Long-term settlement of soft subsoil clay under rectangular or semi-sinusoidal repeated loading of low amplitude

By applying Yin and Graham's one-dimensional (1-D) equivalent-time rheological model, which can predict both primary and secondary settlement, the expressions for calculating the long-term subsoil settlement under rectangular or semi-sinusoidal repeated loading of low amplitude are obtained without considering the fluid-solid coupling. A property has been proven that ultimate settlement of clay is independent of stress increasing history under 1-D conditions. According to this property, the expressions are derived considering the solid-fluid coupling to approximately calculate the long-term total settlement and the long-term settlement of soft subsoil clay after construction of the road embankment. Because the expressions of the long-term settlement are analytical solutions in the present paper, they can not only avoid cumulative calculation errors in the numerical analysis, but also have more solid theoretical foundations than empirical equations.