Improving the pressuremeter approach for settlement calculation under high-speed railway embankments

Consolidation settlement under embankment is often calculated using the oedometric approach. However, engineers tend to conduct these calculations in clays based on in situ test results including the pressuremeter measurements. The pressuremeter method is based on Menard's rheological coefficient, enabling to shift from the pressuremeter modulus to the oedometric one. This relationship has demonstrated some prominent success when estimating consolidation settlements within a defined stress domain. This paper addresses improvements in this method for settlement calculation in overconsolidated terrain. For this purpose, the authors suggest two expressions for the rheological coefficient based on back-calculation together with a linear and nonlinear multiple regression. The results indicate that using the rheological coefficients proposed in this study gives settlements approximating the measured ones compared to the rheological coefficients reported in the literature. The authors have also established an adjusting coefficient to be introduced as part of the common pressuremeter settlement expression for approximating the measured values on-site.