The Experts below are selected from a list of 1419 Experts worldwide ranked by ideXlab platform
Anil K Chopra - One of the best experts on this subject based on the ideXlab platform.
-
I 997b). "Period formulas for moment resisting frame buildings
2016Co-Authors: K. Goel, Anil K ChopraAbstract:ABSTRACT: Most seismic codes specify empirical fonnulas to estimate the fundamental vibration period of buildings. Evaluated first in this paper are the fonnulas specified in present U.S. codes using the available data on the fundamental period of buildings "measured " from their motions recorded during eight California earth quakes, starting with the 1971 San Fernando Earthquake and ending with the 1994 Northridge Earthquake. It is shown that, although the code fonnulas provide periods that are generally shorter than measured periods, these fonnulas can be improved to provide better correlation with the measured data. Subsequently, improved fonnulas for estimating the fundamental periods of reinforced concrete (RC) and steel moment-resisting frame buildings are developed by regression analysis of the measured period data. Also recommended are factors to limit the period calculated by a rational analysis, such as Rayleigh's method
-
period formulas for concrete shear wall buildings
Journal of Structural Engineering-asce, 1998Co-Authors: Rakesh K Goel, Anil K ChopraAbstract:Most seismic codes specify empirical formulas to estimate the fundamental vibration period of buildings. Evaluated first in this paper are the formulas specified in present U.S. codes using the available data on the fundamental period of buildings “measured” from their motions recorded during eight California Earthquakes, starting with the 1971 San Fernando Earthquake and ending with the 1994 Northridge Earthquake. It is shown that current code formulas for estimating the fundamental period of concrete shear wall buildings are grossly inadequate. Subsequently, an improved formula is developed by calibrating a theoretical formula, derived using Dunkerley's method, against the measured period data through regression analysis. Also recommended is a factor to limit the period calculated by a “rational” analysis, such as Rayleigh's method.
-
Period Formulas for Concrete Shear Wall Buildings
1998Co-Authors: K. Goel, Anil K ChopraAbstract:ABSTRACT: Most seismic codes specify empirical fonnulas to estimate the fundamental vibration period of buildings. Evaluated first in this paper are the fonnulas specified in present U.S. codes using the available data on the fundamental period of buildings "measured " from their motions recorded during eight California e~ quakes, starting with the 1971 San Fernando Earthquake and ending w.ith the 1994 Northridge earth~u~e. It 1S shown that current code fonnulas for estimating the fundamental penod of concrete shear wall bUi1dmgs are grossly inadequate. Subsequently, an improved fonnula is developed by calibr~ting a the.oretical fonnula, deriv~ using Dunkerley's method, against the measured period data through regress10n analys1s. A]so recommended IS a factor to limit the period calculated by a "rational " analysis. such as Rayleigh's method
Benthien, Mark L. - One of the best experts on this subject based on the ideXlab platform.
-
Fault systems of the 1971 San Fernando and 1994 Northridge Earthquakes, southern California: Relocated aftershocks and seismic images from LARSE II
'Geological Society of America', 2003Co-Authors: Fuis, Gary S., Clayton, Robert W., Davis, Paul M., Ryberg Trond, Lutter, William J., Okaya, David A., Hauksson Egill, Prodehl Claus, Murphy, Janice M., Benthien, Mark L.Abstract:We have constructed a composite image of the fault systems of the M 6.7 San Fernando (1971) and Northridge (1994), California, Earthquakes, using industry reflection and oil test well data in the upper few kilometers of the crust, relocated aftershocks in the seismogenic crust, and LARSE II (Los Angeles Region Seismic Experiment, Phase II) reflection data in the middle and lower crust. In this image, the San Fernando fault system appears to consist of a decollement that extends 50 km northward at a dip of ∼25° from near the surface at the Northridge Hills fault, in the northern San Fernando Valley, to the San Andreas fault in the middle to lower crust. It follows a prominent aseismic reflective zone below and northward of the main-shock hypocenter. Interpreted upward splays off this decollement include the Mission Hills and San Gabriel faults and the two main rupture planes of the San Fernando Earthquake, which appear to divide the hanging wall into shingle- or wedge-like blocks. In contrast, the fault system for the Northridge Earthquake appears simple, at least east of the LARSE II transect, consisting of a fault that extends 20 km southward at a dip of ∼33° from ∼7 km depth beneath the Santa SuSana Mountains, where it abuts the interpreted San Fernando decollement, to ∼20 km depth beneath the Santa Monica Mountains. It follows a weak aseismic reflective zone below and southward of the main-shock hypocenter. The middle crustal reflective zone along the interpreted San Fernando decollement appears similar to a reflective zone imaged beneath the San Gabriel Mountains along the LARSE I transect, to the east, in that it appears to connect major reverse or thrust faults in the Los Angeles region to the San Andreas fault. However, it differs in having a moderate versus a gentle dip and in containing no mid-crustal bright reflections
Le Val Lund - One of the best experts on this subject based on the ideXlab platform.
