Structures Detailing Manual | July 2007
11 - Slope Protection |

# 11 - Slope Protection

## 11.1 General

This chapter provides bridge designer with the necessary information to develop plan details for appropriate slope protection. See SDMEx3, SDMEx-4 and SDMEx-5. In most cases the standard details depicted for slope protection, with minor modifications will be suitable. In some cases, typically in tidal areas or when severe scour conditions exist, special designs and details may be required.

## 11.2 Responsibility

A. Determine Begin and End Bridge stations and select the appropriate type, slope rate and extent of slope protection for highway and railroad grade separations.

B. For water crossings, consult the Drainage Engineer for minimum Begin and End Bridge stations and for type, slope rate and minimum extent of slope protection. Discuss any alteration to the recommended end location and protection design with the Drainage Engineer.

## 11.3 Grade Separations

A. For grade separation bridges, design slope pavement on 1:2 slopes with provisions to extend erosion protection to a minimum of four feet outside the superstructure coping. Extend slope protection in the median of dual bridges the entire width between bridges when the median width (distance between copings) is forty feet or less at rural locations or fifty feet or less at urban locations.

B. To protect railroad track embankments, use sand-cement riprap instead of slope pavement.

## 11.4 Water Crossings

A. The Drainage (Hydraulic) Engineer will determine the design and extent of the slope protection in accordance with the FDOT Drainage Manual and other applicable guidelines such as HEC-18. The slope protection for spill-through abutments (End Bents) adjacent to water will usually be rubble riprap. Sand-cement riprap is usually limited to bridges over streams or canals with extremely low, non-erodible flow velocities under all flood conditions. A 1:2 slope is the steepest desirable slope rate.

B. Bulkhead abutments can be protected by sheet piling or precast panels with toe protection provided by rubble riprap. Rubble riprap might also be recommended above the bulkhead or at its ends. Never design the protection to be extended less than four feet outside the superstructure coping.

C. Extend the slope protection in the median between dual bridges to include:

1.) The entire median width for rural area bridges with a separated median width of forty feet or less.

2.) The entire median width for urban area bridges with a separated median width of fifty feet or less.

3.) The entire width for urban area bridges inaccessible due to physical barriers or when access is severely limited due to design features or vehicular movement that will impede the ability to maintain the facility.