不同结构型式丁坝稳定性试验研究

Experimental study on stability of spur dike with different types

丁坝的稳定性直接影响航道整治工程的效果,选择稳定性较好的坝体结构型式及材料具有实际的工程应用价值。通过水槽试验首先从坝身横断面型式(梯形断面与圆弧断面)的角度,对比研究了散抛石坝的稳定性问题,指出同样的水流条件下,圆弧形横断面的结构型式具有更好的稳定性,并得到了散抛坝体出现水毁对应的边界条件。此外,对比研究了不同丁坝前后有水位落差时,混凝土与浆砌条石压载及混凝土块铰链排护面丁坝两种新坝型的稳定性,指出丁坝前后跌水高度是其水毁的重要制约因素之一。试验表明,后两种新型结构丁坝较散抛石坝具有更好的稳定性,可以在实际工程中加以推广和应用。

The stability of spur dike directly affects regulation effect of waterway harnessing project, and therefore it has practi- cal engineering meanings to choose more suitable structures and materials for the spur dike. Through flume test, firstly the stabili- ty of riprap spur dikes with different cross - sections were analyzed, it is pointed out that the spur dike with arc - shape cross - section is more stable under the same flow condition, and further the boundary condition of riprap spur dike damage was given. Then stability studies of two new types of spur dikes, dike surface covered by concrete hinge and masonry squared stone, were conducted respectively under different water level drops. It is concluded that the drop water height is a restriction factor for dike damage. It is demonstrated that these two new spur dikes possess better stability performance, which can be popularized and applied in practical engineering.