The scour limit depth around spur dikes is very important for calculating the base depth of objects and it is a key factor in designing and working.

Justice is not only a systematic concept but also a scope of people's values and spiritual belief. The base and core of justice is equitable to respect and protect rights to the maximum limit.

According to diffuse instability criterion, worked out the principle of verdicting the case of base fracture or side fracture and formulae of fracture limit BHF;