Article records
https://feeds.library.caltech.edu/people/Jennings-P-C/article.rss
A Caltech Library Repository Feedhttp://www.rssboard.org/rss-specificationpython-feedgenenFri, 12 Apr 2024 23:42:34 +0000Vibration and soil-structure interaction tests of a nine-story reinforced concrete building
https://resolver.caltech.edu/CaltechAUTHORS:20140801-155528258
Authors: {'items': [{'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}, {'id': 'Kuriowa-J-H', 'name': {'family': 'Kuriowa', 'given': 'Julio H.'}}]}
Year: 1968
The Millikan Library Building, a nine-story reinforced concrete shear-wall structure at the California Institute of Technology, was tested dynamically by means of two eccentric mass vibration generators located on the ninth floor. The response levels ranged up to a maximum acceleration of 0:02 g. The natural periods of vibration, the mode shapes and the energy dissipation were measured for the first and second E-W translational modes, the N-S fundamental mode and the first torsional mode. Soil-structure interaction was investigated by measuring foundation motion and nearby soil surface movements during resonent vibrations in the N-S and E-W fundamental modes. Other tests included "man-excited" vibrations at low stress levels and a measurement of resonance of an air handling unit on the roof, which was found to magnify the roof response by a factor of 8.5.
The measured fundamental periods were short compared to typical framed structures of this height, 0.50 sec in the N-S direction, 0.66 in the E-W direction and 0.46 in torsion. These values increased roughly 3 per cent over the range of testing. The energy dissipation as measured by a viscous damping factor, varied between 0.70 and 2.00 per cent of critical. This large variation over the testing range indicates that tests at higher stresses are needed to determine the energy dissipation expected during the response to strong earthquake motions.
The soil-structure interaction measurements showed that the building responded very nearly as if fixed at the foundation; rocking contributed less than 1 per cent to the total roof motions of the structure and foundation translation about 2 per cent. Although negligible as far as the building motion is concerned, the results demonstrate the possibility of performing full-scale soil-structure interaction experiments.https://authors.library.caltech.edu/records/1khcb-sct46Calculation of response spectra from strong-motion earthquake records
https://resolver.caltech.edu/CaltechAUTHORS:20140801-162108191
Authors: {'items': [{'id': 'Nigam-N-C', 'name': {'family': 'Nigam', 'given': 'Navin C.'}}, {'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 1969
A numerical method for computing response spectra from strong-motion earthquake records is developed, based on the exact solution to the governing differential equation. The method gives a three to four-fold saving in computing time compared to a third order Runge-Kutta method of comparable accuracy. An analysis also is made of the errors introduced at various stages in the calculation of spectra so that allowable errors can be prescribed for the numerical integration. Using the proposed method of computing or other methods of comparable accuracy, example calculations show that the errors introduced by the numerical procedures are much less than the errors inherent in the digitization of the acceleration record.https://authors.library.caltech.edu/records/4v0yw-dax32Distant motions from a building vibration test
https://resolver.caltech.edu/CaltechAUTHORS:20140915-093836673
Authors: {'items': [{'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 1970
Horizontal ground motion generated by vibration tests of the nine-story Millikan Library Building on the Caltech campus was recorded on the surface of the ground in the Pasadena area at distances up to 3 miles from the building. Later it was learned that the vertical component of the motion also was recorded by the seismograph on Mt. Wilson, 6.7 miles from the Library and 4,800 ft higher in elevation. The magnitude of the acceleration varied from 2.04 × 10-^(2)g at the excitation level on the ninth floor of the building to 3.2 × 10^(-7)g at Mt. Wilson. Simple calculations show that multistory buildings are particularly well-suited for inducing large dynamic forces in the ground with relatively small equipment.https://authors.library.caltech.edu/records/sf7zy-ntm16Dynamics of building-soil interaction
https://resolver.caltech.edu/CaltechAUTHORS:20140812-110158028
Authors: {'items': [{'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}, {'id': 'Bielak-Jacobo', 'name': {'family': 'Bielak', 'given': 'Jacobo'}}]}
Year: 1973
In this study of the dynamics of building-soil interaction, the soil is modeled by a linear elastic half-space, and the building structure by an n-degree-of-freedom oscillator. Both earthquake response and steady-state response to sinusoidal excitation are examined. By assuming that the interaction system possesses n+2 significant resonant frequencies, the response of the system is reduced to the superposition of the responses of damped linear oscillators subjected to modified excitations. The results are valid even though the interaction systems do not possess classical normal modes. For the special cases of single-story systems and the first modes of n-story systems, simplified approximate formulas are developed for the modified natural frequency and damping ratio and for the modified excitation. Example calculations are carried out by the approximate and more exact analysis for one-story, two-story and ten-story interaction systems.
