Efficacy of the Combined Use of Bed Sill and Sacrificial Piles to Control Local Scour around Circular Bridge Piers

Table 4

Details of various combinations from the group of bed sill and sacrificial piles with geometric parameters and efficiency.

Test	Combined countermeasures	Geometric parameters of sacrificial piles					(cm)	(%)
		Arrangement of piles			X/D	α
C1	—	—	—	—	—	—	9	—
C2	Bed sill	—	—	—	—	—	7.4	17.8
C3	Sacrificial piles	Transverse	3	0.5	2	—	6.8	24.4
C4	Sacrificial piles	Transverse	5	0.83	2	—	7.55	16.1
C5	Bed sill and sacrificial piles	Transverse	3	0.5	2	—	5.4	40
C6	Bed sill and sacrificial piles	Transverse	5	0.83	2	—	6.15	31.7
C7	Sacrificial piles	Triangular	3	0.5	2.5	30°	5.65	37.2
C8	Sacrificial piles	Triangular	5	0.83	2.5	30°	5.8	35.6
C9	Bed sill and sacrificial piles	Triangular	3	0.5	2.5	30°	4.4	51.1
C10	Bed sill and sacrificial piles	Triangular	5	0.83	2.5	30°	4.7	47.8
C11	Sacrificial piles	Triangular	3	0.5	2.5	60°	7	22.2
C12	Sacrificial piles	Triangular	5	0.83	2.5	60°	7.5	16.7
C13	Bed sill and sacrificial piles	Triangular	3	0.5	2.5	60°	5.7	36.7
C14	Bed sill and sacrificial piles	Triangular	5	0.83	2.5	60°	6.35	29.4