The pH values in root surface soil were significantly lower than those in rhizosphere and bulk soil at heading,filling and harvesting stages,ranging from 5.

To the roots mechanical function, 2 calculation formula models, the shearing strength and anti-splitting strength model,were developed in the condition of surface soil reinforced with herb-root and slope anchored with taproot model.

Variation law of permeability coefficient during crack silting of earthfill dam clay blanket;

Calculation method for settlement and cracks of clay blanket;

In view of reservoir seepage, this paper puts forward the method of filling with silt to selfheal the clay blanket cracks of earth dam.