 K0 can be obtained directly in the field based on e.g.the dilatometer test (DMT) or a borehole pressuremeter test (PMT), although it is more commonly calculated using the well-known Jaky's formula.For loosely deposited sands at rest, Jaky showed analytically that Ko deviates from unity with downward trend as the sinusoidal term of the internal friction angle of material increases, i.e.