Investigation for the deformation of embankment underlain by warm and ice-rich permafrost

The purpose of this study is to investigate the settlement of the embankment constructed in warm and ice-rich permafrost (WIRP) region along the Qinghai–Tibetan Railway (QTR). In this investigation, an in-situ experiment for the thermal regime under this embankment and for the settlement of the embankment is proposed. The data illustrate that the thicker the embankment fill, the thicker the WIRP layer under the embankment, and the greater the rise of the permafrost temperature, the larger the settlement of the embankment experiences. The observed data also show that the total settlement comes mainly from the creep deformation of the WIRP layer underneath the original permafrost table. To better understand this deformation, we construct a numerical model which considers the creep behavior of the WIRP layer to predict the settlement of this embankment. The numerical results show that 1) under the same mean annual ground temperatures (MAGT), the embankment settlement increases linearly with the thickness of the embankment, and 2) when the MAGT is at − 0.5 °C, the total settlement of the embankment with 6 m thickness would be up to 18.1 cm in the 30th service years of the embankment.