Summary: | 碩士 === 逢甲大學 === 土木工程學系 === 102 === This study identified the shear bands or shear kink-bands of rocks or backfills beneath the slabs and side-walls in the neighborhood and spillway of Renyitan Reservoir. Then we investigated the causes of spillway destructions in Renyitan Reservoir by the property of brittle fracture of rocks and soils in shear bands.
The result of this study shows that the rocks and backfills beneath the slabs and side-walls in the neighborhood and spillway of Renyitan Reservoir result in some shear bands or shear kink-bands because of the slides of active faults, spillway slabs and spillway side-walls. Due to the continuously increased brittle fracture in the rocks and soils of shear bands or shear kink-bands, reservoir water or rain water flow aggregately in the shear bands or shear kink-bands in a great quantity. Therefore, after the seepage is converted into pipe flow and the current speed is increased greatly, it results in the uplift destruction and piping destruction in the spillway of Renyitan Reservoir. In view of the critical effects of shear bands or shear kink-bands resulted from localizations of deformations on the spillway destruction of Renyitan Reservoir, it is suggested that the effects caused by shear bands or shear kink-bands should be considered in the seismic design of spillways in the future. It is also suggested that effective preventions for the slippage of the slabs and side-walls of spillways should be considered in the design of spillways, and relative displacements between side-walls and backfills and between backfills and original slopes after appropriate stiffeners are implemented should not be allowed to avoid Rankine active failure surfaces in the backfills.
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