SOIL TESTING APPARATUS FOR VARIOUS STRESS PATH TESTS UNDER PLANE STRAIN CONDITION

A soil testing apparatus for various stress tests under a plane strain condition is provided to perform tests of various stress paths by accurately measuring the volume deformation and the gap pressure of a sample. A soil testing apparatus includes a housing providing a closed space, a sampler installed in the housing, on which a sample is positioned, and a pressing unit providing a pressure into the housing. The sampler includes two side walls(142), a lower cap, an upper cap, an inner membrane(152), an outer membrane(154), and gap pressure pipes(L1,L2). The side walls support a sample on both sides thereof. The lower cap blocks a lower portion between the side walls. The upper cap blocks an upper portion between the side walls to press the sample. The inner membrane surrounds a side surface of the sample. The outer membrane surrounds the outer surface between the lower cap and the upper cap. The gap pressure pipe is connected to the sample from the outside of the housing.