ZHANG J M, QI X J, WANG Y J,et al.Permeability and mechanical properties of buffer materials under optimal proportion[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(4):190-198.

doi:10.16186/j.cnki.1673-9787.2024060024

Received:2024/06/13

Revised:2024/08/27

Published:2026/06/17

Permeability and mechanical properties of buffer materials under optimal proportion

Zhang Jiaming1, Qi Xiaojian1, Wang Yujie1, Zhao Jia1, Nan Gan1, Hou Xinyu1, Xiong Qiuling2

1.Faculty of Engineering， China University of Geosciences， Wuhan  430074， Hubei， China;2.School of Construction Engineering， Jilin University， Changchun  130000， Jilin， China

Abstract: Objectives To safely dispose of the large amount of radioactive waste generated by nuclear energy， the permeability and mechanical properties of barrier materials under optimal proportions were investigated.  Methods The main properties of bentonite-gravel-sand buffer materials under the optimal proportion were studied， including the relationship between the material proportion and the maximum bulk density. Simulation tests were carried out to explore the bearing capacity and permeability of an artificial simulated foundation.  Results The results show that the maximum bulk density of the material is positively correlated with the fine particle content within a certain range. When the fine particle content increases from 5% to 20%， the maximum bulk density increases. The maximum dry density of the material is related to the bentonite content and water content. The lower the bentonite content，the lower the maximum dry density； the higher the water content， the lower the maximum dry density. Under high compaction， the buffer material exhibits high foundation bearing capacity， with no proportional limit in the bearing capacity curve， and a low permeability coefficient. The average permeability coefficient is 1.577 8×10^-5 cm/s，indicating a weak permeable layer with good impermeability.  Conclusions The optimal proportion of the buffer material is related to the content of each component， mainly controlling the maximum dry density by affecting the porosity of the material. The optimal proportion is 10% bentonite + 24.4% manufactured sand + 65.6% gravel. The bearing capacity of the buffer material is related to its compactness. Under the optimal proportion， the buffer material exhibits high bearing capacity and better impermeability， and is classified as a weak permeable layer.

Key words:bentonite;foundation bearing capacity;permeability coefficient;radioactive waste