本文件描述了一种指数测试，用于确定土工合成材料在暴露于半球形物体冲击载荷的硬表面上的保护效率。 指数测试测量了位于土工合成材料和刚性支撑之间的薄铅板的厚度变化。 它也被用作性能测试，通过使用真实的刚性表面来保护和真实的土工合成材料序列。 该试验适用于所有孔径小于15mm（最大尺寸）的土工合成材料。

This document describes an index test for the determination of the protection efficiency of a geosynthetic on a hard surface, exposed to the impact load of a hemispherical object. The index test measures the change in thickness of a thin lead plate lying between the geosynthetic and a rigid support. It is also used as a performance test, by using the real rigid surface to protect and the real sequence of geosynthetics. The test is applicable to all geosynthetics with apertures smaller than 15 mm (maximum size).