When the typhoon floods, the impact of oblique flow is an important factor that causes the embankment toe to be dumped and even cause the disaster. In order to understand the scouring potential of the oblique flow during flooding and propose appropriate toe protection of embankment, the experiments are implemented in three stages with 9-year plan (2012~2020).
A hydraulic flume model test with different oblique flow angles of attack (i.e. 30o, 60o, 75o, as shown in Figure 1 to Figure 3) was built in the laboratory to carry out a series of fundamental experiments with combination for toe scouring and protection arrangement (Figure 4).
Figure.1 The first stage (2012~2014) 30o oblique flow flume plane
Figure.2 The second stage (2015~2017) 60o oblique flow flume plane
Figure.3 The third stage (2018~2020) 75o oblique flow flume plane
(a) Stage 1 fixed-bed test
(b) Stage 1 movable-bed test
(c) Stage 1 protection test
(d) Stage 2 fixed-bed test
(e) Stage 2 movable-bed test
(f) Stage 2 protection test
(g) Stage 3 movable-bed test
(h) Stage 3 movable-bed test
(i) Stage 3 protection test
Figure.4 Experimental photo
It is expected to obtain the short-term general scour, maximum toe scour of different oblique flow angles of attack as shown in Figure 5 and Figure 6, and to propose its proper toe protection arrangement (Figure 7 and Figure 8). These results can provide practical application of relevant engineering planning and design.
Figure.5 Comparisons of maximum toe scour of the 30o oblique flow and general scour
Figure.6 Comparisons of maximum toe scour of the 60o oblique flow and general scour
Figure.7 Design of the layout of the toe protection block for the 30o oblique flow
Figure.8 Design of the layout of the toe protection block for the 60o oblique flow