Based on the experimental data, an empirical formula for calculation of equivalent grain size of cohesive material in hydraulic model test is presented. Satisfactory result was obtained.

• 根据室内试验给出的粘土等价粒径经验公式，经与实际工程验证，符合程度尚好.；此外，用等价粒径法模拟三河闸下粘土局部冲刷，获得满意结果，可供类似工程参考