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Dams
Published in Mohammad Albaji, Introduction to Water Engineering, Hydrology, and Irrigation, 2022
A gravity dam can be combined with an arch dam into an arch-gravity dam for areas with massive amounts of water flow but less material available for a pure gravity dam. The inwards compression of the dam by the water reduces the lateral (horizontal) force acting on the dam. Thus, the gravitation force required by the dam is lessened, i.e. the dam does not need to be so massive. This enables thinner dams and saves resources (Figure 3.5).
RCC Arch Dams
Published in Nathalie Schauner, Icold Committee on Concrete Dams, 2020
As a result of their simple configuration and modest stress levels, arch-gravity and curved-gravity dam structures are generally well suited to construction in RCC. While an arch-gravity dam will offer advantages over a gravity dam in reduced concrete volume, consideration must be given to some additional complexities, with potentially increased time and cost, as a consequence of a possible requirement for groutable induced transverse joints and increased pre-cooling and/or post-cooling.
Effect of abutment movements on nonlinear seismic response of an arch dam
Published in Structure and Infrastructure Engineering, 2020
The abnormal phenomenon of abutment movement that exhibits a reduction of the valley width has been reported in several arch dams. The 132 m high Beauregard arch-gravity dam was built between 1951 and 1960 in Italy. The dam was observed to deflect upstream and crack on the downstream face after the filling of the reservoir, which was caused by the compression induced by the left bank movement according to the study by Frigerio and Mazzà (2014). Demolition of the upper part of the dam was chosen as the rehabilitation solution to guarantee a long-term safety operation of the Beauregard dam. The 156 high Zeuzier arch dam, put in operation in 1957 in Switzerland, exhibited the similarly strange behaviour after the 21-year normal operation without any problem. A sudden upstream movement of the crest of the dam axis was observed in the fall of 1978 and the nonreversible upstream displacements continued developing. In addition, cracks formed along the downstream foundation line and contraction joints opened on the upstream face. The problem is recognized to be caused by the excavation of an exploratory adit with a distance of 1.5 km from the dam, which lowered the groundwater table and resulted in a vertical settlement of dam foundation and a closing of the valley (Lombardi, 2004). Several other high arch dams have also been experiencing the influence of a closing of the valley after the first filling of the reservoir, for instance, the Jinping-I arch dam built in 2013 (Cheng, Liu, Yang, Pan, & Lv, 2017) and the Xiluodu arch dam completed in 2014 (Liang, Hu, Fan, & Li, 2016) in China. The abutment movement affected the arch dams behaves in an elastic way currently, but the horizontal deformation of the valley near the dam still develops and the closing of the valley at the dam section does not yet stabilize. Some studies (Cheng, Liu, Yang, Pan, & Lv, 2017; Liang, Hu, Fan, & Li, 2016; Liu, Xiang, Fan, Li, & Ma, 2017) have been carried out to understand the mechanism of the deformation of the valley, but no consensus has been reached.