The results show that interaction tends to decrease all resonant frequencies, but that the effects are often significant only for the fundamental mode for many n-story structures and are more pronounced for rocking than for translation. If the fixed-base structure has damping, the effects of interaction on the earthquake responses are not always conservative, and an increase or decrease in the response can occur, depending on the parameters of the system.https://authors.library.caltech.edu/records/yej0c-ch956Comments on "Bedrock Intensity Attenuation and Site Factors from San Fernando Earthquake Records" by K. W. Campbell and C. Martin Duke
https://resolver.caltech.edu/CaltechAUTHORS:20140909-095320032
Authors: {'items': [{'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 1974
In the paper "Bedrock Intensity Attenuation and Site Factors from San Fernando
Earthquake Records," by K. W. Campbell and C. Martin Duke, which appeared in the
February, 1974 issue of the Bulletin, a correlation is made between a measure of intensity
of recorded ground accelerations and four categories of soil, classified by increasing
softness. The authors present different numerical site factors for each category and conclude
that their results are sufficiently reliable to justify their use for purposes of zoning.
The site factors and the conclusion are based mainly on the data presented in their Figure
5 and the lines of specified slope fitted by least squares to the data points. The set of lines
in their Figure 6 present the authors' idealized relation between intensity, softness of
ground, and distance from the source. The upper four lines in Figure 6 are taken from
Figure 5.https://authors.library.caltech.edu/records/4vwfs-36v87Soil-structure interaction during the San Fernando earthquake
https://resolver.caltech.edu/CaltechAUTHORS:20140812-113927162
Authors: {'items': [{'id': 'Crouse-C-B', 'name': {'family': 'Crouse', 'given': 'Charles B.'}}, {'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 1975
Accelerograms obtained at two sites during the San Fernando earthquake of 1971 were analyzed to investigate the role of soil-structure interaction, using techniques developed by Bielak and others. Analysis of the data from the site of the Hollywood Storage Building, for which data from the Arvin-Tehachapi earthquake of 1952 are also available, showed evidence of soil-structure interaction in the way the transfer functions between parking lot and basement motion decayed with increasing frequency in the two lateral directions. It is concluded also that interaction probably had a small effect on the response near the EW fundamental frequency during the San Fernando earthquake. Although theoretical and experimentally determined transfer functions are broadly similar, they do not agree in detail. The lack of good agreement for reasonable choices of the parameters of the theoretical model indicates a need for some modifications of the theory or its application, and a need for more measurements at the site.
