人工示踪法测试砂土渗透流速的试验研究

流速是反映岩土体渗透特性、判断水利工程防渗效果的最直观参数;而现场岩土体中的流速却很难直接测得。自行设计室内试验装置,将食盐溶液作为示踪剂,使用电导率仪采集测试管中电导率。通过拟合得出电导率随时间的变化关系遵循指数分布,利用稀释定理计算得出测试土体中的渗透流速。将测试流速与实际流速进行对比得出,在各水利梯度下,试验中测试流速均比实际流速偏大,其误差在20%~30%。

Experimental study on seepage velocity of sand using tracer method

Velocity is the most direct reflection parameters of soil permeability characteristic and using velocity can judge the impermeable effect of hydraulic engineering, but the velocity in the field is difficult to measure directly. We design the laboratory test devices, use salt solution as the tracer, and use conductivity meter to measure the electrical conductivity in the tube. Results show that the relationship between conductivity with time follows the exponential distribution. The seepage velocity of the soil is calculated by dilution theory. The experimental velocity and real velocity were compared, in the four hydraulic gradients, the experimental velocity is bigger than the real velocity, and the error is in the 20% to 30%.