The relationship between in-situ values of soil shear strength and laboratory experimental values is discussed. Based on consolidation theory of saturated soil

the consolidation of soil is the process effective stress increasing and pore water pressure dissipating under a certain pressure action. With the effective stress increasing

void ratio of soil decreases and shear strength increases. Compression curve and shear strength line have one-to-one correspondence relationship. Based on in-situ compression curves and indoor experimental curves

variation regularity of soil shear strength during loading and unloading processes is studied. Then

the relationship between cohesion and internal friction angle is derived based on the calculation method of soil unloading shear strength. Finally

the calculation method of shear strength for intact soil is obtained.