The Mw 6.3 Meinong earthquake, which struck southern Taiwan on February 6, 2016, was characterize... more The Mw 6.3 Meinong earthquake, which struck southern Taiwan on February 6, 2016, was characterized by an oblique left lateral strike-slip motion with a minor reverse component. The earthquake occurred at approximately 16 km depth on an unknown fault that did not rupture the ground surface, but rather produced a noticeable long period velocity pulse east to west, with the strongest amplitude motions recorded about 30km west of the epicentral region in Tainan City. Within this city, more than 20 multi-story buildings constructed under relatively modern building codes were severely damaged, including seven that suffered complete collapse. In addition, there was widespread damage associated with liquefaction, a substantial portion of which affected residential buildings causing large uniform and differential settlement, the later causing severe tilt to buildings in many cases. In response to this event, local earthquake professionals, faculty members, and students teamed with US NSF-spo...
Strasser, F. (2007). Estimates of VS30 values for the K-Net stations based on extrapolation of th... more Strasser, F. (2007). Estimates of VS30 values for the K-Net stations based on extrapolation of the velocity profile, personal communication. TEPCO (2007). Report on analysis of observed records at Kashiwazaki-Kariwa Nuclear Power Plant during the Niigata-Chuetsu-Oki earthquake 2007.
Crane Valley Dam is located on the North Fork of Willow Creek in Madera County, California, and i... more Crane Valley Dam is located on the North Fork of Willow Creek in Madera County, California, and is owned by Pacific Gas & Electric Company (PG&E). The results of seismic stability analyses performed in 2005 and 2006 showed that the dam’s hydraulic fill embankments would experience large deformations during and after the earthquake shaking postulated for the site. To improve the seismic stability and performance of the dam, PG&E initiated the Crane Valley Dam Seismic Retrofit Project (Project), which includes placing new rockfill buttresses on the upstream and downstream slopes of the dam, constructing internal drainage improvements, reinforcing portions of the dam’s concrete core wall, and raising the dam crest. Project components were designed to meet seepage control and seismic stability criteria and to accommodate existing facilities, limited site access, seasonal reservoir operations, and environmentally sensitive areas within and adjacent to the Project site. Engineering analys...
Before seismic retrofits could be made to the Crane Valley Dam, in Madera County, California, a d... more Before seismic retrofits could be made to the Crane Valley Dam, in Madera County, California, a dewatering system had to be installed at the downstream toe of the structure. Because of the paramount importance of controlling hydraulic conditions immediately below the large dam, the design of the dewatering system required sophisticated groundwater modeling and careful attention to prevent problems associated with the artesian conditions and low-permeability soils present at the site.
Seismic retrofitting at Crane Valley Dam on Bass Lake in California required a dewatering system ... more Seismic retrofitting at Crane Valley Dam on Bass Lake in California required a dewatering system at the downstream toe of this large dam to facilitate a dry excavation. Although the excavation was only 1.5 to 4.6 m deep (but 152 m long), it was of paramount importance to control the artesian pressures, prevent breakout of seepage through the hydraulic fill embankment, and ensure a stable excavation subgrade, while the lake level remains 12 to 20 m higher than the excavation. The designers developed a system comprising ejector wells spaced 3 m on centers with 5 deep wells for the dewatering system. The system performed extremely well. Copious data was obtained on the flow rates in the ejectors and individual deep wells, piezometric levels in numerous piezometers, lake level and precipitation. The system remained in operation for over 10 months. This paper describes the interpretation of the data, groundwater modeling, the parameters controlling the design of the system, and the influence of the actual lake level and rainfall on the operation of the system.
Volume 1: Project Management; Design and Construction; Environmental Issues; GIS/Database Development; Innovative Projects and Emerging Issues; Operations and Maintenance; Pipelining in Northern Environments; Standards and Regulations, 2006
Geographic information systems (GIS) technology enables sophisticated, numerical-based mapping of... more Geographic information systems (GIS) technology enables sophisticated, numerical-based mapping of earthquake hazards, including liquefaction and landslide susceptibility, on a regional basis for pipeline systems. Existing earthquake hazard mapping was integrated ...
