Membrane penetration is the most important factor influencing the measurement of volume change in triaxial consolidated-drained shear test. It has proved that the effective pressure

average particle diameter

thickness of membrane elastic modulus of membrane

contact area between membrane and soil particle and initial void ratio are the major factors influencing membrane penetration. According to the deformation model given by Kramer et al. the analytic solution of the membrane penetration considering the initial void ratio is deduced using the energy conservation law based on the basic equations from theory of plates and shells as well as the elastic mechanics. Membrane penetration volumes are deduced from isotropic consolidation tests by the method of embedding different diameters of iron rods in the triaxial samples. The differences between the analytic solution and test result are analyzed. In general

the results from the analytic solution are considerably agree well with the test data.