塔基(桥墩)的局部冲刷问题是跨河工程规划、设计中需考虑的重要课题。受限于地形、地质、经济条件等因素,斜交塔基(桥墩)逐渐用于跨河工程中。然而,目前研究侧重正交塔基(桥墩)的局部冲刷问题,对斜交塔基局部冲刷规律研究较少,因此,以某斜交塔基工程为例,通过概化模型试验研究了斜交塔基的局部冲刷规律。研究结果表明:与正交塔基相比,斜交塔基偏向侧流速增幅大于塔基背向侧流速;冲刷坑最大冲刷深度较大,且最大冲刷位置位于塔基偏向侧;冲刷坑呈不对称的马蹄形,且塔基偏向侧冲刷范围大于背向侧;塔基防护后,以上趋势减弱。研究成果为解决跨江大桥或电缆通道建设中的斜交塔基局部冲刷问题提供了参考借鉴。

The local scour of tower footing (pier) is a critical subject in planning and designing river-crossing project. Skewed tower footing has being gradually used in river-crossing engineering due to special geography, geology and economic conditions. But researchers paid more attention to the local scour of orthogonal tower footing (pier) rather than that of skewed tower footing. In this article, the rules of local scour of a skewed tower footing are researched through generalized model test. Results reveal that the increment of flow velocity on deviational side of skewed tower footing is bigger than that on dorsal side; the maximum scour depth is large, and the position is on deviational side; the scour pit displays an asymmetrical horseshoe shape, and the scour range on deviational side is larger than that on dorsal side. When bed surface around the tower footing is protected, this trend becomes weak. The results offer reference for researches on the local scour of skewed tower footing of river-crossing bridge or cable gallery construction.