A similar analysis showed no clear evidence of soil-structure interaction for the Millikan Library and Athanaeum buildings on the campus of the California Institute of Technology. If soil-structure interaction caused the major differences measured in the base motions of these two buildings, it is of a more complex form than that considered by present theories.https://authors.library.caltech.edu/records/ma4rn-9qv45Proceedings of the Fifth World Conference on Earthquake Engineering [Book Review]
https://resolver.caltech.edu/CaltechAUTHORS:20140912-090306574
Authors: {'items': [{'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 1975
The recently issued two-volume set of the Proceedings of the Fifth World Conference on Earthquake
Engineering consists, essentially, of all the papers presented at the last world conference held in Rome
in July of 1973. There are approximately 420 papers divided about equally between those 10 pages long
and the shorter 4-page papers. The volumes include all the papers which were issued as preprints, a few
submitted too late for preprinting, and some 30 discussions. Several of the discussions are categorized
as free discussions, and are actually additional papers. Also included in the Proceedings is a list of the
850 participants from the 45 countries represented at the conference; an index of the papers, by session;
an index of authors; and a brief section containing data about the International Association for Earthquake
Engineering, the sponsoring organization. In the same section are the brief speeches given at the
opening and closing ceremonies, administrative reports, and a few photographs. This general material
comprises 168 pages, bringing the total for the volumes to nearly 3,200 pages. The massive volumes,
3½ in thick, are well-bound in maroon fabrikoid with gold lettering. The papers are reproduced photographically
from originals supplied by the authors so there is considerable variation in typography. The
quality of both the printing and the paper is very good, however, and the legibility of text, figures and
photographs is at least equal to any of the Proceedings of previous world conferences.https://authors.library.caltech.edu/records/tzq8q-qgm09Effects of canyon topography on strong ground motion
https://resolver.caltech.edu/CaltechAUTHORS:20140826-133958379
Authors: {'items': [{'id': 'Wong-H-L', 'name': {'family': 'Wong', 'given': 'H. L.'}}, {'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'P. C.'}}]}
Year: 1975
The two-dimensional scattering and diffraction of SH waves of arbitrary angle of incidence from irregular, canyon-shaped topography is formulated in terms of an integral equation. Taking advantage of the simple boundary conditions of SH-wave problems, the method of images is applied to reduce the integral equation to one with a finite integral, which can readily be solved numerically by available methods.
The method is first applied to the analytically solved case of a cylindrical canyon to verify its accuracy, and then to two idealized cross sections based upon Pacoima Canyon to investigate the effects of topography in a more realistic case. The results of the harmonic analysis include wave amplification patterns and transfer functions for different wavelengths and for different angles of incidence. The study also includes analysis of transient motions. With the N76°W component of the Pacoima Dam accelerogram specified to occur at one point in the cross section, the effects of different angles of incidence upon the required input motion and upon the motion at several other points in the cross section were examined by calculating accelerograms and response spectra.
The effects of canyon-shaped topography are seen most prominently in the amplification patterns and transfer functions for harmonic response, wherein shielding and focusing can cause variations up to a factor of six for wavelengths comparable to, or shorter than, the canyon width. In the case of transient motions, the accelerograms at different points show significant differences, but not as large as seen in the harmonic analysis. The response spectra show the smallest differences; significant effects are confined to the higher frequencies.https://authors.library.caltech.edu/records/wfbba-t3w17A study of the apparent change in the foundation response of a nine-story reinforced concrete building
https://resolver.caltech.edu/CaltechAUTHORS:20140812-132823758
Authors: {'items': [{'id': 'Foutch-Douglas-Allen', 'name': {'family': 'Foutch', 'given': 'Douglas A.'}}, {'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 1978
Forced vibration tests of the Millikan Library building, a nine-story reinforced concrete shear-wall structure, were conducted in 1966 and 1967, before the San Fernando earthquake, and again in 1974. The measured foundation response of the structure reported for the two tests was significantly different: in the earlier tests, motion of the foundation in the N-S direction contributed only about 3 per cent to the total roof motion, whereas in the more recent tests almost 30 per cent of the roof motion was contributed by foundation compliance. A lengthening of the fundamental period of vibration of 11 per cent was also noted.
The purpose of this study is to examine the indication that the foundation response of the structure may have changed because of the earthquake. To determine whether the observed changes in foundation response are consistent with the change in natural period, two analytical models of the Millikan Library building were developed. Both of these models include the effects of foundation compliance and one includes the effects of shear deformations in the walls of the structure. The results of these simple analyses show the changes of mode shape and period observed between the two tests to be consistent.
