不同水力条件下圆柱桥墩局部冲刷试验研究

Experimental Study on Local Scour of Cylindrical Pier under Different Hydraulic Conditions

桥墩冲刷是导致桥梁水毁的主要原因,研究不同水力条件下局部冲刷对桥梁的影响具有重要意义。通过开展不同流速和水深下圆柱桥墩模型冲刷试验,研究了圆柱桥墩周围泥沙的局部冲刷发展规律,特别是流速和水深对桥墩局部冲刷的影响。试验研究表明:随着时间的发展,最大冲刷深度与冲刷坑范围在前期急剧发展,随后发展逐渐缓慢,直到冲刷处于近似平衡阶段。最大冲刷深度最开始出现在墩前侧方,随后始终出现在墩正前方附近,最小冲刷深度出现在墩的正后方附近,墩后的冲刷深度不足墩前深度的50%。流速和水深是影响桥墩的局部冲刷的关键因素,最大冲刷深度和冲刷坑的范围随着流速和水深增大而增大,相比于水深,冲刷深度和冲刷坑范围受流速的影响较大。

The local scour of pier is the main cause of bridge damage by water. It is of great significance to study the influence of local scour on bridges under different hydraulic conditions. Based on the flume scour test of cylindrical pier in difference flow velocity and water depth,this paper explores the local scour development around the cylindrical pier,especially the influence of flow velocity and water depth on the local scour. The experimental results showed that the maximum depth and scour hole range developed rapidly in the early stage. Then the development gradually slowed down until the local scour is in an approximate equilibrium stage. The maximum scour depth appeared on the side of the pier and eventually in front of the pier around. The minimum scour depth was directly behind the pier. The minimum scour depth behind the pier was less than 50% of the maximum scour depth. The flow velocity and water depth are the key factors affecting the local scour of the pier. The maximum scour depth and scour depth increases with the increase of velocity and depth of flow. Compared with water depth,the scour depth and scour hole range were affected more by flow velocity.