CAJ | 학술논문

渗透变形是砂砾石土地基及堤防结构破坏的常见形式之一。影响砂砾石土渗透变形的因素很多，其中颗粒级配及应力状态是最重要的两个因素。为研究土体应力状态大小对砂砾石土渗透变形临界水力梯度的影响，通过研制大直径渗透变形仪加载系统，完成了侧限条件下砂砾石土在0.1、0.3、0.6、0.9MPa铅直应力作用下的渗透变形试验。试验成果及理论研究都表明砂砾石土渗透变形临界水力梯度随着应力状态的提高而加大，两者之间近似呈线性增加关系。渗透变形过程中，砂砾石土产生的渗透挤密和潜蚀现象是引起渗透系数演化的内在原因；基于渗透系数先减小再增大的变化规律，提出了应用渗透系数变化过程线确定渗透变形临界水力梯度的新途径。
삼투변형시사력석토지기급제방결구파배적상견형식지일。영향사력석토삼투변형적인소흔다，기중과립급배급응력상태시최중요적량개인소。위연구토체응력상태대소대사력석토삼투변형림계수력제도적영향，통과연제대직경삼투변형의가재계통，완성료측한조건하사력석토재0.1、0.3、0.6、0.9MPa연직응력작용하적삼투변형시험。시험성과급이론연구도표명사력석토삼투변형림계수력제도수착응력상태적제고이가대，량자지간근사정선성증가관계。삼투변형과정중，사력석토산생적삼투제밀화잠식현상시인기삼투계수연화적내재원인；기우삼투계수선감소재증대적변화규률，제출료응용삼투계수변화과정선학정삼투변형림계수력제도적신도경。
Seepage failure is one of the destructive types of levee structure and foundation in sandy-gravel soil stratum. Seepage failure of sandy-gravel soil is influenced by many factors. Especially,the grain compo-sition and the stress state are the most important factors. To explore the influence of stress state in the soil mass on the critical hydraulic gradient of seepage failure, a loading system for seepage failure experiment has been developed. The seepage failure experiments of sandy-gravel soil samples, which are under lateral confining condition, are accomplished by exerting 0.1, 0.3, 0.6 and 0.9MPa vertical stress on the top of the sample. Both the experimental and theoretical research results indicate that the critical hydraulic gradi-ent of sandy-gravel soil increases with the increment of stress. There exists a linear relationship between the critical hydraulic gradient and stress. During the whole seepage failure process, the seepage clogging and suffusion are the intrinsic reasons to cause the evolution of coefficient of permeability. Based on the variation law of coefficient of permeability, a new approach to determine the critical hydraulic gradient is proposed through the variation process lines obtained from seepage failure experiment.