To test the heat-transfer effect of the mixed buffer backfill material in the high-level radioactive waste geological repository

the model test was designed with reference to the actual size of each part of the high-level radioactive waste geological repository concept map combined with the numerical simulation of the repository heat source. The heat transfer

impermeability and strength have obvious advantages of the mix ratio of the "direct compaction method" and "stacking method" two model tests

get the heat transfer effect of the repository model under two masonry methods

discussed backfilling the heat transfer law of the repository model of the material under two masonry methods. Observing and comparing the heat transfer effects of the two masonry methods

it can be found that under the continuous influence of the central heat source

the moisture content of the buffer backfill material will change

which has different degrees of influence on its thermal conductivity and the integrity of the model; Compared with the "stacking method"

the temperature difference between the internal and external convergence of the model obtained by the "direct compaction method" is smaller

and the temperature convergence is faster. Therefore

it is recommended that when the backfill material of the repository is built

the size of the buffer backfill material should be increased as much as possible on the premise of ensuring the uniformity of the buffer backfill material and the quality of the project. The joints should be filled as densely as possible to reduce the thermal conductivity of the gap to the buffer backfill material and the impact of the tightness of the repository.