Article records
https://feeds.library.caltech.edu/people/Hall-J-F/article.rss
A Caltech Library Repository Feedhttp://www.rssboard.org/rss-specificationpython-feedgenenTue, 16 Apr 2024 13:40:30 +0000Structural Damage in Mexico City
https://resolver.caltech.edu/CaltechAUTHORS:20120830-155816195
Authors: {'items': [{'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}, {'id': 'Beck-J-L', 'name': {'family': 'Beck', 'given': 'James L.'}}]}
Year: 1986
DOI: 10.1029/GL013i006p00589.
This paper describes the structural damage in Mexico City caused by the September 19, 1985 earthquake. Photographs which illustrate various features of structural behavior are included. One explanation is presented as to why buildings with fundamental periods of elastic vibration considerably below the predominant two‐second period of the ground motion were most vulnerable to damage.https://authors.library.caltech.edu/records/w3tde-jb050Factors Contributing to the Catastrophe in Mexico City During the Earthquake of September 19, 1985
https://resolver.caltech.edu/CaltechAUTHORS:20120830-155433286
Authors: {'items': [{'id': 'Beck-J-L', 'name': {'family': 'Beck', 'given': 'James L.'}}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 1986
DOI: 10.1029/GL013i006p00593
The extensive damage to high‐rise buildings in Mexico City during the September 19, 1985 earthquake is primarily due to the intensity of the ground shaking exceeding what was previously considered credible for the city by Mexican engineers. There were two major factors contributing to the catastrophe, resonance in the sediments of an ancient lake that once existed in the Valley of Mexico, and the long duration of shaking compared with other coastal earthquakes in the last 50 years. Both of these factors would be operative again if the Guerrero seismic gap ruptured in a single earthquake.https://authors.library.caltech.edu/records/bg21b-1fs19The dynamic and earthquake behaviour of concrete dams: review of experimental behaviour and observational evidence
https://resolver.caltech.edu/CaltechAUTHORS:20180522-142427900
Authors: {'items': [{'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 1988
DOI: 10.1016/S0267-7261(88)80001-0
Knowledge of the dynamic and earthquake behaviour of concrete dams comes from four sources: observations made from actual earthquakes including recorded histories of the dam response, experiments conducted on prototype dams for the purpose of determining their dynamic properties, experiments conducted on model dams including shaking table tests, and analytical investigations. The first three sources are extensively reviewed in this paper, while analytical investigations are included only if they were conducted to establish correlation to earthquake observations or experimental results. The subject of nonlinear constitutive modelling of concrete and foundation materials, together with its large body of experimental data, is omitted. While the review of the indicated subjects is by no means complete, it represents a much greater effort than has previously been attempted. Significant gaps occur with the non-English literature, including Japanese, Chinese and Russian, and with the work performed at ISMES in Italy and LNEC in Portugal which has not appeared to much extent in the earthquake engineering literature. A summary with recommendations for future work follows the review.https://authors.library.caltech.edu/records/ejzd9-mjs90Centrifuge Study of Faulting Effects on Tunnel
https://resolver.caltech.edu/CaltechAUTHORS:20141104-105321976
Authors: {'items': [{'id': 'Burridge-P-B', 'name': {'family': 'Burridge', 'given': 'Paul Brian'}}, {'id': 'Scott-R-F', 'name': {'family': 'Scott', 'given': 'Ronald F.'}}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 1989
DOI: 10.1061/(ASCE)0733-9410(1989)115:7(949)
If a tunnel crosses a geological fault which is considered to be active, the possibility of a displacement in the fault must be accounted for in the tunnel design. When the tunnel is embedded in soil, the assessment of the effect of the fault movement is not easy to assess. As a guide to analysis, a series of correctly scaled model experiments in a centrifuge is undertaken. The deflections and stresses induced in a tunnel crossing a fault caused by: (a) Fault displacement; and (b) differential earthquake motions across the fault are quantified by a series of centrifuge tests on a finite length model tunnel. The centrifuge results are used to calibrate a one‐dimensional finite element model of the tunnel for soil‐tunnel interaction effects. The numerical model is then used to predict the response of an essentially infinite length tunnel for design purposes. Bending movements, displacements and shears are displayed. Surprisingly small changes in the bending movements from the finite‐length to the infinite tunnel case are obtained.https://authors.library.caltech.edu/records/kw2y0-q3e62Shaking table study of concrete gravity dam monoliths
