“…Unsaturated soils widely distribute around the world, such as deep geological disposals Birkholzer et al, 2018), semi-arid / arid zones (Agam et al, 2004;Pfletschinger et al, 2012), and coastal regions (Gerscovich et al, 2006;Saghravani et al, 2016). During the service of geotechnical and geo-environmental engineering facilities working under high temperature, e.g., nuclear waste repositories (Wang et al, 2016;Birkholzer et al, 2018), heated pipelines (Zhao et al, 2014;Zhu et al, 2020) and energy piles (Laloui and Di Donna, 2013;Zheng et al, 2016), heat transfers to the surrounding soils, causing thermal expansion of pore gas, liquid and solid, as shown in Fig. 1.…”