The dredging efficiency decreases and the cutting force increases greatly for drag-heads on trailing suction hopper
dredgers (TSHD), which is mainly dominated by the dilatancy of densely compacted sand, so the soil for dredging is greatly
restricted. Based on FEM simulation, the dilatancy of dense sand was considered and the interactions of stress-strain-seepage
were coupled in the calculation of pore pressure in sand cutting. The numerical results illustrated that dilatation causes the
development of pore vacuum pressure at the front side of the blade in cutting water-saturated sand which results in an increase
of the grain stresses, resulting in higher cutting forces with higher cutting speed.