Heifangtai is one of the typical loess platforms in Gansu province.The platform surface has been largely irrigated over the past forty years.The underground water level upraised and many landslides occurred.The frequent loess landslides have seriously threatened the local development.This paper carries out the double rings infiltration tests,varying-head infiltration test for the disturbed samples and varying-head infiltration test for the remolded samples.It analyzes the characteristics among the three tests.It uses the geophysical prospecting to verify the test results.The following conclusions are made:(1) The permeability coefficient of unsaturated loess tested by the three kinds of tests are linearly decreases with the increase of dry density;(2) Under the same conditions the permeability coefficient tested by the double rings infiltration tests is the largest.The remolded samples' permeability coefficient is the minimum.The differences among the results from the three types of permeability coefficient tests decrease with the increase of dry density;(3)The permeability coefficient tested by the double rings infiltration tests is most close to the in situ loess permeability according to the high-density electrical method.%位于黄土高原的甘肃黑方台由于常年的农业灌溉导致地下水位抬升诱发了大量黄土滑坡,造成很大损失,研究灌溉水在非饱和黄土中的渗透特性对该地区滑坡的防控具科学指导意义.本论文通过现场双环试验、原状样室内变水头渗透试验、重塑样室内变水头渗透试验,对黑方台黄土的渗透特性进行对比分析,最后通过高密度电法及探井测量进行对比验证.得出以下结论:(1)3类试验方案中非饱和黄土的渗透系数均随着干密度的增大呈线性减小;(2)同一条件下的黄土,双环试验所得渗透系数最大,原状样次之,重塑样最小;干密度越大,3类渗透系数差异性越小;(3)高密度电法验证与双环试验结果最接近,探井验证得出高密度电法在黄土地区的适用性.
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