ASTM D 8121/D 8121M:2023

1.1 This test method describes approximating the shear strength of cohesive soils using a handheld (pocket) vane shear device. 1.2 The device allows for a simple and portable method for measuring the approximate undrained shear strength of saturated, fine-grained, cohesive soils. The test method can be used in the field or in the laboratory, on the ends of sample tubes, on the surface of block samples or excavations, or on the surface of other test specimens with rigid confinement. 1.3 Units- The values stated in either inch-pound units or SI units [given in brackets] are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. Tables of critical dimensions and tolerances of the described vanes are provided in separate units of inches and mm. Note 1: The original shear vane device was developed when shear strength was often reported in tons per square foot (TSF) or kilograms per square centimeter (kg/cm²) which are approximately equivalent. These units have prevailed within the industry and are adopted herein. 1.4 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 , unless superseded by this test method. 1.4.1 The procedures used to specify how data are collected, recorded, and calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user's objectives, and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this test method to consider significant digits used in analysis methods for engineering design. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

13.080.01