ISO 17892-6:2017规定了通过秋锥法对细粒土壤的未受干扰和重塑的样品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剪切强度的实验室估算。 在秋季锥体试验中，允许锥体与其尖端朝向土壤样品下落，并且测量所得到的锥体渗透到土壤中。穿透值用于估计不排水的剪切强度。秋季锥测试在试样中产生复杂剪切，并不代表垂直三轴压缩或水平剪切试验。然而，该指标测试可能与实验室通过其他测试方法确定的一些不排水剪切强度的估计相关。 由于在小型实验室样本上进行了测试，结果可能与较大样本的实验室测试不一致。此外，试样可能不能完全代表现场天然状态的土壤;例如，试样可能没有原位存在比样品尺寸更大的间隙的裂缝。 因此，由于上述原因，可以将该试验视为对不排水剪切强度的估计

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.