Experimental Study on the Strength Characteristics of Frozen Clay on π Plane

A set of directional shearing tests using hollow cylinder apparatus (HCA) was carried out on remolded frozen clay at −6 °C to study the strength properties of frozen soils in π plane. During the shearing, the stress Lode angles was fixed at five different values (θσ = −30, −16.1, 0, 16.1 and 30°) under four mean principal stresses (p = 1, 3, 4.5 and 10 MPa). Through the tests, the strength locus of frozen soil in π plane with θσ ranging from −30 to 30° were gained experimentally for the first time. The test results show that the strength envelope of frozen clay changes from a curve-sided triangle to a circle with increasing p. And a combination of the Spatially Mobilized Plane (SMP) criterion and Mises criterion, the Generalized Non-linear strength theory, can better describe this strength envelope evolution law in π plane.