Case Study: Owner-Mandated Redesign Halts Retaining Wall Construction in Pennsylvania (2021)

Project Overview
• Name: I-76 Slope Stabilization & Retaining Walls
• Location: Pittsburgh, Pennsylvania
• Year: 2021
• Project Size: $145 million
• Scope: Roadside slope stabilization and retaining wall reconstruction
• Lead Agencies/Contractors: Pennsylvania DOT (Owner) /

Category of the Issue, Problem, or Challenge
• Contract Owner
• Mid-Construction Design Changes

Summary of the Issue, Problem, or Challenge
PennDOT issued a mid-construction directive to redesign 2 retaining walls based on new geotechnical studies, pausing fieldwork for 10 weeks while engineering and permits were revised.

Root Cause Analysis

• Owner authorized early construction start before full geotechnical review.
• Site conditions revealed wall foundation risks not accounted for in original design.
• Design changes required revised calculations, drawings, and re-permitting.

Impacts Due to the Issue, Problem, or Challenge

• Construction halted for redesign, delaying adjacent earthworks.
• Cost increase of $7.3 million due to new foundation materials.
• Contractual dispute over cost liability for owner-initiated changes.

Corrective Actions Taken

1. PennDOT restructured design review workflows to delay NTP until final investigations.
2. Geotechnical peer reviews were added prior to releasing construction packages.
3. Contingency fund for owner-driven changes was added to future contracts.

Lessons Learned

• Owners must complete all critical investigations before issuing NTP.
• Midstream design changes impact schedule, cost, and contractor trust.
• Shared risk provisions help mitigate redesign disruption.

Audit & Prevention: Project Control Questions to Ask on Future Projects to Help Control the Situation

• Are site conditions and design packages fully validated pre-construction?
• Does the contract define liability for owner-initiated design revisions?
• Is there a pre-established process for rapid redesign and approval?