https://resolver.caltech.edu/CaltechAUTHORS:20180330-135229464
Authors: {'items': [{'id': 'Donlon-W-P', 'name': {'family': 'Donlon', 'given': 'William P.'}}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 1991
DOI: 10.1002/eqe.4290200805
A series of shaking table tests was performed on three small‐scale models of a monolith of a concrete gravity dam in order to simulate earthquake shaking. The purpose of the tests was to examine the nature of crack formation in a gravity dam and the stability of the dam in the presence of cracks. No failures occurred even though the levels of shaking employed were unrealistically high. The good performance owed to the development of crack profiles which had favourable orientations to resist sliding failures in each case. However, the development of an unfavourable crack profile, which cannot be ruled out, and the possibility of water intrusion into open cracks, something not included in the experiments, could lead to failure under significantly lower levels of excitation than those employed.https://authors.library.caltech.edu/records/gsdwa-mwg49Linear System Response by DFT: Analysis of a Recent Modified Method
https://resolver.caltech.edu/CaltechAUTHORS:20120830-153213661
Authors: {'items': [{'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}, {'id': 'Beck-J-L', 'name': {'family': 'Beck', 'given': 'James L.'}}]}
Year: 1993
DOI: 10.1002/eqe.4290220705
An analysis of a recent modified frequency-domain procedure for computing the response of linear systems using the fast Fourier transform (FFT) algorithm is described. This modified procedure eliminates the appended free-vibration interval that is used in the standard approach. The duration of the period of computation still needs to be longer than that of the response interval of interest, but only slightly. Reducing the period of computation lowers the number of frequencies at which the transfer function needs to be defined. The major drawback of the method is a high sensitivity to errors in the computed values of the transfer function, which reduces the role of interpolation in the transfer function definition. The modified method is related to the discrete Laplace transform.https://authors.library.caltech.edu/records/t29zg-0yg33Direct Boundary Element Method for Dynamics in a Half-Space
https://resolver.caltech.edu/CaltechAUTHORS:20140806-091621728
Authors: {'items': [{'id': 'Nowak-Paul-Scott', 'name': {'family': 'Nowak', 'given': 'Paul S.'}}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 1993
An application of the direct boundary element method for solving the response of a linearly elastic half-space with a canyon cut into the surface is presented. This approach uses source solutions for an undamped half-space where the resulting singular integral equations are solved directly without adding any artificial damping. Solutions for the displacements on the canyon surface reveal an artificial resonance phenomenon when solving the exterior problem in the frequency domain. The use of an additional source loading in the boundary element method is shown to eliminate these resonances and yield accurate results. A method for solving the Rayleigh waves generated on the surface of the half-space caused by the canyon is shown.https://authors.library.caltech.edu/records/hayam-2yb34The Magnitude 6.7 Northridge, California, Earthquake of 17 January 1994
https://resolver.caltech.edu/CaltechAUTHORS:20121120-075947813
Authors: {'items': [{'id': 'Jones-L-M', 'name': {'family': 'Jones', 'given': 'L.'}, 'orcid': '0000-0002-2690-3051'}, {'id': 'Aki-Keiiti', 'name': {'family': 'Aki', 'given': 'K.'}}, {'id': 'Boore-D', 'name': {'family': 'Boore', 'given': 'D.'}}, {'id': 'Celebi-M', 'name': {'family': 'Celebi', 'given': 'M.'}}, {'id': 'Donnellan-A', 'name': {'family': 'Donnellan', 'given': 'A.'}}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'J.'}, 'orcid': '0000-0002-7863-5060'}, {'id': 'Harris-R', 'name': {'family': 'Harris', 'given': 'R.'}}, {'id': 'Hauksson-E', 'name': {'family': 'Hauksson', 'given': 'E.'}, 'orcid': '0000-0002-6834-5051'}, {'id': 'Heaton-T-H', 'name': {'family': 'Heaton', 'given': 'T.'}, 'orcid': '0000-0003-3363-2197'}, {'id': 'Hough-S-E', 'name': {'family': 'Hough', 'given': 'S.'}, 'orcid': '0000-0002-5980-2986'}, {'id': 'Hudnut-K-W', 'name': {'family': 'Hudnut', 'given': 'K.'}, 'orcid': '0000-0002-3168-4797'}, {'id': 'Hutton-K', 'name': {'family': 'Hutton', 'given': 'K.'