Located on the Waikato River in Waikato County, New Zealand, Karapiro
Dam is a variable radius arch dam with a crest length of 578 ft
and a maximum height of 182 ft measured at the crown cantilever.
The dam was designed using the "trial load" method of
arch dam analysis. It consists of an arch structure supported
by a thrust block and gravity sections on the left abutment and
an intake structure on the right abutment.
Three-dimensional
finite-element verification analyses were performed to evaluate
seismic safety of Karapiro Dam. The structural stability of the
dam for the static and seismic loading conditions was assessed
and factors of safety against sliding along various potential
failure planes were determined. The verification analyses of the
dam involved review of the previous studies, development of analysis
and evaluation criteria, determination of loading conditions,
and a 3D finite-element model which included the arch section
and the associated thrust block and gravity section, foundation
rock, and the impounded water. The foundation model for Karapiro
Dam was constructed on the basis of the surface topography of
the canyon. The orthotropic linear-elastic material properties
were assumed for the foundation rock, which varied across several
foundation rock zones.
In
addition to verification analyses, Quest Structures also provided
technical advisory services to Electricity Corporation of New
Zealand on structural engineering, safety evaluation, and design
of remediation conducted by others.
