FLH PDDM Chapter 9 - Eastern Federal Lands Highway Division

9.4.A. Geometric Design. (continued)h. Serrated Slopes. Serrated slopes are a series of small steps in soft rippable rock cuts having sloperatios between 1.3:1 and 1:2. The steps allow weathering and decomposing rock to accumulate to providea growing medium for plants. The flat steps also retain moisture for use by the growing plants. Whenusing serrated slopes, take into consideration local environmental conditions, soil, and plant growthpotential. Figure 9-13 shows a typical section of a serrated slope.Include a drawing in the plans showing step tread and rise dimensions. Generally, the step rise varies from0.5 meters for easily ripped rock to 1.5 meters for harder rippable rock. The step tread width is equal tothe rise multiplied by the cut slope ratio.9 - 48