摘要
管涌对堤防与大坝的危害严重而常见,但对管涌发生后期细颗粒涌出以及地基土体渗透性非均匀发展的研究不够深入。由于管涌发生发展的随机性和复杂性,通过自行设计试验装置,在特定试验条件下,利用3组级配不同孔隙比变化的12种试样,从测压管水头、流量、渗透系数、细颗粒变化趋势、累计涌砂量等方面进行对比分析,研究渗透系数、孔隙比、试样内部细颗粒运动趋势和剩余细颗粒含量等的变化规律;结合理论计算,揭示试样内部细颗粒运动趋势、剩余细颗粒含量以及渗透系数非均匀变化的相关关系;利用渗透系数与孔隙率的关系,推导出上游水头固定下的累计涌砂量随时间变化的理论公式。
It is well known that the piping effect has serious hazards to embankments and dams, but the study on the emission of fine particles of soil and on the development of non-uniform penetration of soil foundation after the piping effect is not deep enough. Since the development of piping effect is random and complex, by means of a self-designed equipment, under particular testing conditions, 12 samples with three different pore size distributions are used to make a comparative analysis from the aspects such as piezometric head, flow, coefficient of permeability, trend of fine particles and cumulative amount of sand. Furthermore the coefficient of permeability, void ratio, movement trend of the fine particles in samples and the change law of content of the remaining fine particles are studied. Combined with theoretical calculations, the movement trend of the fine particles in the samples, the non-uniform correlation between the content of the remaining fine particles and the permeability change can be revealed. By using the relationship between permeability and porosity, a theoretical formula can be deduced from the changing amount of accumulated sand over time under the fixed upper head.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2012年第8期1432-1439,共8页
Chinese Journal of Geotechnical Engineering
基金
国家重点基础研究发展规划(973计划)项目(2007CB714102)
河海大学中央高校基本科研业务费项目(2009B00714)
关键词
管涌
无黏性土
涌砂量
渗透系数
piping
cohesionless soils
amount of accumulated sand
coefficient of permeability
