谷幅变形对白鹤滩水电站反拱底板水垫塘应力状态的影响分析

目前，国内外一些高拱坝工程在蓄水后已有谷幅变形的现象产生，谷幅变形不但影响拱坝性态变化，已有实例还表明其可能影响到下游消能建筑物的正常运行。为分析谷幅变形对白鹤滩水电站消能建筑物运行状态的影响，运用边界位移法进行有限元分析，模拟不同谷幅变形量作用下反拱底板水垫塘无水检修工况及正常运行工况的应力状态，分析弹性结构缝的不同布置方式对水垫塘在谷幅变形作用下应力状态的影响。结果表明：随着谷幅变形量的增加，水垫塘的应力也不断增大；当水垫塘顶部的谷幅变形量不大于50 mm时，无缝结构水垫塘的安全是可控的，且蓄水可以减小谷幅变形对水垫塘结构不利应力的影响，设置弹性结构缝可能会增大其不利应力。

Influence of valley deformation on the stress state of Baihetan plunge pool with an inverted-arch slab

At present, some high arch dam projects in the domestic and overseas have already experienced the phenomenon of valley deformation after impoundment, which not only affects the change of arch dam properties, but also has been proven to affect the normal operation of the downstream energy dissipation buildings. In order to analyze the effect of valley deformation on the operation of energy dissipation buildings in Baihetan Hydropower Station, we adopted the boundary displacement method for the finite element analysis, simulated the stress state of the plunge pool with an inverted-arch slab under maintenance condition (no water) and normal operation condition with different valley deformation amplitudes, and analyzed the effect of different arrangements of elastic joints on the stress state of the plunge pool under the effect of valley deformation. The results show that with the increase of valley deformation, the stress of the pool also increases; when the valley deformation of the top of the pool is less than or equal to 50 mm, the safety of the plunge pool with a seamless structure is in control, and the impoundment can further reduce the influence of valley deformation on the adverse stress of the pool structure, whereas the setting of elastic joints may increase its adverse stress.