}}, {'id': 'Johnston-M-L', 'name': {'family': 'Johnston', 'given': 'M.'}}, {'id': 'Joyner-W', 'name': {'family': 'Joyner', 'given': 'W.'}}, {'id': 'Kanamori-H', 'name': {'family': 'Kanamori', 'given': 'H.'}, 'orcid': '0000-0001-8219-9428'}, {'id': 'Marshall-G', 'name': {'family': 'Marshall', 'given': 'G.'}}, {'id': 'Michael-A', 'name': {'family': 'Michael', 'given': 'A.'}}, {'id': 'Mori-Jim', 'name': {'family': 'Mori', 'given': 'J.'}}, {'id': 'Murray-M', 'name': {'family': 'Murray', 'given': 'M.'}}, {'id': 'Ponti-D', 'name': {'family': 'Ponti', 'given': 'D.'}, 'orcid': '0000-0002-2437-5144'}, {'id': 'Reasenberg-P', 'name': {'family': 'Reasenberg', 'given': 'P.'}}, {'id': 'Schwartz-D', 'name': {'family': 'Schwartz', 'given': 'D.'}}, {'id': 'Seeber-L', 'name': {'family': 'Seeber', 'given': 'L.'}}, {'id': 'Shakal-A-K', 'name': {'family': 'Shakal', 'given': 'A.'}}, {'id': 'Simpson-R', 'name': {'family': 'Simpson', 'given': 'R.'}}, {'id': 'Thio-H', 'name': {'family': 'Thio', 'given': 'H.'}}, {'id': 'Tinsley-J', 'name': {'family': 'Tinsley', 'given': 'J.'}}, {'id': 'Todorovska-M', 'name': {'family': 'Todorovska', 'given': 'M.'}}, {'id': 'Trifunac-M-D', 'name': {'family': 'Trifunac', 'given': 'M.'}}, {'id': 'Wald-D', 'name': {'family': 'Wald', 'given': 'D.'}}, {'id': 'Zoback-M-L', 'name': {'family': 'Zoback', 'given': 'M. L.'}}]}
Year: 1994
DOI: 10.1126/science.266.5184.389
The most costly American earthquake since 1906 struck Los Angeles on 17 January 1994. The magnitude 6.7 Northridge earthquake
resulted from more than 3 meters of reverse slip on a 1 5-kilometer-long south-dipping thrust fault that raised the Santa Susana mountains
by as much as 70 centimeters. The fault appears to be truncated by the fault that broke in the 1971 San Fernando earthquake at a depth
of 8 kilometers. Of these two events, the Northridge earthquake caused many times more damage, primarily because its causative fault
is directly under the city. Many types of structures were damaged, but the fracture of welds in steel-frame buildings was the greatest
surprise. The Northridge earthquake emphasizes the hazard posed to Los Angeles by concealed thrust faults and the potential for strong
ground shaking in moderate earthquakes.https://authors.library.caltech.edu/records/579x8-mcc53Response of High-Rise and Base-isolated Buildings to a Hypothetical M_w 7.0 Blind Thrust Earthquake
https://resolver.caltech.edu/CaltechAUTHORS:20130220-113228201
Authors: {'items': [{'id': 'Heaton-T-H', 'name': {'family': 'Heaton', 'given': 'Thomas H.'}, 'orcid': '0000-0003-3363-2197'}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}, {'id': 'Wald-D-J', 'name': {'family': 'Wald', 'given': 'David J.'}}, {'id': 'Halling-M-W', 'name': {'family': 'Halling', 'given': 'Marvin W.'}}]}
Year: 1995
DOI: 10.1126/science.267.5195.206
High-rise flexible-frame buildings are commonly considered to be resistant to shaking from the largest earthquakes. In addition, base isolation has become increasingly popular
for critical buildings that should still function after an earthquake. How will these two types of buildings perform if a large earthquake occurs beneath a metropolitan area? To answer this question, we simulated the near-source ground motions of a M_w 7.0 thrust earthquake and then mathematically modeled the response of a 20-story steel-frame building and a 3-story base-isolated building. The synthesized ground motions were characterized by
large displacement pulses (up to 2 meters) and large ground velocities. These ground motions caused large deformation and possible collapse of the frame building, and they
required exceptional measures in the design of the base-isolated building if it was to remain functional.https://authors.library.caltech.edu/records/w5d1k-1ke70Near-Source Ground Motion and its Effects on Flexible Buildings
https://resolver.caltech.edu/CaltechAUTHORS:HALes95
Authors: {'items': [{'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}, {'id': 'Heaton-T-H', 'name': {'family': 'Heaton', 'given': 'Thomas H.'}, 'orcid': '0000-0003-3363-2197'}, {'id': 'Halling-M-W', 'name': {'family': 'Halling', 'given': 'Marvin W.'}}, {'id': 'Wald-D-J', 'name': {'family': 'Wald', 'given': 'David J.'}}]}
Year: 1995
DOI: 10.1193/1.1585828
