Dilworth Plaza, City Hall Renovation, Philadelphia, Pennsylvania

Home 5 Selected Projects 5 Commercial 5 Dilworth Plaza

Overview: Philadelphias City Hall is a National Historic Landmark and the world’s tallest masonry building. Dilworth Plaza’s west side underwent a $50 million renovation to transform this historic civic space into the cultural, social, and commercial center it was intended to be. GeoStructures provided multiple aspects of a design role for the project. 

The project involved reconfiguring the plaza level, as well as adding multiple sitting areas, a programmable and interactive fountain, a cafe, and an outdoor venue that can convert to an outdoor skating rink during the winter months.

GeoStructures’ design role in this project involved a detailed geotechnical investigation, an assessment of existing foundations, foundation design requirements for the planned renovation, and consideration of conflicts between existing and proposed structural supports.

To accomplish the reconstruction, many of the new foundation supports needed to penetrate a labyrinth of two or even three underground subway tunnel levels, as well as pedestrian and utility tunnels. During construction, GeoStructures was also responsible for performing periodic inspections to ensure the foundation conditions were consistent with the subsurface characterization and design assumptions.


Connect with us.

Providing state-of-the-art geotechnical engineering services with an unwavering commitment to excellence and innovation.

Percolation and Permeability In-Situ Testing 

Drilling Services and Subsurface Investigations

Foundation Investigation and Design

Highway and Bridge Geotechniques

Support of Excavation and Underpinning

Soil-Structure Interaction Analysis and Modeling

Soil Dynamics & Site-Specific Response Spectra

Vibration Monitoring and Analyses

Forensic Evaluations

Slope and Retaining Wall Evaluation and Design

Lime and Cement Stabilization

Mine Subsidence Analysis and Remediation

Sinkhole Evaluation and Remediation

Soil Improvement Techniques

Dam Analysis and Rehabilitation

Environmental Services

Landfills, Ponds, and Lagoons

Pavement Design and Rehabilitation

Construction Inspection and Materials Testing

Geotechnical Laboratory Testing

Concrete and Cement Testing

Petrographic Analysis

Instrumentation and Special Testing

Asphalt Testing

View All Services >

3-D Dynamic Finite Element Analysis



Institutional & Educational


Industrial, Pharmaceutical, & Gene Therapy

Landfill Expansion Design


Research & Forensics


Water & Wastewater

View All Selected Projects >

Who We Are 

Who We Are

Meet Our Team

Contact Us 

Pay Invoice

Contact Us