Professor, The University of Western Ontario, London, Ontario
Senior research engineer, Technology Research Center, Taisii Corporation, Yokohama,
Supervising engineer, Geotechnical Design, Ontario Hydro, Toronto, Ontario
Senior geotechnical specialist, Ontario Hydro, Toronto, Ontario
A long-term dam safety program has been initiated by Ontario Hydro to evaluate the safety of existing dams. Most of the dams in operation were constructed between 1910 and 1975. The larger dams are often of the concrete gravity type founded on rock.
As an integral part of this program, laboratory methods for the measurement of the complete strength envelope of bonded concrete-rock contact and strength parameters of unbonded contact have been developed. The principal method and interpretation of each type of test are described in this paper. Typical results of tests on samples of dam-foundation interface recovered from existing dams are presented. The methods developed enable the determination of the strength envelope appropriate for the working stress level during operation of dams and the direct measurement of tensile strength and cohesion, thus removing the uncertainty of extrapolation for the cohesion component of strength in conventional triaxial and direct shear tests.
Paper ID: GTJ10206J