Question

Coastal Engineering:

(a) Solve for the critical shear stress using the Shields’ diagram for sand with D₅₀ = 0.30 mm, ?_s = 2650 kg/m³, with the water temperature equal to 20^oC.

(b) For a flow that generates a bed shear stress of ?_b= 0.4 N/m², will this sand move as bedload or in suspension according to the extended Shields’ diagram?

Answer 1

(a) Bed load transport rate theta (C_b/(rho_r - rho_w) g d_50) theta = 0.5/(2650 - 100) 9.81 (0.4 times 10^-3) theta = 0.077 (b) yes sand also be transported in suspicion.