About this Project

The Pennsylvania Turnpike Commission’s Total Reconstruction Initiative is a multi-billion-dollar effort to modernize aging sections of the Turnpike. The MP 213–226 segment in Cumberland County involves full-depth reconstruction of 13 miles of the Turnpike Mainline, including thirteen mainline bridges and thirteen overhead structures. This corridor, situated between the Blue Mountain Tunnel and the Carlisle Interchange, is part of a broader $7.5 billion capital investment plan designed to enhance safety, mobility, and long-term maintenance efficiency across the Turnpike system.

AEG provided geotechnical, survey, and Right-of-Way support during both the Preliminary and Final Design phases for the entire roadway alignment and all proposed replacement structures. Due to environmental and Right-of-Way constraints, multiple sound barriers and retaining walls were proposed and designed throughout the alignment.

The project’s geology is dominated by limestone bedrock, which presents significant challenges due to karst features, including pinnacled bedrock surfaces, sinkholes, caves, and voids. AEG evaluated remedial treatments, including over-excavation and replacement, pressure and compaction grouting, and micropile foundation designs. One critical finding was a 30-foot-deep void directly beneath a proposed bridge abutment, requiring specialized foundation recommendations to mitigate subsidence risks.

AEG managed several subsurface investigations, including boring, sampling, and testing programs for the roadway and structures. We prepared reconnaissance reports, boring layouts, Geotechnical Engineering Reports, and Structure Foundation Geotechnical Reports for bridges, culverts, sound barriers, retaining walls, and sign structures. AEG also conducted infiltration testing and geophysical studies to support the design of stormwater management.

During construction, AEG provided on-site inspection of compaction grouting operations and continued consultation to ensure geotechnical integrity and compliance with design specifications.

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