From the analysis, and from an examination of what is thought to be minor earthquake damage at the ground floor level of the structure, the authors conclude that the most probable cause of the differences observed in the two tests is the loss of rotational and translational stiffness provided by retaining walls, concrete slabs and other stiff, but brittle elements.https://authors.library.caltech.edu/records/4xsyb-6ry17Determination of local magnitude, M_L, from strong-motion accelerograms
https://resolver.caltech.edu/CaltechAUTHORS:20140812-150325552
Authors: {'items': [{'id': 'Kanamori-H', 'name': {'family': 'Kanamori', 'given': 'Hiroo'}, 'orcid': '0000-0001-8219-9428'}, {'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 1978
A technique is presented for determination of local magnitude, M_L, from strong-motion accelerograms. The accelerograph records are used as an acceleration input to the equation of motion of the Wood-Anderson torsion seismograph to produce a synthetic seismogram which is then read in the standard manner. When applied to 14 records from the San Fernando earthquake, the resulting M_L is 6.35, with a standard deviation of 0.26. This is in good agreement with the previously reported value of 6.3. The technique is also applied to other earthquakes in the western United States for which strong-motion records are available. An average value of M_L = 7.2 is obtained for the 1952 Kern County earthquake; this number is significantly smaller than the commonly used value of 7.7, which is more nearly a surface-wave magnitude.
The method presented broadens the base from which M_L can be found and allows M_L to be determined in large earthquakes for which no standard assessment of local magnitude is possible. In addition, in instances where a large number of accelerograms are available, reliable values of M_L can be determined by averaging.https://authors.library.caltech.edu/records/zaca8-3bn14Determination of local magnitude, M_L, from seismoscope records
https://resolver.caltech.edu/CaltechAUTHORS:20140826-135433421
Authors: {'items': [{'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}, {'id': 'Kanamori-H', 'name': {'family': 'Kanamori', 'given': 'Hiroo'}, 'orcid': '0000-0001-8219-9428'}]}
Year: 1979
A method is presented for determining the local magnitude, M_L, from records from seismoscopes and similar instruments. The technique extrapolates the maximum response of the standard Wood-Anderson seismograph, which determines M_L, from the maximum response of the seismoscope. The standard deviation of the steady-state response of an oscillator subjected to white noise excitation is used to derive a relation correcting for the different periods, dampings, and gains of the two instruments. The accuracy of the method is verified by application to data from the San Fernando and Parkfield earthquakes wherein both accelerograph and seismoscope records are available from the same sites. The accelerograms are used to synthesize Wood-Anderson responses whose maxima are compared to those extrapolated from the seismoscope data. In both earthquakes, the average magnitudes and standard deviations determined by the two approaches are very nearly equal.
The method is then applied to the strong-motion data from the Managua, Nicaragua earthquake of December 23, 1972 (M_S = 6.2, mb = 5.6). A value of M_L = 6.2 is indicated from the seismoscope and accelerograph data. The next application is to the Guatemala earthquake of February 4, 1976 (M_S = 7.5, mb = 5.8). The only seismic instrumentation available for determining M_L is a seismoscope record from Guatemala City, which indicates M_L = 6.9 when a representative distance of about 35 km is used. As a final example, the records obtained during the 1906 San Francisco earthquake Formula from the Ewing duplex pendulum seismograph at Carson City, Nevada and the simple pendulum at Yountville, California are analyzed. After restoring the Carson City instrument, its period and damping were determined experimentally as were the period and damping of a similar instrument in the London Science Museum. On the basis of the strong-motion records from Carson City and Yountville, it is estimated that the local magnitude of the 1906 earthquake lies in the range Formula to 7.
