高温对混合型缓冲砌块渗透性能影响研究  

Influence of High Temperature on Permeability Performance of Bentonite-Sand Blocks

作　　者：周光平 张虎元[1,2] 沈秉成 徐千禧 李雪婷 柳霞飞 ZHOU Guangping;ZHANG Huyuan;SHEN Bingcheng;XU Qianxi;LI Xueting;LIU Xiafei(School of Civil Engineering and Mechanics,Lanzhou University,Lanzhou,Gansu 730000,China;Key Laboratory of Mechanics on Disaster and Environment in Western China,The Ministry of Education,Lanzhou University,Lanzhou,Gansu 730000,China)

机构地区：[1]兰州大学土木工程与力学学院,甘肃兰州730000 [2]兰州大学西部灾害与环境力学教育部重点实验室,甘肃兰州730000

出　　处：《世界核地质科学》2023年第S01期614-622,共9页World Nuclear Geoscience

基　　金：国家自然科学基金项目(编号:41972265)资助。

摘　　要：在高放废物地质处置库中,温度升高会改变缓冲材料的渗透性能。以混合型缓冲砌块为研究对象,在不同温度(25、60和90℃)和含盐度(蒸馏水DI、模拟北山地下水平均值和最大值)条件下进行渗透试验,测试其在Z、θ方向的水力传导系数K。结果表明:水力传导系数K随温度升高而增加,其中在常温条件下,K在10^(-12) m·s^(-1)数量级;而当温度从25℃升高到60或90℃时,K分别升高到1.49~1.76倍或1.09~2.45倍。混合型缓冲砌块的θ方向的K略大于Z方向的K,但不超过2倍,表现为各向同性。干燥状态试样的K值比保湿状态试样的K值高2~7倍,仍满足低于10^(-10) m·s^(-1)的高放废物处置缓冲材料防渗性能要求,干湿状态对水力传导系数影响不大。In high-level radioactive waste disposal facilities,increase of temperature can alter the permeability of buffer material.In this study,a bentonite-sand block was used as the research object,and infiltration experiments were conducted at different temperatures(25℃,60℃,90℃)and salinities(distilled water,synthetic Beishan ground water solutions with average salinity and maximum salinity)to test the hydraulic conductivity coefficient K in the axial(Z)and radial(θ)directions.The results showed that hydraulic conductivity increased with temperature,and under normal temperature conditions,K was in the range of 10-12 m·s^(-1).However,when the temperature was increased from 25℃to 60℃or 90℃,K increased by 1.49-1.76 or 1.09-2.45 times,respectively.The K in theθdirection of the mixed buffering block was slightly larger than that in the Z direction,but did not exceed 2 times.It indicated isotropy.Additionally,the K value of airdry samples was 2-7 times higher than that of fresh samples,while it still meets the anti-seepage performance requirement(<10-10 m·s^(-1)),air-dry and fresh have little effect on hudraulic conductivity.

关 键 词：混合型缓冲砌块 含盐度 水力传导系数 温度 各向同性 

分 类 号：TL942.211[核科学技术—辐射防护及环境保护]