The Mw 6.3 Meinong earthquake, which struck southern Taiwan on February 6, 2016, was characterize... more The Mw 6.3 Meinong earthquake, which struck southern Taiwan on February 6, 2016, was characterized by an oblique left lateral strike-slip motion with a minor reverse component. The earthquake occurred at approximately 16 km depth on an unknown fault that did not rupture the ground surface, but rather produced a noticeable long period velocity pulse east to west, with the strongest amplitude motions recorded about 30km west of the epicentral region in Tainan City. Within this city, more than 20 multi-story buildings constructed under relatively modern building codes were severely damaged, including seven that suffered complete collapse. In addition, there was widespread damage associated with liquefaction, a substantial portion of which affected residential buildings causing large uniform and differential settlement, the later causing severe tilt to buildings in many cases. In response to this event, local earthquake professionals, faculty members, and students teamed with US NSF-spo...
Strasser, F. (2007). Estimates of VS30 values for the K-Net stations based on extrapolation of th... more Strasser, F. (2007). Estimates of VS30 values for the K-Net stations based on extrapolation of the velocity profile, personal communication. TEPCO (2007). Report on analysis of observed records at Kashiwazaki-Kariwa Nuclear Power Plant during the Niigata-Chuetsu-Oki earthquake 2007.
Crane Valley Dam is located on the North Fork of Willow Creek in Madera County, California, and i... more Crane Valley Dam is located on the North Fork of Willow Creek in Madera County, California, and is owned by Pacific Gas & Electric Company (PG&E). The results of seismic stability analyses performed in 2005 and 2006 showed that the dam’s hydraulic fill embankments would experience large deformations during and after the earthquake shaking postulated for the site. To improve the seismic stability and performance of the dam, PG&E initiated the Crane Valley Dam Seismic Retrofit Project (Project), which includes placing new rockfill buttresses on the upstream and downstream slopes of the dam, constructing internal drainage improvements, reinforcing portions of the dam’s concrete core wall, and raising the dam crest. Project components were designed to meet seepage control and seismic stability criteria and to accommodate existing facilities, limited site access, seasonal reservoir operations, and environmentally sensitive areas within and adjacent to the Project site. Engineering analys...
Before seismic retrofits could be made to the Crane Valley Dam, in Madera County, California, a d... more Before seismic retrofits could be made to the Crane Valley Dam, in Madera County, California, a dewatering system had to be installed at the downstream toe of the structure. Because of the paramount importance of controlling hydraulic conditions immediately below the large dam, the design of the dewatering system required sophisticated groundwater modeling and careful attention to prevent problems associated with the artesian conditions and low-permeability soils present at the site.
Seismic retrofitting at Crane Valley Dam on Bass Lake in California required a dewatering system ... more Seismic retrofitting at Crane Valley Dam on Bass Lake in California required a dewatering system at the downstream toe of this large dam to facilitate a dry excavation. Although the excavation was only 1.5 to 4.6 m deep (but 152 m long), it was of paramount importance to control the artesian pressures, prevent breakout of seepage through the hydraulic fill embankment, and ensure a stable excavation subgrade, while the lake level remains 12 to 20 m higher than the excavation. The designers developed a system comprising ejector wells spaced 3 m on centers with 5 deep wells for the dewatering system. The system performed extremely well. Copious data was obtained on the flow rates in the ejectors and individual deep wells, piezometric levels in numerous piezometers, lake level and precipitation. The system remained in operation for over 10 months. This paper describes the interpretation of the data, groundwater modeling, the parameters controlling the design of the system, and the influence of the actual lake level and rainfall on the operation of the system.
Volume 1: Project Management; Design and Construction; Environmental Issues; GIS/Database Development; Innovative Projects and Emerging Issues; Operations and Maintenance; Pipelining in Northern Environments; Standards and Regulations, 2006
Geographic information systems (GIS) technology enables sophisticated, numerical-based mapping of... more Geographic information systems (GIS) technology enables sophisticated, numerical-based mapping of earthquake hazards, including liquefaction and landslide susceptibility, on a regional basis for pipeline systems. Existing earthquake hazard mapping was integrated ...
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