Evaluating the behaviour of instrumented prototype rockfill dams

Abstract

This paper studies the behaviour of prototype rockfill dams under turbulent flow conditions to identify the flow-through characteristics of rockfill materials and examines conventional design principles. Two scales of prototype rockfill dams were studied. The first type of prototype tests included fifteen 0.5 m tall dams constructed with three different downstream slope angles. The dams were monitored for upstream and downstream water level, discharge rate, particle movement on the downstream face, and any noticeable failure (local or global) during the experiments. The second set of prototype tests included two 1.2 m tall dams constructed to study the internal hydraulic conditions and required a flow environment to initiate particle movements in rockfill structures. The results from the testing of small-dimension dams (mini-dams) provided understanding for developing the methodologies to optimize the design and construction of the scale-dam tests. The hydraulic performances of the scale-dams are presented using vibrating-wire piezometers measurements. Experimental data of the stage–discharge relationship are compared with predictive models, which show strong correlations.