特高拱坝实际温度荷载与设计温度荷载在初次蓄水期有较大差别：一是承担封拱后温度回升荷载的结构形式不同，封拱后的温升仅作用于封拱之后的部分坝体而不是整体大坝；二是实测库水温与预测库水温不同，中下部高程实测库水温明显高于设计库水温。本文以二滩和小湾特高拱坝为例，研究设计温度荷载与真实温度荷载差异对特高拱坝的影响，并分析了真实温度荷载作用下小湾拱坝受力情况。结果表明，考虑坝体温度回升分层施加过程时，坝踵部位明显呈受压趋势；目前常用的库水温预测方法会低估坝体上游面受压程度。考虑真实温度荷载后得到的小湾拱坝坝踵应力结果与监测结果规律一致，数值相近，结果更为准确。%There are great differences between real and design temperature load of super-high arch dams during the first impoundment. First, the temperature of dam body will increase gradually after grouting, and the temperature recovery load acts only on the part that the transverse joints have already been grout-ed, rather than the whole dam. It is different from the consideration of design methods. Second, the mea-sured water temperature is obviously different from the predicted water temperature. For example, the mea-sured water temperature is much higher than the predicted water temperature at the lower part of the dam. Taking Ertan and Xiaowan arch dams as examples,the influence of the difference between the real and de-sign temperature load on the dam working performance is studied, and the stress state of Xiaowan arch dam is analyzed under real temperature load. The results show that the dam heel stress tends to be com-pressive with the dam layered process of temperature recovery considered. The compressive degree of up-stream face of the dam will be underestimated using the common methods of water temperature prediction at present. The dam heel stresses achieved considering real temperature load are consistent with the monitor-ing stresses of Xiaowan arch dam,and the value is close to each other,so the above methods is more ac-curate.
展开▼
