Floating transportation resistance of bridge's square caissons

When the caisson is dragged on the surface of water,it is subjected to current forces.After calculating the value of viscous resistance of square steel caisson by using the calculation fluid software FLUENT,the numerical value of viscous resistance acting on the caisson's outer wall and the total caisson in the case of different current velocity and draft can be obtained;And by comparing the calculating results obtained from FLUENT with that from empirical formula,it's shown that the formula,regarding only the outer wall of the caisson as the water-breaking area,is not justified.In fact,the inner wall of caisson is also subjected to the viscous resistance and the forces can't be ignored.According to the calculating results obtained from FLUENT, the empirical formula can be modified by taking the forces acting on the inner wall into account.More correct results can be obtained using the modified empirical formula.And the modified experiential formula can provide references for engineering.