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此前,已有学者提出,可以利用三轴剪切试验仪来测定低渗透性土的渗透性能。作者就该法有关试验参数对测求渗透系数的影响进行了研究。研究结果表明,用于这种渗透试验的柱形试样,其直径不应小于71.1mm(2.8ft),其高度和直径之比宜在0.5到1.0之间。试验渗透液一般可采用1升中溶有1克七水合硫酸镁的脱气蒸馏水。试验应控制在一定的水力梯度下,使试样渗出端的外加有效应力不致高于土料的先前固结压力。研究还发现,只要细心处理,可使试件修切扰动的影响减至最小。
Earlier, some scholars have suggested that a triaxial shear tester can be used to determine the permeability of low-permeability soils. The authors studied the influence of the test parameters on the permeability coefficient measured. The results of the study indicate that the cylindrical specimen used for this type of penetration test should have a diameter of not less than 71.1 mm (2.8 ft) and a height to diameter ratio of 0.5 to 1.0. The test permeate may generally be one liter of degassed distilled water containing 1 gram of magnesium sulfate heptahydrate dissolved therein. The test should be controlled under a certain hydraulic gradient so that the applied effective stress of the exuded end of the sample is not higher than the previous consolidation pressure of the soil. The study also found that as long as careful handling is performed, the effect of trimming disturbance of the test piece can be minimized.