ANALYSIS OF A ZONED ROCKFILL DAM WITH CENTER CORE DURING CONSTRUCTION AND FIRST FILLING

摘要

We report simulation results for a zoned rockfill dam with center core during construction and first reservoir filling. In order to reproduce the generation and dissipation of pore water pressure in the core zone during construction, generation of buoyant forces due to filling and effective stress behavior, and elasto-plastic deformation behavior of a dam embankment under high overburden pressure peculiar to rockfill dams, we have applied a soil/water coupled consolidation analysis method to rockfill dams that incorporates an elasto visco-plastic model. We produced specimens of embankment materials, compacted them as on actual compaction ground and studied their mechanical properties and various parameters for analysis. For rock materials of a large grain size, we proposed a method of parameter correction to respond to the variance between in-situ and laboratory grain sizes. For calculating deformation during filling accurately, we examined characteristics of settlement due to submergence for embankment materials by tests and reflected them in analysis. We conducted a consecutive construction and filling analysis using models created to represent construction and first filling steps. Then we made a comparison between analytical results and actual measurements of settlement of the dam embankment due to construction, pore water pressures in the core zone and earth pressures in the dam embankment. As a result, we have confirmed that analytical results represented actual behavior fairly well, and proved that the proposed method was applicable to zoned rockfill dams with center core.