The use of seismoscope data further extends the instrumental base from which M_L can be determined and allows the rapid determination of M_L in earthquakes where seismoscope data are available. The applications in this study provide further instrumental evidence for the saturation of M_L in the 7 to Formula range, with the value of 7.2 for the Kern County earthquake of 1952, the largest so far determined.https://authors.library.caltech.edu/records/5b3ga-mq107Structural Identification Using Linear Models and Earthquake Records
https://resolver.caltech.edu/CaltechAUTHORS:20120830-160720494
Authors: {'items': [{'id': 'Beck-J-L', 'name': {'family': 'Beck', 'given': 'James L.'}}, {'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 1980
DOI: 10.1002/eqe.4290080205
The problem of determining linear models of structures from seismic response data is investigated using ideas from the theory of system identification. The approach is to determine the optimal estimates of the model parameters by minimizing a selected measure-of-fit between the responses of the structure and the model. Because earthquake records are normally available from only a small number of locations in a structure, and because of noise in the records, it is necessary in practice to estimate parameters of the dominant modes in the records, rather than the stiffness and damping matrices of the linear model. A new algorithm is developed to determine the optimal estimates of the modal parameters. After tests with simulated data, the method is applied to a multi-storey building using records from the 1971 San Fernando earthquake in California. New information is obtained concerning the properties of the lower modes of the building and the time-varying character of the equivalent linear parameters.https://authors.library.caltech.edu/records/53e6d-65x75Memorial - Fritz Matthiesen (1926-1981)
https://resolver.caltech.edu/CaltechAUTHORS:20140903-105452668
Authors: {'items': [{'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 1982
R. B. "Fritz" Matthiesen died on 26 October 1981, at the age of 54, a victim of
cancer, and his untimely death was a sad loss to his colleagues in earthquake
engineering and seismology. We all miss his technical abilities, his sharp wit, and his
irreverent ways of dealing with bureaucracy. Fritz had long been active in the affairs
of the Seismological Society of America and was on the Board of Directors at the
time of his death. His special technical interests were in the measurement and
interpretation of strong ground motion and in the full-scale testing of structures
such as buildings, dams, and nuclear reactors, and he was one of the world leaders
in these fields. Until recently, he was Chief of the Seismic Engineering Branch of
the U.S. Geological Survey, where he worked the past eight years of his career.https://authors.library.caltech.edu/records/ptx7j-21f66Effect of distance on local magnitudes found from strong-motion records
https://resolver.caltech.edu/CaltechAUTHORS:20140814-091803141
Authors: {'items': [{'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}, {'id': 'Kanamori-H', 'name': {'family': 'Kanamori', 'given': 'Hiroo'}, 'orcid': '0000-0001-8219-9428'}]}
Year: 1983
Values of local magnitude M_L, are calculated from 56 strong-motion accelerograms recorded in the Imperial Valley earthquake of 15 October 1979 according to procedures developed earlier (Kanamori and Jennings, 1978). These data, plus similar data from the San Fernando earthquake of 9 February 1971 and additional, less numerous data from several other California earthquakes, are used to investigate the use of different measures of distance in near-field determinations of M_L: this investigation has relevance for similar uses of distances in determining seismic design criteria. In addition, the consistency of the values of M_L found from the strong-motion data is examined from the viewpoint of assessing the need for any correction in the standard attenuation curve, −log_(10)A_0(Δ).
It was found that the most consistent values of M_L result when distance is measured to the closest point on the surface trace of the fault if a site lies within a circle with diameter equal to the extent of faulting and centered on the center of faulting (center of energy release). Outside this circle, the distance measured to the center of the circle is recommended.