Occurrence of large earthquakes close to cities in California is inevitable. The resulting ground shaking will subject buildings in the near-source region to large, rapid displacement pulses which are not represented in design codes. The simulated Mw7.0 earthquake on a blind-thrust fault used in this study produces peak ground displacement and velocity of 200 cm and 180 cm/sec, respectively. Over an area of several hundred square kilometers in the near-source region, flexible frame and base-isolated buildings would experience severe nonlinear behavior including the possibility of collapse at some locations. The susceptibility of welded connections to fracture significantly increases the collapse potential of steel-frame buildings under strong ground motions of the type resulting from the Mw7.0 simulation. Because collapse of a building depends on many factors which are poorly understood, the results presented here regarding collapse should be interpreted carefully.https://authors.library.caltech.edu/records/4bbmv-31014Seismic response of steel frame buildings to near-source ground motions
https://resolver.caltech.edu/CaltechAUTHORS:20180418-153910412
Authors: {'items': [{'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 1998
DOI: 10.1002/(SICI)1096-9845(199812)27:12%3C1445::AID-EQE794%3E3.0.CO;2-C
Simulated ground motions from the M_W 6·7 Northridge earthquake and a simulated M_W 7·0 Elysian Park event are generated over a large grid of sites and used as input to mathematical models of six‐storey and 20‐storey steel‐frame buildings. Purpose of the study is to quantify effects of strong near‐source ground motion on frame buildings of different height and strength (UBC vs. Japanese design) and with welded connections prone to fracture. Best performance is achieved by the six‐storey building which meets the stronger Japanese design provisions. The detrimental effect of connection fracture is significant, especially for the larger earthquake.https://authors.library.caltech.edu/records/91d4p-dw770Isolated Buildings and the 1997 UBC Near-Source Factors
https://resolver.caltech.edu/CaltechAUTHORS:HALes00
Authors: {'items': [{'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}, {'id': 'Ryan-K-L', 'name': {'family': 'Ryan', 'given': 'Keri L.'}}]}
Year: 2000
DOI: 10.1193/1.1586118
Computer simulations are employed to assess the effects of near-source ground motions on base-isolated buildings that meet the provisions of the 1997 Uniform Building Code. A six-story base-isolated building designed for Nv = 1.6 exhibits essentially elastic structural behavior when subjected to six actual ground motions containing strong near-source effects. However, two simulated records, one intended to represent the most severe motions from the 1994 Northridge earthquake and the other a strong motion from a hypothetical Mw7.0 thrust earthquake produce larger responses well into the nonlinear range. In addition, a 113 cm ground displacement pulse of three-second duration, which is close to the period of the isolated buildings, causes story drifts of nearly 5% for the Nv = 1.6 design and over 2% for a stronger Nv = 2 design. Such drifts are effectively reduced when supplemental dampers are added alongside the isolators. The original Nv = 1.6 design with supplemental damping in the amount of 20% of critical experiences only 1.3% drift for the same three-second ground displacement pulse.https://authors.library.caltech.edu/records/apzer-jbg19Characterization of near-source ground motions with earthquake simulations
https://resolver.caltech.edu/CaltechAUTHORS:AAGes01
Authors: {'items': [{'id': 'Aagaard-B-T', 'name': {'family': 'Aagaard', 'given': 'Brad T.'}}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}, {'id': 'Heaton-T-H', 'name': {'family': 'Heaton', 'given': 'Thomas H.'}, 'orcid': '0000-0003-3363-2197'}]}
Year: 2001
DOI: 10.1193/1.1586171
We examine the characteristics of long-period near-source ground motions by conducting a sensitivity study with variations in six earthquake source parameters for both a strike-slip fault (M 7.0-7.1) and a thrust fault (M 6.6-7.0). The directivity of the ruptures creates large displacement and velocity pulses in the forward direction. The dynamic displacements close to the fault are comparable to the average slip. The ground motions exhibit the greatest sensitivity to the fault depth with moderate sensitivity to the rupture speed, peak slip rate, and average slip. For strike-slip faults and thrust faults with surface rupture, the maximum ground displacements and velocities occur in the region where the near-source factor from the 1997 Uniform Building Code is the largest. However, for a buried thrust fault the peak ground motions can occur up-dip from this region.https://authors.library.caltech.edu/records/x0ms8-hwx90Dynamic Earthquake Ruptures in the Presence of Lithostatic Normal Stresses: Implications for Friction Models and Heat Production
https://resolver.caltech.edu/CaltechAUTHORS:20121120-094358596
Authors: {'items': [{'id': 'Aagaard-B-T', 'name': {'family': 'Aagaard', 'given': 'Brad T.'}}, {'id': 'Heaton-T-H', 'name': {'family': 'Heaton', 'given': 'Thomas H.'}, 'orcid': '0000-0003-3363-2197'}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 2001
