Numerical simulation of efficient cooling by coupled RR and TCPT on railway embankments in permafrost regions

Coupled strengthening measures of ripped-rock (RR) revetment and two-phase closed thermosyphons (TCPTs), referred to as CRRTs, have proved to be effective in solving the thaw-induced problems in engineering constructions in permafrost regions. However, one of the key issues is related to the effectiveness of the current CRRT systems in the long term. In this paper, a coupled strengthening model with a CRRT is established to rebuild and forecast the geo-temperature distribution before and after the reinforcement. The geothermal conditions are recorded for three cases: a heat insulating embankment reinforced with RRs and vertically implemented TPCTs, a heat insulating embankment and general embankment reinforced with CRRT in which the TCPTs are vertically implemented, and a heat insulating embankment and general embankment reinforced with CRRT in which the TPCTs on the sunny shoulder are inclined at an angle based on the practical configuration of the embankment. Some corresponding conclusions and suggestions are proposed for a better design of CRRTs for the construction and possible reinforcement of railway embankments in permafrost regions.