About this Project

The US 11/15 Rock Slope Safety Improvement Project was designed to enhance motorist safety by mitigating the risk of falling rocks along a critical corridor in central Pennsylvania. The project was divided into two distinct sections, approximately seven miles apart. The southernmost portion, known as the Marysville Section, featured four primary rock cuts and was located just north of the US 11/15 and Interstate 81 interchange in East Pennsboro Township. The Duncannon Section, situated in Penn Township approximately 0.8 miles south of the Borough of Duncannon, included one major rock cut. A multi-faceted approach was implemented to reduce rockfall hazards and improve long-term slope stability.

AEG served as the Prime Consultant for this project-specific open-end contract, providing comprehensive engineering services from preliminary investigation through final design and construction consultation. AEG’s scope included detailed geologic mapping of the slopes, analysis of historical aerial photography, and advanced modeling using the Colorado Rockfall Simulation Program (CRSP) and RockPack III. The team identified potential failure mechanisms, assessed rock shear and compressive strength, and produced digital documentation to support design decisions. These efforts culminated in the development and implementation of tailored slope protection systems for each location.

Recognizing the unique traffic impacts associated with each section, AEG evaluated road widening and closure options to minimize disruption. The project team coordinated closely with state, county, and municipal emergency management services, particularly during the Marysville Section detour. AEG’s expedited reviews of construction submittals and rapid field responses played a critical role in maintaining project momentum. These efforts contributed to the Contractor reopening the roadway nearly one month ahead of schedule.

The project was honored with the ASHE Northeast Region’s Project of the Year award in 2018, a testament to the collaborative effort and technical excellence demonstrated throughout its execution. AEG’s leadership and responsiveness ensured that safety improvements were delivered efficiently and effectively, reinforcing the firm’s reputation for high-quality geotechnical and civil engineering services on complex transportation projects.

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