DOI: 10.1785/0120000257
We simulate dynamic ruptures on a strike-slip fault in homogeneous and layered half-spaces and on a thrust fault in a layered half-space. With traditional friction models, sliding friction exceeds 50% of the fault normal compressive stress, and unless the pore pressures approach the lithostatic stress, the rupture characteristics depend strongly on the depth, and sliding generates large amounts of heat. Under application of reasonable stress distributions with depth, variation of the effective coefficient of friction with the square root of the shear modulus and the inverse of the depth creates distributions of stress drop and fracture energy that produce realistic rupture behavior. This ad hoc friction model results in (1) low-sliding friction at all depths and (2) fracture energy that is relatively independent of depth. Additionally, friction models with rate-weakening behavior (which form pulselike ruptures) appear to generate heterogeneity in the distributions of final slip and shear stress more effectively than those without such behavior (which form cracklike ruptures). For surface rupture on a thrust fault, the simple slip-weakening friction model, which lacks rate-weakening behavior, accentuates the dynamic interactions between the seismic waves and the rupture and leads to excessively large ground motions on the hanging wall. Waveforms below the center of the fault (which are associated with waves radiated to teleseismic distances) indicate that source inversions of thrust events may slightly underestimate the slip at shallow depths.https://authors.library.caltech.edu/records/d3amz-qvs61Effects of Fault Dip and Slip Rake Angles on Near-Source Ground Motions: Why Rupture Directivity Was Minimal in the 1999 Chi-Chi, Taiwan, Earthquake
https://resolver.caltech.edu/CaltechAUTHORS:20121212-153925352
Authors: {'items': [{'id': 'Aagaard-B-T', 'name': {'family': 'Aagaard', 'given': 'Brad T.'}}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}, {'id': 'Heaton-T-H', 'name': {'family': 'Heaton', 'given': 'Thomas H.'}, 'orcid': '0000-0003-3363-2197'}]}
Year: 2004
DOI: 10.1785/0120030053
We study how the fault dip and slip rake angles affect near-source ground velocities and displacements as faulting transitions from strike-slip motion on a vertical fault to thrust motion on a shallow-dipping fault. Ground motions are computed for five fault geometries with different combinations of fault dip and rake angles and common values for the fault area and the average slip. The nature of the shear-wave directivity is the key factor in determining the size and distribution of the peak velocities and displacements. Strong shear-wave directivity requires that (1) the observer is located in the direction of rupture propagation and (2) the rupture propagates parallel to the direction of the fault slip vector. We show that predominantly along-strike rupture of a thrust fault (geometry similar in the Chi-Chi earthquake) minimizes the area subjected to large-amplitude velocity pulses associated with rupture directivity, because the rupture propagates perpendicular to the slip vector; that is, the rupture propagates in the direction of a node in the shear-wave radiation pattern. In our simulations with a shallow hypocenter, the maximum peak-to-peak horizontal velocities exceed 1.5 m/sec over an area of only 200 km^2 for the 30°-dipping fault (geometry similar to the Chi-Chi earthquake), whereas for the 60°- and 75°-dipping faults this velocity is exceeded over an area of 2700 km^2. These simulations indicate that the area subjected to large-amplitude long-period ground motions would be larger for events of the same size as Chi-Chi that have different styles of faulting or a deeper hypocenter.https://authors.library.caltech.edu/records/1z5zy-jam38Simulated performance of steel moment-resisting frame buildings in the 2003 Tokachi-oki earthquake
https://resolver.caltech.edu/CaltechAUTHORS:20121126-150844917
Authors: {'items': [{'id': 'Heaton-T-H', 'name': {'family': 'Heaton', 'given': 'Thomas'}, 'orcid': '0000-0003-3363-2197'}, {'id': 'Yang-Jing', 'name': {'family': 'Yang', 'given': 'Jing'}}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 2006
