Full-depth reconstruction of 13 miles of the Pennsylvania Turnpike Mainline
- Owner: Pennsylvania Turnpike Commission
- Location: Cumberland County, PA
About this Project
This project consisted of the Turnpike roadway reconstruction between Mileposts 213. and 220, including thirteen mainline structures and thirteen overhead structures. AEG provided geotechnical, survey, and Right-of-Way support during the Preliminary and Final Design phases for the entire roadway alignment and all the proposed replacement structures. Due to Right-of-Way and environmental constraints, multiple sound barriers and retaining walls were proposed and designed throughout the alignment.
The geology of nearly the entire project consisted of limestone bedrock formations. The calcareous bedrock of the region coincided with karst features, including pinnacled bedrock surfaces, sinkholes, caves and voids, and other solution features. These surface and subsurface features required evaluating remedial treatments such as over-excavation and replacement, pressure and compaction grouting, and micropile foundation designs.
Critical aspects of this project included the presence of karst conditions beneath at least three proposed bridge structures. A 30-foot-deep void was encountered directly beneath a proposed bridge abutment. AEG provided recommendations to remediate the karst conditions for foundation designs to minimize the risk of potential subsidence throughout the design life of the structures.
AEG provided on-site inspection of compaction grouting operations along with additional construction-phase consultation.
AEG managed several subsurface investigations, including the roadway and structures’ boring, sampling, and testing program. AEG prepared reconnaissance reports and boring layouts for the roadway alignment and proposed structures along with Geotechnical Engineering Reports and Structure Foundation Geotechnical Reports for proposed bridges, culverts, sound barriers, retaining walls, and sign structures. AEG was also involved with the Infiltration Testing program and geophysical studies related to stormwater management.