内蒙古丰泰电厂贮灰坝面板治理研究

在我国北方地区许多燃煤发电厂的贮灰坝为粉煤灰坝体,在冬季运行期间,由于低温在坝内形成冰层,经常发生冰层冻胀并挤压灰坝混凝土护坡面板,导致面板滑移和土工布开裂。当气温回升时,风浪通过破裂的土工布迅速淘蚀灰坝内的粉煤灰,使坝体发生严重的坍塌破坏。为解决生产及工程实际难题,作者分析了灰坝面板材料的病害成因、与冰层间的冻结特性,对修补技术及修补材料进行了研究与对比,提出了采用PVC卷材覆盖面板的方法,可避免混凝土护坡面板被挤压受损。2006年3月,结合内蒙古丰泰电厂贮灰场近200m长遭到严重损坏的坝段,进行了修复试验。试验选用了PVC卷材覆盖面板,经当年冬季观察,起到了抗冰层冻胀挤压作用。经3年的运行,坝体及面板未出现冻胀损坏现象,贮灰场运转正常。实践证明这项技术是成功的,可用于寒冷地区粉煤灰坝及其它水工混凝土面板的保护。

Study on slab repairing for a ash dam in Fengtai Power Plant in Inner Mongolia

Many dams of coal ash storage yard in power plants in northern China are made of coal fly ash. During winter a thick ice layer would be formed inside the dam body due to negative temperature, resulting in frost heave. Ice would push and squeeze concrete protect ion slabs on the ash dam, causing slabs and geotextiles to break and collapse. When temperature rises, water waves in the reservoir would wash away ashes from dam through the outworn geotextiles. The author analyzed the damaging causes in terms of slabs material and characteristics of ice layer freezing and studied the existing repairing materials and repairing technology. A new method of using PVC covering material on the slabs was put forward to avoid ice extrusion and damage. In March of 2006, a test was conducted to repair a 200m long dam seriously damaged in the Fengtai Power Plant in Inner Mongolia by applying the method. Field observations in the winter of that year and 3 years latter showed that the material played a part in resisting frost heave and ice extrusion without frost heave damage. The coal ash storage yard was in normal operation.