We simulate the response of 6 and 20 story steel moment-resisting frame buildings (US 1994 UBC) for ground motions recorded in the 2003 Tokachi-oki earthquake. We consider buildings with both perfect welds and also with brittle welds similar to those observed in the 1994 Northridge earthquake. Although existing short, strong buildings in Japanese towns performed well in this earthquake, our simulations indicate that flexible buildings would have been strongly excited by this earthquake. Simulated deformations are large enough in some basin regions that one could expect irreparable damage at many locations for both the 6- and 20-story buildings. In a few instances, the 20-story building with brittle welds experienced dangerously large deformations.https://authors.library.caltech.edu/records/q9xtw-1ne31Modeling Steel Frame Buildings in Three Dimensions. I: Panel Zone and Plastic Hinge Beam Elements
https://resolver.caltech.edu/CaltechAUTHORS:20130311-091205741
Authors: {'items': [{'id': 'Krishnan-Swaminathan', 'name': {'family': 'Krishnan', 'given': 'Swaminathan'}, 'orcid': '0000-0002-2594-1523'}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 2006
DOI: 10.1061/(ASCE)0733-9399(2006)132:4(345)
A procedure for efficient three-dimensional nonlinear time-history analysis of steel framed buildings is derived. It incorporates two types of nonlinear beam elements—the plastic hinge type and the elastofiber type—and nonlinear panel zone elements to model yielding and strain-hardening in moment-frames. Floors and roofs of buildings are modeled using 4-node elastic diaphragm elements. The procedure utilizes an iteration strategy applied to an implicit time-integration scheme to solve the nonlinear equations of motion at each time step. Geometric nonlinearity is included. An overview of the procedure and the theories for the panel zone and the plastic hinge elements are presented in this paper. The theory for the elastofiber element along with illustrative examples are presented in a companion paper. The plastic hinge beam element consists of two nodes at which biaxial flexural yielding is permitted, leading to the formation of plastic hinges. Elastic rotational springs are connected across the plastic hinge locations to model strain-hardening. Axial yielding is also permitted. The panel zone element consists of two orthogonal panels forming a cruciform section. Each panel may yield and strain-harden in shear.https://authors.library.caltech.edu/records/0z74g-f6c59Parallelized Implicit Nonlinear FEA Program for Real Scale RC Structures under Cyclic Loading
https://resolver.caltech.edu/CaltechAUTHORS:20120608-145954084
Authors: {'items': [{'id': 'Cho-In-Ho', 'name': {'family': 'Cho', 'given': 'In Ho'}}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 2012
DOI: 10.1061/(ASCE)CP.1943-5487.0000138
Parallel computing in civil engineering has been restricted to monotonic shock or blast loading with explicit algorithm which is characteristically feasible to be parallelized. In the present paper, efficient parallelization strategies for the highly demanded implicit nonlinear finite-element analysis (FEA) program for real scale reinforced concrete (RC) structures under cyclic loading are proposed. Quantitative comparison of state-of-the-art parallel strategies in terms of factorization were carried out, leading to the problem-optimized solver, which successfully embraces the penalty method and banded nature. Particularly, the penalty method employed imparts considerable smoothness to the global response, which yields practical superiority of the parallel triangular system solution over those of advanced solvers such as the parallel preconditioned conjugate gradient method. Other salient issues on parallelization are also addressed. By virtue of the parallelization, the analysis platform offers unprecedented access to physics-based mechanisms and probabilistic randomness at the entire system level and realistically reproduces global degradation and localized damage, as reflected from the application to a RC structure. Equipped with accuracy, stability and scalability, the parallel platform is believed to serve as a fertile ground for the introducing of further physical mechanisms into various research fields, as well as the earthquake engineering community.https://authors.library.caltech.edu/records/xrr1f-fby16General Confinement Model Based on Nonlocal Information
https://resolver.caltech.edu/CaltechAUTHORS:20140612-082336397
Authors: {'items': [{'id': 'Cho-In-Ho', 'name': {'family': 'Cho', 'given': 'In Ho'}}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 2014
DOI: 10.1061/(ASCE)EM.1943-7889.0000724
