摘要
当砾石土防渗体出现裂缝时,土石坝防渗体的抗渗能力主要依赖于反滤料对防渗料的保护。利用自行研制的环状径向渗透仪,采用不同级配反滤料与含有不同裂缝长度的砾石土防渗料组合进行反滤试验研究。根据断面平均渗透系数的变化规律探讨砾石土防渗料裂缝自愈的条件和机理,提出了裂缝砾石土在反滤料保护下进行渗流量计算的初步方法。研究表明,含裂缝砾石土的渗透性随裂缝长度的增大而增大,但裂缝长度及裂缝的存在与否对砾石土的自愈和次生反滤层的形成无影响。含裂缝砾石土防渗料比含裂缝普通粘土防渗料的抗渗强度高。次生反滤层形成时的水力坡降随反滤料特征粒径D20的减小而增大。计算含裂缝砾石土的渗流量时应考虑裂缝面周围松动带范围及其渗透性。
The self-developed annular radial permeameter was used to investigate the protection effect of the filers having different gradations on the gravelly clayey soils having different cracks. The criteria and mechanism of crack self-healing for gravelly clayey soils were discussed based on the changes in the coefficient of permeability with the hydraulic gradient. A preliminary method for calculation of the seepage discharge for gravelly clayey soils having cracks was proposed. The results showed that the permeability of the gravelly clayey soils having cracks increases with the increase of the length of the cracks,but crack length and whether crack exist have no impact on self-healing of the crack and formation of the secondary filter layer. The erosion resistance strength of the gravelly clayey soil is greater than that of the common clayey soil. The hydraulic gradient for self-healing of the crack increases with the decrease in the characteristic particle size D20 of the filter. For calculation of the seepage discharge of the gravelly clayey soils with crack,the range and permeability of the loose zone around crack should be considered.
出处
《四川大学学报（工程科学版）》
CSCD
北大核心
2014年第S1期92-97,共6页
Journal of Sichuan University (Engineering Science Edition)
基金
教育部博士点基金博导类资助项目(20100181110076)
关键词
砾石土
反滤料
抗渗
裂缝
自愈
gravelly clayey soil
filter
erosion resistance
crack
self-healing
