Technical ReportAbstract: In 1967, the Koyna mass concrete dam in India was seriously damaged by a magnitude 6.5 earthquake. The event is unique because the Koyna Dam is the only concrete dam to be significantly damaged due to ground shaking, and accelerometers at the site recorded time histories of the entire occurrence. The event provides researchers a classic problem for experimental studies and validating numerical procedures used to predict the seismic response of concrete gravity dams. This report comprehensively documents the construction and seismic testing of a 1/20-scale model of the Koyna dam, the largest scale model of the dam ever to be so tested. The model was tested to failure using sinusoidal motions, and the results can be effectively compared with analytical models as long as the effects of base rotations and material property variations are properly accounted for. The results of the sinusoidal wave test program are available for incorporation into possible future tests using scaled records from the 1967 earthquake. Additional formwork strengthening and stiffening is recommended for models used in any future testing conducted with a 1/20 scale model. Specific recommendations are offered to improve formwork integrity, model quality, and protection of test equipment and instrumentation.

Construction Engineering Research Laboratory (U.S.)Engineer Research and Development Center (U.S.)

Concrete gravity dams; Earthquake testing; Earthquake effects; Modeling; Materials testing; Koyna Dam; India; Seismic testing

ERDC TR ; 01-17.

Approved for public release; distribution is unlimited.

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