Physical Model Test and Heat Transfer Analysis on Backfilling Construction of Qinghai-Tibet Transmission Line Tower Foundation

The cone-cylindrical pile foundation is a kind of shallow buried foundation, which needs to be open excavated and backfilled during construction. density the backfill closely related refreezing process backfill. However, there still lack relevant research on relationship between method model experiment selected study under three soil densities. controlled 1.83, 1.62 1.36 g/cm3, times freeze–thaw cycle 14, 22 39, respectively. main findings are as follows: First, effect initial temperature mainly reflected in first cycles; second that higher backfill, faster responds changes outside air temperature, shorter freezing time; third, good conductor heat, will cause change side significantly greater than natural soil, surface results can provide reference for construction foundations cold regions selection boundary conditions numerical simulations.