Organised by:
Hong Kong Regional Group
Venue:
G/F, Seminar Room, Civil Engineering & Development Building, 101 Princess Margaret Road, Ho Man Tin, Kowloon
Event status:
EVENT CLOSED
Speaker: Professor Oldrich Hungr, University of British Columbia, Canada
Time: 6.00 pm
Free Admission, no registration required
Synopsis
The name flowslide applies to a landslide that involves liquefaction due to the
structural collapse of the soil fabric. Flowslides can be extremely damaging, because they involve
sudden failure, high velocity and long runout. They occur during earthquakes, but also often
spontaneously, as a result of over-stress of collapse-susceptible soil.
Much of the existing literature dealing with flowslides relates specifically to known collapsesusceptible
soil types, including loose saturated sand or silt (loess), or extra-sensitive clay.
However, collapsive behavior may occur in a much wider range of soil types. Of particular interest
are flowslides that involve previously-disturbed soils (“colluvium”).
This lecture will present
several cases of major, fatal flowslides that occurred in colluvium formed by previous slow, ductile
landsliding. It appears that softening of the disturbed cohesive soil can dramatically change its
failure behavior. Thus, assumptions of ductile failure in a given material, even if backed by
previous site experience, may become disastrously incorrect. The most common soils involved in
these dangerous flowslides are low to moderate plasticity silty clays and silts. The provenance of
the examples is Canada, Western USA, Europe and South-East Asia.
About the Speaker
Professor Oldrich Hungr is a Professor of Geological Engineering at the University of British
Columbia in Canada. He is an eminent engineering geologist and is internationally recognized for
his research in landslide hazards. He has contributed significantly towards the modelling of
landslide behaviour with emphasis on debris dynamics, landslide hazards mapping, quantitative
hazard and risk assessment and design of remedial and protective measures. He is one of the
three members of the current Slope Safety Technical Review Board to advise the HKSAR
Government on technical aspects of slope safety.
Attendance certificate will be provided to participants after the Seminar. For enquiries, please contact Ir Dr Julian Kwan at [email protected].