1.1 本规程提供了应用试验方法的程序 F2656/F2656M 试验方法规定的超长（即300 ft[91 m]或更大）可变宽度车辆护栏的试验标准 F2656/F2656M . 1.2 本规程提供了一个程序，以建立一个最大宽度配置，该配置相当于由试验方法定义的可变宽度屏障的无限长屏障 F2656/F2656M . 1.3 这种做法仅适用于依赖于结构上重复的内部系统的可变宽度屏障，该内部系统可能非常长，并以加强的终端终止。 1.4 仅当由于试验设施现场限制试验品的实际长度而无法或不可能安装可变宽度屏障的最大宽度试验品时，本规程才适用。 1.5 当其使用仅旨在降低供试品安装成本，而测试最大宽度安装长度是可行的时，本规程不适用。 1.6 本规程不适用于连续或其他类型的车辆护栏。 1.7 本规程应与试验方法一起使用 F2656/F2656M 建立完整可变宽度屏障的条件名称和渗透等级。此外，完整的可变宽度屏障应具有单穿透等级，该等级被确定为测试的最小和最大宽度配置的最大穿透等级，并被视为最终穿透等级。贯入度等级并非基于工程计算或判断。 1.8 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。 1.9 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。 1.10 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 试验方法 F2656/F2656M 规定应在最小和最大宽度配置下测试可变宽度屏障。如果没有对屏障进行结构修改，则允许在最大值和最小值之间进行插值（即，所有结构组件，包括支撑构件和连接件的间距，在最小和最大宽度下测试的两个屏障之间相似）。不允许在测试的最小和最大宽度配置之外进行外推。 5.2 然而，有一类障碍物，如一些依赖于结构重复内部系统的网和围栏，以及未在试验方法下明确处理的加固终端或锚具 F2656/F2656M . 在某些情况下，屏障的内部系统可能非常长，无法或不可能测试最大值- 例如，由于测试设施场地限制而导致的宽度配置。 5.3 当可变宽度壁障依赖于结构上重复的内部系统时，该系统可能非常长，并以加强的端部端子终止，则应使用本规程建立等效于无限长壁障的最大宽度配置。 5.4 本规程应与试验方法一起使用 F2656/F2656M 建立完整可变宽度屏障的条件名称和渗透等级。了解条件名称和渗透等级可以为设施周围的现场特定条件选择适当的屏障。 5.5 本惯例的使用假设: 5.5.1 除仪表终端外，结构重复的内部系统的构造和安装方式代表拟议的实际服务安装； 5.5.2 除仪表终端外，结构重复的内部系统符合供应商规范和图纸； 5.5.3 应使用用于最小宽度配置测试的加固终端终止结构重复内部系统的实际服务安装；和 5.5.4 用于最大宽度配置的仪表终端应仅提供轴向负载阻力。

1.1 This practice provides a procedure for applying Test Method F2656/F2656M test criteria to an exceptionally long (that is, 300 ft [91 m] or greater) variable-width vehicle barrier as defined by Test Method F2656/F2656M . 1.2 This practice provides a procedure to establish a maximum-width configuration that is equivalent to an infinitely long barrier for a variable-width barrier as defined by Test Method F2656/F2656M . 1.3 This practice applies only to variable-width barriers that are dependent on both a structurally repetitive interior system that could be exceptionally long and terminated with strengthened end terminals. 1.4 This practice applies only when it is impractical or impossible to install the maximum-width test article of a variable-width barrier because the test facility site constraints limit the practical length of the test article. 1.5 This practice does not apply when its use is employed solely with the intent of reducing the test article installation cost when it is practical to test the maximum-width installation length. 1.6 This practice does not apply to continuous or other types of vehicle barriers. 1.7 This practice shall be used with Test Method F2656/F2656M to establish a condition designation and penetration rating for the complete variable-width barrier. Further, the complete variable-width barrier shall receive a single penetration rating that is determined as the maximum penetration rating for both the minimum- and maximum-width configurations tested, and is taken to be the final penetration rating. The penetration rating is not based on engineering calculation or judgment. 1.8 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. 1.9 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. 1.10 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 Test Method F2656/F2656M states that variable-width barriers shall be tested in minimum- and maximum-width configurations. Interpolations between maximum and minimums are allowed if there are no structural modifications made to the barrier (that is, all structural components, including spacing of support members and connections, are similar between the two barriers tested at minimum and maximum widths). Extrapolation outside of the tested minimum- and maximum-width configurations is not allowed. 5.2 However, there is a class of barriers such as some nets and fences that rely on a structurally repetitive interior system and strengthened end terminals or anchorages that are not explicitly treated under Test Method F2656/F2656M . There are situations where the interior system of the barrier could be exceptionally long and it is impractical or impossible to test the maximum-width configuration due to test facility site constraints, as an example. 5.3 When a variable-width barrier is dependent on a structurally repetitive interior system that could be exceptionally long and terminated with strengthened end terminals, this practice shall be used to establish the maximum-width configuration that is equivalent to an infinitely long barrier. 5.4 This practice shall be used with Test Method F2656/F2656M to establish a condition designation and penetration rating for the complete variable-width barrier. Knowing the condition designation and penetration rating provides the ability to select an appropriate barrier for site-specific conditions around a facility. 5.5 Use of this practice assumes: 5.5.1 Except for the instrumented end terminations, the structurally repetitive interior system is constructed and installed in a manner that represents the proposed actual service installation; 5.5.2 Except for the instrumented end terminations, the structurally repetitive interior system conforms to supplier specifications and drawings; 5.5.3 The actual service installation of the structurally repetitive interior system shall be terminated using the strengthened end terminals used for the minimum-width configuration test; and 5.5.4 The instrumented end terminations used for the maximum-width configuration shall provide axial load resistance only.