11/15



Cumberland and Perry Counties, PennDOT District 8-0


The U.S. Rte. 11/15 Rock Slope Safety Improvement Project is divided into two sections that are located approximately seven miles apart. The southernmost section, the Marysville Section, consists of four primary rock cuts and is located north of the U.S. Rte. 11/15 Interstate 81 interchange in East Pennsboro Township. The northern section, the Duncannon Section, consists of one rock cut and is located in Penn Township and is located approximately 0.8 miles south of the Borough of Duncannon. The purpose of the project was to increase safety for motorists by implementing a multi-faceted approach to reduce the risk of future falling rock.

AEG provided preliminary engineering, final design, and construction consultation for the rock slope protection systems that were installed at each location. AEG was responsible for investigating the existing condition of the cut slopes, providing comprehensive analysis of rockfall hazards, developing and recommending slope protection measures, and completing preliminary and final design for the recommended measures.

Our analysis included:
• Performing detailed geologic mapping of the slopes
• Analyzing existing low altitude black and white and infrared aerial photography
• Colorado Rockfall Simulation Program (CRSP) modeling
• RockPack III computer-based analysis of the rock slopes
• Identification of potential failure mechanisms
• Producing digital photographs
• Determining rock shear and compressive strength

Recognizing the unique traffic impacts involved at each project area, traffic management was critical. Road widening and road closure options were evaluated. The project team coordinated with representatives of all state, county and municipal emergency management services organizations that were affected, particularly during the Marysville Section detour. AEG provided expedited reviews of construction submittals and provided fast field response to construction matters. The effort put forth by the design team assisted the Contractor in opening the roadway nearly one month ahead of schedule.