Abstract:Single-line method and double-line method are adopted respectively to carry out uniaxial compression tests on undisturbed loess(Q3) in the case of moistening or demoistening. By employing secant-modulus method,the experimental results from two methods are analyzed. It indicated that,whether double-line method or single-line method,the relation curves between secant modulus and pressure for unsoaked samples and soaked samples under the same initial moisture content can be considered as parallel,although there is a little difference between the slopes of the two curves. It is reasonable to fit the relation curve between secant-modulus difference and pressure by using exponential form.