不同粘粒含量土体管涌试验研究

Research on Piping in Soils with Different Clay Particle Content

为研究粘粒对土体管涌发生发展的影响以及管涌破坏后的力学性质,配置不同粘粒含量的土样,进行室内管涌试验模拟,并取破坏后的土样进行三轴压缩试验。对各土样水力梯度-流速曲线、应力应变曲线进行分析,研究结果表明:(1)含粘粒土样的临界水力梯度和开始发生管涌破坏时的水力梯度与粘粒含量呈负相关,破坏时流速与粘粒含量呈正相关。(2)管涌后的土体,土层深度越深,土体细颗粒流失量越大,土体的强度损失越大,土体应变软化趋势越不明显。(3)粘粒含量对土体细颗粒流失起到促进作用,使得管涌后含粘粒的土样强度损失更大,粘粒含量越大,这种促进作用越明显,强度损失越大。

In order to study the influence of clay particles on the occurrence and development of pipe gushing and the mechanical properties after the failure of pipe gushing,soil samples with different clay content were arranged to simulate indoor pipe gushing test,and the damaged soil samples were taken for triaxial compression test.The results show that:(1)There is a negative correlation between the critical hydraulic gradient of clay soils and the hydraulic gradient at the beginning of piping failure and the clay content.The velocity of destruction was positively correlated with the clay content.(2)The deeper the soil layer is,the greater the loss of fine particles,the greater the strength loss,and the less obvious the strain softening trend of the soil is.(3)The clay content promotes the loss of fine particles in soil,making the strength loss of soil samples containing clay particles greater after pipe gushing.The greater the viscosity content,the more obvious the promotion effect and the greater the strength loss.