Geology topics

Moh Huang

Publications and source records attributed to Moh Huang.

4 recordsLinked to original sources

USGS2019

The behavior of the Salesforce Tower, the tallest building in San Francisco, California inferred from earthquake and ambient shaking

The newly constructed tallest building designed in conformance with performance-based design procedure in San Francisco, California is a 61-story building equipped with an accelerometric array that recorded the January 4, 2018 M4.4 Berkeley earthquake. The building is designed with concrete core shear walls and perimeter gravity steel columns. The earthquake records as well as on-demand recorded ambient responses of the building are studied to determine its dynamic characteristics and building-specific behavior. At the level of shaking of either the earthquake or ambient excitation, the frequencies and low modal damping ratios (<2%) are similar. The building exhibits torsional behavior most likely due to abrupt asymmetrical changes in the size of the core shear wall. The translational and torsional modes during the earthquake are closely coupled, which leads to a beating effect, the period of which is calculable. Due to the relatively low-amplitude shaking during the earthquake, the drift ratios were small and did not cause any damage. It is expected that during stronger shaking levels, these characteristics may change.

California↗

USGS2013

Ambient response of a unique performance-based design tall building with dynamic response modification features

A 64-story, performance-based design building with reinforced concrete core shear walls and unique dynamic response modification features (tuned liquid sloshing dampers and buckling-restrained braces) has been instrumented with a monitoring array of 72 channels of accelerometers. The responses of the building to ambient motions from ground or wind were recorded and analyzed to identify modes and associated frequencies and damping. Not unexpectedly, the low-amplitude dynamic characteristics are considerably different than those computed from design analyses. Nonetheless, these computed values serve as a baseline against which to compare future strong shaking responses. Such studies help to improve our understanding of the effectiveness of the response modification features at various levels of shaking, to evaluate the predictive capabilities of the design analysis tools and to improve similar designs in the future.

California↗

USGS2012

Ambient response of a unique performance-based design building with dynamic response modification features

A 64-story, performance-based design building with reinforced concrete core shear-walls and unique dynamic response modification features (tuned liquid sloshing dampers and buckling-restrained braces) has been instrumented with a monitoring array of 72 channels of accelerometers. Ambient vibration data recorded are analyzed to identify modes and associated frequencies and damping. The low-amplitude dynamic characteristics are considerably different than those computed from design analyses, but serve as a baseline against which to compare with future strong shaking responses. Such studies help to improve our understanding of the effectiveness of the added features to the building and help improve designs in the future.

California↗

USGS2005

Preliminary analysis of strong-motion recordings from the 28 September 2004 Parkfield, California earthquake

The 2004 M w 6.0 Parkfield earthquake of 28 September 2004 occurred on the San Andreas Fault near the small town of Parkfield in central California. As a result of a widely accepted likelihood of an earthquake in the area, a large number of strong-motion stations and other types of seismic stations had been deployed in the area. The Parkfield earthquake occurred along the same segment of the San Andreas Fault that ruptured during the 1966 Parkfield earthquake, resulting in a unique set of strong-motion measurements by arrays designed specifically for the purpose of recording an event along this fault segment. The most extensive and dense set of near-fault strong-motion recordings yet obtained for any earthquake in California was obtained in this event. This paper provides a detailed description of the arrays and the resultant strong-motion measurements of the mainshock, as well as preliminary observations. We also invite interested parties to participate in the Turkey Flat blind prediction experiment, described later in the paper. More general preliminary seismological results for this earthquake can be found in Langbein et al. ( 2005 , this issue).

California↗