering evaluations.

Analyses of ground motions at Union Bay, Seattle during earthquakes and distant nuclear blasts

1970 ◽  
Vol 60 (1) ◽  
pp. 125-136 ◽  
Author(s):  
H. Bolton Seed ◽  
I. M. Idriss
Keyword(s):  
Ground Motions ◽  
Ground Surface ◽  
Glacial Till ◽  
Lumped Mass ◽  
Time Histories ◽  
Variable Damping ◽  
Different Depths ◽  
Clay Layers ◽  
High Degree ◽  
Strain Dependent

abstract Recordings of accelerations at three different depths within the soil profile at Union Bay were obtained during a mild nearby earthquake and three distant nuclear blast events. These recordings were made by instruments which had been placed in peat 10 feet below the ground surface, in clay 61 feet below the ground surface and in glacial till 105 feet below the ground surface. Accelerations in the EW, NS and vertical directions were recorded simultaneously at these three depths. Using an equivalent linear variable damping lumped-mass solution, incorporating strain-dependent material properties for the peat and clay layers, the motions throughout the deposits were computed. The recorded accelerations in the glacial till were used as input base motion. Comparisons of the time histories of accelerations, maximum accelerations and spectral values of the motions recorded during the nearby earthquake with the corresponding computed motions indicated a high degree of agreement. The maximum accelerations recorded during the distant nuclear blast events also compared well with the computed accelerations.

ENGINEERING CHARACTERISTICS AND EARTHQUAKE RESPONSE ANALYSIS OF GROUND

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Haruyuki Yamamoto ◽  
Munkhunur Togtokhbuyan
Keyword(s):  
Shear Modulus ◽  
Ground Surface ◽  
Response Analysis ◽  
Soil Profiles ◽  
Lumped Mass ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Natural Period ◽  
Soil Deposits ◽  
Computational Procedures

One-dimensional layered soil lumped mass ground response analysis was conducted for the representative site in Ulaanbaatar, Mongolia. The surficial geology of the site is predominantly composed of the gravely and sandy soil typical of this region in the central part of Ulaanbaatar. The natural period of soil profiles needs to be investigated under several circumstances. For example, these parameters-based study has indicated that damage due to earthquakes occurs when the natural periods, T1 and T2, of the ground are closer to that of a superstructure. Various computational procedures or methods have been proposed for this kind of the ground response analysis. In this paper, the numerical analysis method such as the lumped mass method within eigenvalue analysis is used to determine the natural periods of the ground. The ground surface, soil deposits, and bedrock are assumed to be horizontal. The soil deposits are subjected to shear deformation such as shear modulus, G, on the other hand, excitation of vibration could be a shear modulus on each layer. As well as to determine an engineering bedrock depth in the site, the methodology that is utilized in this paper is focused on the use of the correlation between SPT-N value and soil elastic Young's modulus, E, in the soil profiles, and used over 100 boreholes data with SPT-N values in the vicinity of Ulaanbaatar.

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