The confinement effect has been of significant importance for improving the resilience against extreme compression loadings such as seismic excitations. Notwithstanding the accuracy of previous confinement models, some challenges remain regarding their applicability. The previous approaches often build on structure-dependent parameters necessitating intractable calibrations, and their formulations are defined on an integration point or a small portion of the structure, thereby precluding general applicability to complicated real-scale RC structures. Here a general confinement model is proposed in a novel way that it can harness physical information inside the real-scale system. The information is denoted nonlocal information, since it is processed by the nonlocal formulation for assuring the mesh-objectivity. Physically, the nonlocal information provides the proximity to adjacent stiff materials and boundaries through the information index suggested herein. Numerical issues regarding the parallel computing and the optimal selection of the length parameter for the nonlocal formulation are also addressed. The unprecedentedly broad applications include a solid column, a hollow column, a rectangular wall, a T-shaped wall, and even a wall with opening, which strongly bear out the promising potential and universality of the novel confinement model.https://authors.library.caltech.edu/records/s2mxr-32359Characterizing Ground Motions That Collapse Steel Special Moment-Resisting Frames or Make Them Unrepairable
https://resolver.caltech.edu/CaltechAUTHORS:20150625-084904354
Authors: {'items': [{'id': 'Olsen-A-H', 'name': {'family': 'Olsen', 'given': 'Anna H.'}}, {'id': 'Heaton-T-H', 'name': {'family': 'Heaton', 'given': 'Thomas H.'}, 'orcid': '0000-0003-3363-2197'}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 2015
DOI: 10.1193/102612EQS318M
This work applies 64,765 simulated seismic ground motions to four models each of 6- or 20-story, steel special moment-resisting frame buildings. We consider two vector intensity measures and categorize the building response as "collapsed," "unrepairable," or "repairable." We then propose regression models to predict the building responses from the intensity measures. The best models for "collapse" or "unrepairable" use peak ground displacement and velocity as intensity measures, and the best models predicting peak interstory drift ratio, given that the frame model is "repairable," use spectral acceleration and epsilon (ϵ) as intensity measures. The more flexible frame is always more likely than the stiffer frame to "collapse" or be "unrepairable." A frame with fracture-prone welds is substantially more susceptible to "collapse" or "unrepairable" damage than the equivalent frame with sound welds. The 20-story frames with fracture-prone welds are more vulnerable to P-delta instability and have a much higher probability of collapse than do any of the 6-story frames.https://authors.library.caltech.edu/records/f9zc3-qq302Discussion of 'Modelling viscous damping in nonlinear response history analysis of buildings for earthquake excitation' by Anil K. Chopra and Frank McKenna
https://resolver.caltech.edu/CaltechAUTHORS:20161111-101200256
Authors: {'items': [{'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 2016
DOI: 10.1002/eqe.2761
This discussion deals with recommendations in the paper on appropriate damping formulations for use in nonlinear response history analysis of buildings. Concern over potentially excessive damping forces and moments should extend beyond the damping moments produced by the stiffness proportional part of Rayleigh damping that corresponds to rotational springs used to explicitly model plastic hinges. The key to an appropriate damping formulation for nonlinear analysis is a realistic mechanism that allows all damping forces and moments to be meaningfully assessed. Then features can be added to keep these forces and moments within reasonable bounds.https://authors.library.caltech.edu/records/0j0mj-r0181Discussion on 'an investigation into the effects of damping and nonlinear geometry models in earthquake analysis' by Andrew Hardyniec and Finley Charney
https://resolver.caltech.edu/CaltechAUTHORS:20170323-081803283
Authors: {'items': [{'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 2017
DOI: 10.1002/eqe.2786
The discussed paper explores how various assumptions for damping and geometric nonlinearity affect the seismic collapse behavior of steel-frame buildings. The recommended damping scheme is questioned, and an alternative is suggested. Additional explanation is sought to justify the differences observed between the P-delta and co-rotational models for geometric nonlinearity.https://authors.library.caltech.edu/records/anxhk-y5g63On the descending branch of the pushover curve for multistory buildings
https://resolver.caltech.edu/CaltechAUTHORS:20180215-093244268
Authors: {'items': [{'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 2018
DOI: 10.1002/eqe.2990
