USGS - science for a changing world

Pacific Coastal and Marine Science Center

PCMSC Seminar Series

Screen shot from Rob's upcoming talk.Seismic Soil Liquefaction Assessment by Shear Wave Velocity

Robert Kayen
Research Civil Engineer at USGS PCMSC, and Adjunct Professor at UCLA

Weds., January 28, 2015, 2:00 pm

ABSTRACT:
Soil liquefaction occurs when loose, saturated soil loses strength and stiffness in response to earthquake stresses and behaves like a liquid. If large earthquake stresses are rapidly applied the excess pore water pressures may rise and cause soil to lose all of strength, damaging structures built on or within it. Liquefied soil may flow like a liquid damaging large areas of habitation or industry.
This talk describes a new method to assess the seismic resistance of soil to liquefaction by measurement of the shear wave velocity (Vs) of soil layers. This study presents the results of an eleven-year international project to gather new Vs site data for 301 new liquefaction field case histories in China, Japan, Taiwan, Greece and the USA combined with previously published case histories. The method for collecting the Vs velocity profiles uses non-invasive advanced geophysical techniques based on the dispersive properties of surface waves. From these data, probabilistic correlations are presented for seismic soil liquefaction occurrence. The new dataset and probabilistic analysis also help resolve the ancillary issues of how soil texture effects liquefaction potential, and how to scale the estimated stress for earthquake duration and magnitude.

See a list of all Seminars previously presented.


Directions and Parking

Street map of our location.
[Larger version]

From the San Francisco Bay Area:
Take your favorite highway to Hwy 17 South to Hwy 1
At the Hwys 17+1 merge, keep right
Follow signs to “Hwy 1 North, Half Moon Bay, UC Santa Cruz”
Stay on Hwy 1 North (keep in right-most lanes)
Hwy 1 is also named Mission St. — Follow Mission for about 2 miles
At the Western Drive stop light, turn left onto Western Drive
The building right in front of you is the
USGS Pacific Coastal and Marine Science Center
2885 Mission St. Extension
at the intersection of Western and Mission St. Extension

From the south coast:
Take Hwy 1 North to west Santa Cruz
At the Western Drive stop light, turn left onto Western
The building right in front of you is the USGS Pacific Coastal and Marine Science Center, at the intersection of Western and Mission St. Extension

From the north coast:
Take Hwy 1 South to west Santa Cruz
At the Western Drive stop light, turn right onto Western
The building right in front of you is the
USGS Pacific Coastal and Marine Science Center
2885 Mission St. Extension
at the intersection of Western and Mission St. Extension

Parking:
You may park in the parking lot located on the NE corner of Western Drive and Mission St. Extension
Limited parking is available along Mission St. Extension and along Natural Bridges Drive
Entrance to PCMSC is at 2885 Mission St. Extension (small green star with arrow, on the map), at the intersection of Western and Mission St. Extension

Photograph of Natural Bridges, photo by Laura Torresan. 

Schedule

Weds., January 28, 2015, 2:00 pm

Rob Kayen

USGS PCMSC Research Civil Engineer

Seismic Soil Liquefaction Assessment by Shear Wave Velocity

Weds., February 4, 2015, 2:00 pm

Eric Geist

USGS PCMSC Research Geophysicist

Weds., March 18, 2015, 2:00 pm

Tom Parsons

USGS PCMSC Research Geophysicist

 

 

 

 

How to find our Seminar Room

Schematic shows how to get to the PCMSC seminar room.

Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://walrus.wr.usgs.gov/seminar/
Page Contact Information: Laura Zink Torresan
Page Last Modified: 22 January 2015 (lzt)