ISO 17892-6:2017规定了通过落锥法对细粒土原状和重塑试样进行不排水强度指数测试的方法。 ISO 17892-6:2017适用于岩土工程勘察范围内土壤试样不排水抗剪强度的实验室估算。 在落锥试验中，允许锥体尖端朝着土壤样本落下，并测量锥体在土壤中的穿透力。贯入度值用于估算不排水抗剪强度。落锥试验在试样中产生复杂的剪切，不代表垂直三轴压缩或水平剪切试验。 然而，该指数试验可能与实验室通过其他试验方法确定的不排水抗剪强度的某些估计值相关。 由于试验是在小型实验室样本上进行的，因此结果可能与较大样本上的实验室试验不一致。此外，试样可能无法完全代表现场自然状态下的土壤；例如，试样可能不会在大于试样尺寸的间距处原位出现裂缝。 因此，基于上述原因，该试验可被视为不排水抗剪强度的估算，而不是不排水抗剪强度的真实测量。 重塑抗剪强度与原状抗剪强度之比可用于估算土样的敏感性。 剪切强度的时间相关测量可用于评估重塑土样的触变恢复强度。 注:根据EN 1997，本文件满足岩土工程勘察和测试用土壤强度指数测试的要求？1和EN 1997？2.

ISO 17892-6:2017 specifies a method of undrained strength index testing of both undisturbed and remoulded specimens of fine grained soils by the fall cone method. ISO 17892-6:2017 is applicable to the laboratory estimation of undrained shear strength of a soil test specimen within the scope of geotechnical investigations. In the fall cone test, a cone is allowed to fall with its tip towards a soil specimen, and the resulting penetration of the cone into the soil is measured. The penetration values are used to estimate the undrained shear strength. The fall cone test produces a complex shear in the test specimen, and does not represent either a vertical triaxial compression or a horizontal shear test. However, this index test may be correlated to some estimate of undrained shear strength determined in the laboratory by other test methods. As the test is performed on a small laboratory specimen, the result may not agree with laboratory tests on larger specimens. In addition, the test specimen may not be fully representative of the soil in its natural state in the field; for example, the test specimen may not have fissures present in situ at a larger spacing than the specimen size. Therefore, for the above reasons, the test can be regarded as an estimation of undrained shear strength, rather than a true measurement of it. The ratio of the remoulded shear strength to the undisturbed shear strength may be used to estimate the sensitivity of a soil specimen. Time-dependent measurement of the shear strength may be used to assess the thixotropic regain of strength of a remoulded soil specimen. NOTE This document fulfils the requirements of the strength index testing of soils for geotechnical investigation and testing in accordance with EN 1997?1 and EN 1997?2.