The effect of width opening downstream of chute structure on the depth and the dimensions of downstream scour hole was investigated using a physical model in the presence of two different block geometries, including a USBR block and a lattice block installed on chute. For this purpose, five chute structures with baffled blocks were designed and constructed, including three models with a divergence ratio of 1.45, 1.75, and 2.45, including a USBR block and 2 models without divergence with a divergence ratio of 1, including USBR and lattice blocks. The results increase the chute widening ratio from 1 to 2.45 reduced the mean and maximum depths and the mean and maximum lengths of scour pit, while enhancing the flow energy dissipation along the chute. Besides, using perforated piers increased the length of scour pit, while reducing its depth and the relative flow energy dissipation.

在存在两种不同几何形状的块（包括 USBR 块和安装在溜槽上的格子块）的情况下，使用物理模型研究了溜槽结构下游的宽度开口对下游冲刷孔的深度和尺寸的影响。为此，设计并建造了5个带挡板的溜槽结构，包括发散比为1.45、1.75和2.45的三个模型，包括USBR块和2个发散比为1的无发散模型，包括USBR和格子块。结果表明，将溜槽加宽比从1增加到2.45，减小了冲刷坑的平均和最大深度以及平均和最大长度，同时增强了沿溜槽的流动能量耗散。此外，使用穿孔墩增加了冲刷坑的长度，