三板溪面板堆石坝面板裂缝成因分析

Causes for Cracks on Sanbanxi Concrete Face Rock-fill Dam

采用钢筋应力计、无应力计、应变计、温度计、裂缝计等监测仪器对三板溪混凝土面板堆石坝进行监测,研究三板溪混凝土面板堆石坝在施工期和运行期的应力、变形分布规律,分析混凝土面板产生结构性裂缝的可能原因。监测资料分析结果表明:导致面板水平施工缝挤压破损的直接原因是面板水平缝缝面压应力过大和结构上的缺陷;从外部运行环境看,首次蓄水水位上升过快引起大坝变形速率过大,面板偏心受压,最终导致面板水平缝挤压破损。

Some monitoring instruments such as reinforcement stress meters,non-stress meters,strain gauges,thermometers and crack meters are employed to monitor Sanbanxi Concrete Face Rock-fill Dam.The distribution rules of stress and deformation of Sanbanxi Concrete Face Rock-fill Dam during the construction and operation periods are studied.The possible causes for structural cracks are analyzed.The results of monitoring data show that the excess stress and structural defects are the direct causes for the crushing and breaking of horizontal construction joints.From the external operating environment,the excess deformation rate induced by the rapid rise of the water level during the first impoundment and the eccentric load on the panel eventually lead to the crushing and breaking of horizontal construction joints.