1.1 本试验方法包括使用涵洞作为计量装置计算明渠或溪流中的水流量（体积流量）。一般来说，本试验方法不适用于带下降式进水口的涵洞，仅在有限程度上适用于带锥形进水口的涵洞。ISO 748和ISO 1070中提供了与本试验方法相关的信息。 1.2 如果使用高水位线，该试验方法产生洪水事件的流量。然而，对于位于涵洞引道段的水位计，可以手动或使用计算机程序获得完整的水位流量关系。 1.3 以英寸-磅为单位的数值应视为标准值。 括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。 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 当无法使用某种类型的流速仪直接测量流量以获得速度和测深设备以确定横截面时，该试验方法对于确定流量特别有用。见测试方法 D3858 . 5.2 即使在最好的情况下，可用的人员也无法覆盖重大洪水期间的所有关注点。如果水位上升或下降非常快，如果流冰或碎屑干扰深度或速度测量，或者如果冲积河道的横截面正在显著冲刷或填充，工程师或技术人员无法始终通过直接方法获得可靠的结果。 5.3 在洪水条件下，通道可能被堵塞，索道和桥梁可能被冲毁，而对洪水的了解往往来得太晚。因此，需要某种类型的间接测量。使用涵洞确定流量是一种常用做法。

1.1 This test method covers the computation of discharge (the volume rate of flow) of water in open channels or streams using culverts as metering devices. In general, this test method does not apply to culverts with drop inlets, and applies only to a limited degree to culverts with tapered inlets. Information related to this test method can be found in ISO 748 and ISO 1070. 1.2 This test method produces the discharge for a flood event if high-water marks are used. However, a complete stage-discharge relation may be obtained, either manually or by using a computer program, for a gauge located at the approach section to a culvert. 1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 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 particularly useful to determine the discharge when it cannot be measured directly with some type of current meter to obtain velocities and sounding equipment to determine the cross section. See Test Method D3858 . 5.2 Even under the best of conditions, the personnel available cannot cover all points of interest during a major flood. The engineer or technician cannot always obtain reliable results by direct methods if the stage is rising or falling very rapidly, if flowing ice or debris interferes with depth or velocity measurements, or if the cross section of an alluvial channel is scouring or filling significantly. 5.3 Under flood conditions, access roads may be blocked, cableways and bridges may be washed out, and knowledge of the flood frequently comes too late. Therefore, some type of indirect measurement is necessary. The use of culverts to determine discharges is a commonly used practice.