The paper discusses nonlinear pushover curves for multistory moment-frame buildings. Attention is brought to the steepening effect that elastic unloading has on the slope of the descending branch of the pushover curve, with the possibility of snapback. Displacement control is shown to be effective for the entire range of pushover analysis, including the descending branch. The method is enhanced by controlling the difference in displacement of 2 floors in the vicinity of the collapse mechanism rather than, say, controlling the roof displacement. An automated drift control version is described and tested. Analysis of a 20-story building demonstrates that variable strength of plastic hinges and inclusion of the strength and stiffness of the gravity frames in the model affect the pushover curve significantly, especially the descending branch. The concept of dynamic pushover is described, and results are compared with the static version.https://authors.library.caltech.edu/records/7ranq-cqw73Discussion of "A new inherent damping model for inelastic time‐history analyses" by Enrique Luco and Armando Lanzi
https://resolver.caltech.edu/CaltechAUTHORS:20180726-100724376
Authors: {'items': [{'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 2018
DOI: 10.1002/eqe.3061
This discussion examines several aspects of the proposed elastic velocity damping formulation that pertain to the suitability of the method for use in inelastic time history analysis. These aspects include the absence of damping actions as a structure moves through a collapse mechanism, lack of physical justification, and potential computational issues.https://authors.library.caltech.edu/records/sxztc-jzn29Performance of viscous damping in inelastic seismic analysis of moment-frame buildings
https://resolver.caltech.edu/CaltechAUTHORS:20181024-134613535
Authors: {'items': [{'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}]}
Year: 2018
DOI: 10.1002/eqe.3104
This paper investigates the performance of viscous damping in the inelastic seismic analysis of moment‐frame buildings using a detailed model of a 20‐story steel structure. Damping schemes included are Rayleigh, condensed Rayleigh, Wilson‐Penzien, tangent Rayleigh, elastic velocity Rayleigh, and capped damping. Caughey damping is found not to be computationally viable. Differences among the damping schemes, as quantified by plastic hinge rotations and story drifts, become noticeable once these quantities reach the 3% level. In order of least to greatest hinge rotations and story drifts that occur under lateral response to horizontal ground motion, the damping schemes rank as Rayleigh (most damping action), condensed Rayleigh, Wilson‐Penzien, tangent Rayleigh and capped damping, which are about the same, and elastic velocity Rayleigh (least damping action). Performance of Rayleigh damping under vertical ground motion is discussed, including the effect of soil‐structure interaction. The propensity of Rayleigh damping to generate excessive damping forces and moments during inelastic seismic analysis is explained, and a parameter is introduced that can predict the potential magnitude of the effect. A review of some literature on amplified Rayleigh damping moments is also presented.https://authors.library.caltech.edu/records/3vzp2-2f314Modeling the Rocking and Sliding of Free-Standing Objects Using Rigid Body Dynamics
https://resolver.caltech.edu/CaltechAUTHORS:20200514-144614293
Authors: {'items': [{'id': 'Veeraraghavan-Swetha', 'name': {'family': 'Veeraraghavan', 'given': 'Swetha'}, 'orcid': '0000-0002-8667-6022'}, {'id': 'Hall-J-F', 'name': {'family': 'Hall', 'given': 'John F.'}, 'orcid': '0000-0002-7863-5060'}, {'id': 'Krishnan-Swaminathan', 'name': {'family': 'Krishnan', 'given': 'Swaminathan'}, 'orcid': '0000-0002-2594-1523'}]}
Year: 2020
DOI: 10.1061/(asce)em.1943-7889.0001739
A rigid body dynamics algorithm is presented in this paper to simulate the interaction between two rigid bodies, a free-standing rigid object, and a pedestal that has infinite mass, in the presence of static and kinetic friction forces. Earlier algorithms led to different solutions for the contact forces when parameters external to problem description, such as the ordering of contact points, are changed. This paper addresses the issue of selecting an appropriate solution for the contact forces and impulses from the infinite set of solutions by picking the solution that is closest to the previous state of the rigid body. The capability of this algorithm in simulating pure rocking, pure sliding, and coupled rocking-sliding response modes of a rectangular block is validated using analytical/semianalytical results. This validated algorithm is later used to identify the various response modes of a rectangular block, which is given an initial tilt and then released.https://authors.library.caltech.edu/records/0sb59-t4y92