A consistent trend in the values of M_L found from strong-motion records is seen in the data. The values start, at zero distance, at essentially the far-field value and then decrease to −1/4 unit at about 20 km. Then they rise to +1/4 unit at 50 to 60 km. A smooth revision to the standard attenuation curve is presented which removes this systematic trend.https://authors.library.caltech.edu/records/6yepb-zw083Upthrow of objects due to horizontal impulse excitation
https://resolver.caltech.edu/CaltechAUTHORS:20140813-084600021
Authors: {'items': [{'id': 'Psycharis-I-N', 'name': {'family': 'Psycharis', 'given': 'Ioannis N.'}}, {'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 1985
The phenomenon of upthrow of rigid blocks, excited into motion by horizontal impulses, is examined in this study. A simple foundation model is used, consisting of two sets of springs and dashpots; one set near each corner of the block. Each set consists of vertical and horizontal elements. The vertical springs are not permitted to take tensile forces, so separation of the block from the ground is allowed. The associated horizontal spring separates along with the vertical spring. The response can be separated into three regimes, namely, full contact, partial uplift, and complete separation. Analytical expressions for the response are given for the first two cases; the third case is simply rigid body motion. The overall response is nonlinear and analytical criteria for upthrow were not found. The minimum value of the impulse required for complete separation, expressed as a normalized initial velocity, was determined numerically and a parametric investigation performed. Although the irregularity of the results does not allow many general conclusions to be drawn, it was found that for short blocks, a decrease in the stiffness of the horizontal foundation springs required larger impulses for separation. These effects had mixed results for tall blocks.https://authors.library.caltech.edu/records/8t651-q2369Spatial variation of ground motion determined from accelerograms recorded on a highway bridge
https://resolver.caltech.edu/CaltechAUTHORS:20140903-112427480
Authors: {'items': [{'id': 'Wilson-J-C', 'name': {'family': 'Wilson', 'given': 'John C.'}}, {'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 1985
A set of time-synchronized strong-motion accelerograms, obtained on the San Juan Bautista 156/101 Separation Bridge in California during the 6 August 1979 Coyote Lake earthquake (M_L = 5.9), are used to study the spatial variation of ground motion at the bridge site, including traveling wave effects and the influence of multiple-support excitation. Analysis of the ground motion recorded at the base of two of the bridge supports (32.6 m apart) revealed the presence of a differential support excitation having a period of ≈ 3 sec, much longer than any structural periods of the bridge. This signal also appeared as a noticeable long-period component in the superstructure displacements. Analysis of the vertical and radial components of the 3-sec ground motion indicated that ground displacements were retrograde for the duration of strong shaking, with several cycles exhibiting elliptical particle motions. These findings suggest that long-period differential support motions were induced by phase delays in a Rayleigh wave traveling across the bridge site. Further support to this premise is given by the location of the bridge site near a maxima of the Rayleigh wave radiation pattern for the Coyote Lake earthquake (based on published focal mechanism data). Traveling wave effects were also detected for compressional body waves by a correlation analysis which indicated a time delay of ≈ 7 msec between P-wave arrivals at two of the bridge supports.https://authors.library.caltech.edu/records/8bkhc-faa92Estimation of strong ground motions in Mexico City expected for large earthquakes in the Guerrero seismic gap
https://resolver.caltech.edu/CaltechAUTHORS:20140806-101251130
Authors: {'items': [{'id': 'Kanamori-H', 'name': {'family': 'Kanamori', 'given': 'Hiroo'}, 'orcid': '0000-0001-8219-9428'}, {'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}, {'id': 'Singh-Shri-Krishna', 'name': {'family': 'Singh', 'given': 'Shri Krishna'}}, {'id': 'Astiz-Luciana', 'name': {'family': 'Astiz', 'given': 'Luciana'}}]}
Year: 1993
