乌东德双曲拱坝泄洪中孔牛腿施工测量技术

Construction Survey Technology of Mid-hole Bracket for Flood Discharge of Wudongde Hyperbolic Arch Dam

乌东德水电站泄洪中孔体形复杂,在中孔的进出口即大坝的上下游面分别布置牛腿。除与大坝交线部分,牛腿以中孔轴线为对称轴左右对称,且呈矩形,中孔进口边墙左右由1/4椭圆布置成喇叭口,出口边墙布置成梯形喇叭口,中孔进口底板高程不一致,牛腿与大坝交线均不在同一高程面,大坝牛腿的位置正确性是十分重要的测量研究质量指标,为保障大坝牛腿顺利安装施工,测量技术人员全程参与控制网点的加密布设、施工放样、过程质量检查及最终的验收,取得了较好的成果。

The shape of mid-hole for flood discharge of Wudongde Hydropower Station is complicated,and brackets are arranged on the upstream and downstream sides of the dam.Except for the section intersecting the dam,the brackets are symmetrical about the axis of the middle hole and rectangular.The left and right side walls of the entrance of the mid-hole are arranged into horns by 1/4 ellipse.The outlet side walls are arranged with trapezoidal horns.The elevation of bottom plate at the entrance of mid-hole is inconsistent,and the intersection line between brackets and dam is not on the same elevation surface.The correctness of dam bracket position is an important quality index for measurement and research.In order to ensure the smooth installation and construction of dam brackets,surveying technicians have participated in the whole process of encrypting layout,construction lofting,process quality inspection and final acceptance of control points,and achieved good results.