-
Northridge, California, Earthquake
2016Co-Authors: Le Val LundAbstract:Abstract Lifelines performed an important role in emergency response and re-storing the community after the 17 January 1994 Northridge arthquake. Telecom-munications, radio, and electronic media played a valuable rote in directing emer-gency response for essential services, directing the repairing of damaged lifelines and informing the public of vital information. Water supply was necessary where available for public fire protection. Highways and roads were used to move rescue, repair, fire, and medical teams and their supplies and equipment to the damaged areas. Although the Northridge arthquake was severe, the lifeline disruption rep-resented a relatively small percentage of inconvenience to the total population served within the total Earthquake impact area. The 1994 Northridge vent showed improve-ment in the seismic performance of lifeline facilities and equipment installed and built, under modern seismic codes, since the 1971 San Fernando Earthquake
-
lifeline utilities performance in the 17 january 1994 northridge california Earthquake
Bulletin of the Seismological Society of America, 1996Co-Authors: Le Val LundAbstract:Abstract Lifelines performed an important role in emergency response and restoring the community after the 17 January 1994 Northridge Earthquake. Telecommunications, radio, and electronic media played a valuable role in directing emergency response for essential services, directing the repairing of damaged lifelines and informing the public of vital information. Water supply was necessary where available for public fire protection. Highways and roads were used to move rescue, repair, fire, and medical teams and their supplies and equipment to the damaged areas. Although the Northridge Earthquake was severe, the lifeline disruption represented a relatively small percentage of inconvenience to the total population served within the total Earthquake impact area. The 1994 Northridge event showed improvement in the seismic performance of lifeline facilities and equipment installed and built, under modern seismic codes, since the 1971 San Fernando Earthquake.
Fuis, Gary S. - One of the best experts on this subject based on the ideXlab platform.
-
Fault systems of the 1971 San Fernando and 1994 Northridge Earthquakes, southern California: Relocated aftershocks and seismic images from LARSE II
'Geological Society of America', 2003Co-Authors: Fuis, Gary S., Clayton, Robert W., Davis, Paul M., Ryberg Trond, Lutter, William J., Okaya, David A., Hauksson Egill, Prodehl Claus, Murphy, Janice M., Benthien, Mark L.Abstract:We have constructed a composite image of the fault systems of the M 6.7 San Fernando (1971) and Northridge (1994), California, Earthquakes, using industry reflection and oil test well data in the upper few kilometers of the crust, relocated aftershocks in the seismogenic crust, and LARSE II (Los Angeles Region Seismic Experiment, Phase II) reflection data in the middle and lower crust. In this image, the San Fernando fault system appears to consist of a decollement that extends 50 km northward at a dip of ∼25° from near the surface at the Northridge Hills fault, in the northern San Fernando Valley, to the San Andreas fault in the middle to lower crust. It follows a prominent aseismic reflective zone below and northward of the main-shock hypocenter. Interpreted upward splays off this decollement include the Mission Hills and San Gabriel faults and the two main rupture planes of the San Fernando Earthquake, which appear to divide the hanging wall into shingle- or wedge-like blocks. In contrast, the fault system for the Northridge Earthquake appears simple, at least east of the LARSE II transect, consisting of a fault that extends 20 km southward at a dip of ∼33° from ∼7 km depth beneath the Santa SuSana Mountains, where it abuts the interpreted San Fernando decollement, to ∼20 km depth beneath the Santa Monica Mountains. It follows a weak aseismic reflective zone below and southward of the main-shock hypocenter. The middle crustal reflective zone along the interpreted San Fernando decollement appears similar to a reflective zone imaged beneath the San Gabriel Mountains along the LARSE I transect, to the east, in that it appears to connect major reverse or thrust faults in the Los Angeles region to the San Andreas fault. However, it differs in having a moderate versus a gentle dip and in containing no mid-crustal bright reflections
Rakesh K Goel - One of the best experts on this subject based on the ideXlab platform.
-
period formulas for concrete shear wall buildings
Journal of Structural Engineering-asce, 1998Co-Authors: Rakesh K Goel, Anil K ChopraAbstract:Most seismic codes specify empirical formulas to estimate the fundamental vibration period of buildings. Evaluated first in this paper are the formulas specified in present U.S. codes using the available data on the fundamental period of buildings “measured” from their motions recorded during eight California Earthquakes, starting with the 1971 San Fernando Earthquake and ending with the 1994 Northridge Earthquake. It is shown that current code formulas for estimating the fundamental period of concrete shear wall buildings are grossly inadequate. Subsequently, an improved formula is developed by calibrating a theoretical formula, derived using Dunkerley's method, against the measured period data through regression analysis. Also recommended is a factor to limit the period calculated by a “rational” analysis, such as Rayleigh's method.
