Prediction method for tensile strength of unsaturated cohesive soil

The invention discloses a method for predicting the tensile strength of unsaturated cohesive soil, which comprises the following steps: establishing a soil particle ideal contact model, enabling soil particles to be tiny ideal spheres and to be in close contact with each other, and enabling pore liquid among the soil particles to be pure water; s2, carrying out stress analysis on each component of the soil particle ideal contact model in the step S1, and calculating a wet absorption stress expression among soil particles; replacing the surface tension of the wet absorption stress expression among the soil particles in the step S2; s2, deducing a geometrical relationship of the ideal contact model of the soil particles in the step S1, and in combination with the step S3, representing a wet absorption stress expression among the soil particles by using a filling angle beta; in combination with an equal-diameter sphere space filling theory, calculating a relationship between a filling angle and dry density and a