弯道丁坝防冰结构布置形式试验研究

弯曲河流的凹岸易受到冰排的撞击而发生磨蚀、崩岸，该处的护岸工程也会在冰排撞击作用下发生破坏，丧失防护功能。研究冰排的运动规律，进而保护河岸意义重大。丁坝作为治河建筑物会明显改变水流条件，而冰排随水流而动，丁坝的存在必然会对冰排的运动产生影响。通过室内试验的方法研究了在河流凹岸布置丁坝后冰排的运动特性，比较了5种不同丁坝布置形式对冰排运动的影响。试验研究表明:从防冰效果看，双丁坝的布置方案要优于单丁坝布置方案；单丁坝布置方案中，弯道60°布置位置最佳；弯道首、尾部的双丁坝布置形式中，长丁坝的布置形式较短丁坝布置形式效果更好；在弯道后加置1~2个短丁坝可以使双丁坝布置形式的防护效果达到最佳。

Experimental study of layout of spur dike as ice-proof structure in curved channel

The concave bank of curved channel is easily eroded or collapsed under the impact of ice floes, and its bank revetment will also be damaged and lose its function of protection under the impact of ice floes. If it happens to a boundary river, the riverbank retreat caused by impact of ice floes means the loss of national territory. So the study of the pattern of ice floes movements has essential meaning in the protection of river banks. The spur dikes as river control constructions can significantly change flow conditions. As ice floes move with water flows, the existence of spur dikes will inevitably influence the movements of ice floes. The characteristics of ice floes movements after layout spur dikes at the concave bank of curved channel are studied through laboratory experiments. The influences of ice floes movements of five different layout types of spur dikes are compared. The research results show that, the double spur dike layout is superior to the single spur dike layout in ice defense effect; in the single spur dike layout the best layout position is 60 degree of the curved channel; the long spur dike is superior to the short spur dike in double spur layout of the head and rear of the curved channel; the add of 1~ 2 short spur dikes at the back of the curved channel will optimize the protection effect of the double spur dike layout.