1.1 本试验方法涵盖了在不同法向压缩应力和恒定水头下测定土工合成材料制造平面内单位宽度流速的程序。该试验主要用于指数试验，但也可用于用户选择水力梯度和试样接触面以模拟预期现场条件时的性能试验。 1.2 本试验方法仅限于允许连续平面内流动路径平行于预期流动方向的土工合成材料。 1.3 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值不一定是精确的等价物；因此，为确保符合本标准，每个系统应独立使用，且两个系统的值不得组合。 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 本试验方法旨在作为指数试验或性能试验，用于确定和比较一种或几种备选土工合成材料在特定条件下的单位宽度流速。 5.2 本试验方法可用作土工合成材料商业装运验收试验的指标试验，但由于本试验方法的实验室间精度信息不完整，建议谨慎。按照中的指示进行比较测试 5.2.1 可能是可取的。 5.2.1 如果在使用本测试方法进行商业装运验收测试时，由于报告的测试结果不同而产生争议，买方和供应商应首先确认测试是使用可比较的测试参数进行的，包括样品调节、法向应力、固定期、水力梯度、测试水温等。，然后进行比较测试，以确定他们的实验室之间是否存在统计偏差。建议为调查偏差提供称职的统计协助。 作为最低要求，双方应采取一组尽可能同质的试样，这些试样由大量相关类型的材料制成。然后，应将试样以相同数量随机分配给每个实验室进行测试。两个实验室的平均结果应使用学生的 t -测试未配对数据和双方在测试开始前选择的可接受概率水平。如果发现偏差，必须找到并纠正其原因，或者买方和供应商必须同意根据已知偏差解释未来的测试结果。

1.1 This test method covers the procedure for determining the flow rate per unit width within the manufactured plane of geosynthetics under varying normal compressive stresses and a constant head. The test is intended primarily as an index test but can be used also as a performance test when the hydraulic gradients and specimen contact surfaces are selected by the user to model anticipated field conditions. 1.2 This test method is limited to geosynthetics that allow continuous in-plane flow paths to occur parallel to the intended direction of flow. 1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.4 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. 1.5 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. ====== Significance And Use ====== 5.1 This test method is intended either as an index test or as a performance test used to determine and compare the flow rate per unit width of one or several candidate geosynthetics under specific conditions. 5.2 This test method may be used as an index test for acceptance testing of commercial shipments of geosynthetics, but caution is advised since information on between-laboratory precision of this test method is incomplete. Comparative tests as directed in 5.2.1 may be advisable. 5.2.1 In case of a dispute arising from differences in reported test results when using this test method for acceptance testing of commercial shipments, the purchaser and the supplier should first confirm that the tests were conducted using comparable test parameters including specimen conditioning, normal stress, seating period, hydraulic gradient, test water temperature, etc., then conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statistical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens that are as homogenous as possible and that are formed from a lot of the material of the type in question. The test specimens should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using the Student's t -test for unpaired data and an acceptable probability level chosen by the two parties before the testing is begun. If bias is found, either its cause must be found and corrected or the purchaser and supplier must agree to interpret future test results in light of the known bias.