We performed simulations of ground motions in Mexico City expected for large earthquakes in the Guerrero seismic gap in Mexico. The simulation method uses as empirical Green's functions the accelerograms recorded in Mexico City during four small to moderate earthquakes (8 Feb. 1988, M_s = 5.8; 25 April 1989, M_w = 6.9; 11 May 1990, M_w = 5.5; and 31 May 1990, M_w = 6.0) in the Guerrero gap. Because these events occurred in the Guerrero gap, and have typical thrust mechanisms, the propagation path and site effects can be accurately included in our simulation. Fault rupture patterns derived from the 1985 Michoacan earthquake and source scaling relations appropriate for Mexican subduction zone earthquakes are used. If the Guerrero event is similar to the 1985 Michoacan event, the resulting response spectrum in Mexico City will be approximately twice as large as that of the 1985 Michoacan earthquake at periods longer than 2 sec. At periods shorter than 2 sec, the amplitude will be 2 to 3 times larger than that for the Michoacan earthquake. If the events in the Guerrero seismic gap occur as a sequence of magnitude 7.5 to 7.8 events, as they did in the previous sequence around the turn of the century, the strong motion in Mexico City is estimated to be about half that experienced during the 1985 Michoacan earthquake at periods longer than 2 sec. However, several factors affect this estimate. The magnitude of the possible events has a significant range and, if a rupture sequence is such that it enhances ground-motion amplitude with constructive interference, as occurred during the second half of the Michoacan sequence, some components of the ground motion could be amplified by a factor of 2 to 3. To aid in the interpretation of the simulated motion for purposes of design or hazard assessment, design spectra for the CDAO site in Mexico City are derived from the response spectra of the simulated ground motions.https://authors.library.caltech.edu/records/gvg7j-5ky51Enduring Lessons and Opportunities Lost from the San Fernando Earthquake of February 9, 1971
https://resolver.caltech.edu/CaltechAUTHORS:JENes97
Authors: {'items': [{'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 1997
DOI: 10.1193/1.1585930
Twenty-five years have passed since the San Fernando earthquake of February 9, 1971. The paper reviews the lessons learned and not learned from this notable event. Most of the major lessons were reported within a few weeks of the earthquake by a panel appointed by the National Academies of Sciences and of Engineering. In this paper, the status of each of the eighteen general lessons cited by the panel is reviewed, plus two additional lessons selected from other studies of the earthquake. The lessons learned ranged broadly and concerned measures needed to reduce future earthquake hazards, as well as recommended scientific and engineering efforts. Although all of the lessons learned were not heeded, the San Fernando earthquake represented a turning point in public awareness and in actions taken to reduce earthquake hazard. Recent earthquakes have shown, however, that much remains to be done.https://authors.library.caltech.edu/records/qbs58-hsx63George W. Housner (1910–2008)
https://resolver.caltech.edu/CaltechAUTHORS:20090416-094551276
Authors: {'items': [{'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 2009
DOI: 10.1785/gssrl.80.2.192
George W. Housner, Carl F Braun Professor of Engineering, emeritus, died after a short illness on 10 November 2008, just a few weeks before his 98th birthday. He was in the retirement home in Pasadena where he had lived for several years. For all of us who knew George, this marked the end of an era. Few people have guided and nurtured a field the way George led earthquake engineering over a period of several decades. He had a profound effect on many people and will long be remembered. His impact was so pervasive that he earned the title "Father of Earthquake Engineering." This article records some of my thoughts about this remarkable man.https://authors.library.caltech.edu/records/p6ds7-gf472George Housner: A Personal Remembrance (1910–2008)
https://resolver.caltech.edu/CaltechAUTHORS:20110510-103230564
Authors: {'items': [{'id': 'Jennings-P-C', 'name': {'family': 'Jennings', 'given': 'Paul C.'}}]}
Year: 2009
DOI: 10.1002/eqe.906
George W. Housner, C F Braun Professor of Engineering, Emeritus, died after a short illness on
November 10, 2008, just a few weeks before his 98th birthday. He was in the retirement home
in Pasadena where he had lived for several years. For all of us who knew George, this marked
the end of an era. Few people have guided and nurtured a field the way George led earthquake
engineering over a period of several decades. He had a profound effect on many people and will
long be remembered. His impact was so pervasive that he had earned the title of the 'Father of
Earthquake Engineering'. This article records some of my thoughts about this remarkable man.https://authors.library.caltech.edu/records/q1rwb-75b24