D-BAUG - Departement Bau, Umwelt und Geomatik - ETH Zürich

Highlights ▪ Infrastructure Systems / Highlights ▪ Resources
In situ tests on steel deck concrete
composite slabs at Zurich International
Airport
Is the load bearing capacity after 35 years in
service still sufficient?
by M. Klippel, M. Knobloch, M. Fontana / IBK
Terminal B at Zurich International Airport has been used by
millions of tourists and business people. To implement
the European Schengen agreement, the terminal has to be
reconstructed after 35 years in service (Fig. 1).
The terminal was built in 1974, basically as a steel frame
construction with profiled steel sheeting as supporting
structure. Does this structure still meet the current safety
and serviceability standards or will it have to be replaced?
The decision regarding demolition or modification, with all
the associated economic and ecologic effects, has to be
based on a firm foundation. Generally, how does the loadbearing
behaviour of composite constructions change over
the years? How appropriate are our design rules for assessing
the capacity of existing and intensely used structures?
The bond between steel sheeting and concrete is the critical
factor for the load-bearing capacity of composite slabs.
How has the bond between the concrete and the steel
changed during 35 years of intensive use? Is it still sufficient?
To clarify this and further questions, large-scale tests
were performed in situ on the composite slabs at Zurich International
Airport (Fig. 2).
Useful data was generated by these tests to enable the assessment
of the composite slabs. The tests showed that a
sufficient bond still exists between the steel sheets and the
concrete and that current design rules properly assess the
load-bearing capacity of structures after long-term use.
60 ▪ D-BAUG Annual Report 2009
Shear band propagation in soils as a
mechanism of tsunamigenic landslides
Via physical tests an analytical model has
been validated which provides an approach
to calculate initial landslide velocity of sub-
merged tsunamigenic landslides.
by E. Saurer, A. M. Puzrin / IGT
Conventional geotechnical methods to analyze the failure
mechanisms of submerged slides tend to underestimate
the real height of the resulting tsunami wave. In this
study, an approach has been developed, which includes
dynamic analysis of the landslide mechanism. This approach
accounts for an initial landslide velocity, which justifies
larger tsunami wave height predictions.
The analytical model is based on the phenomenon of progressive
and catastrophic shear band propagation in soils
and on the energy balance approach from fracture mechanics.
In order to validate this model, the rate of the
progressive shear band propagation has been studied using
physical trapdoor- and shear-blade tests and compared
to the analytical solution (Fig. 5a, 5b).
When applied to the dynamic process of catastrophic shear
band propagation in slides, this energy balance approach
allowed for an analytical solution for the initial landslide
velocity to be derived (Fig. 6a).
Application of the obtained analytical solution to historic
and recent submerged landslides, such as the Weggis slide
in Lake Lucerne (Fig. 6b), confirmed that this approach is an
appropriate tool to explain more realistic tsunami wave
heights.