Saturation of soils is a prerequisite in many laboratory tests involving consolidation, permeability and stress–strain behaviour. The saturation process is usually time consuming, particularly in clay-rich soils, and this can incur substantial cost and potential delays in reporting findings. The saturation of samples is assessed using the well-established Skempton's pore water pressure parameter B. In a situation where the soil is fully saturated, the B-value is approximately one. It is often the case that fine soil samples extracted from the ground, particularly those from below the water table, remain saturated. However, current testing protocols require evidence to verify a complete saturation prior to subsequent laboratory investigations. This paper reports experimental results exploring the hypothesis that, if the sample is ‘perceived’ to be saturated, then further saturation procedures may not be necessary to obtain reliable geotechnical parameters. Laboratory investigations were conducted on three different clays (kaolin clay, Belfast clay and Oxford clay) in a testing chamber instrumented with a high-capacity tensiometer. The confining pressures were applied in a ramped fashion under undrained conditions. The response of the tensiometer confirmed that the samples were saturated from the very beginning of the loading process, as implied by the B-value being close to one. Further supplementary investigations were carried out to assess the Skempton's pore water pressure parameter A and the stress–strain behaviour of the soils. The combined finding provides further evidence to suggest that the saturation process as suggested in standards may not be necessary for fine-grained soils to establish reliable geotechnical design parameters.

中文翻译：

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使用大容量张力计评估Skempton的孔隙水压力参数B和A

在涉及固结，渗透性和应力应变行为的许多实验室测试中，土壤饱和是先决条件。饱和过程通常是耗时的，尤其是在粘土丰富的土壤中，这可能会导致实质性的成本以及报告结果的潜在延迟。使用公认的Skempton孔隙水压力参数B评估样品的饱和度。在土壤完全饱和的情况下，B-值约为1。通常情况下，从地面提取的细土壤样品（尤其是从地下水位以下提取的样品）保持饱和。但是，当前的测试方案需要证据来证明在随后的实验室研究之前已完全饱和。本文报告了探索以下假设的实验结果：如果“感知”到样品已饱和，则可能不需要进一步的饱和程序即可获得可靠的岩土参数。在装有高容量张力计的测试室内，对三种不同的粘土（高岭土，贝尔法斯特粘土和牛津粘土）进行了实验室研究。在不排水条件下以渐进方式施加围压。B值接近1。进行了进一步的补充研究，以评估Skempton的孔隙水压力参数A和土壤的应力应变行为。结合的发现提供了进一步的证据，表明标准中建议的饱和过程对于细粒土壤建立可靠的岩土工程设计参数可能不是必需的。