Case Study: QC Failures in Earthwork and Embankment on I-15 Expansion (Utah, 2018)

Project Overview
• Name: Interstate 15 Widening and Reconstruction
• Location: Salt Lake City, Utah
• Year: 2018
• Project Size: $320 million
• Scope: Earthwork, embankment construction, and pavement widening
• Lead Agencies/Contractors: Utah Department of Transportation (UDOT) /

Category of the Issue, Problem, or Challenge
• Quality Control
• Geotechnical
• Project Delay

Summary of the Issue, Problem, or Challenge
Poor compaction and inadequate moisture control in embankment fill led to settlement issues, triggering rework and delays during construction.

Root Cause Analysis

• Insufficient soil compaction testing frequency and inconsistent moisture content monitoring.
• Lack of real-time feedback to earthwork crews on compaction deficiencies.
• Poorly documented QC procedures and absence of corrective action protocols.
• Inadequate training of earthwork operators on compaction best practices.

Impacts Due to the Issue, Problem, or Challenge

• Delay of 3 months due to re-compaction and additional soil stabilization.
• Increased project costs from rework and extended equipment use.
• Potential long-term settlement risks if uncorrected.

Corrective Actions Taken

1. Enhanced compaction testing protocols with higher frequency and stricter thresholds.
2. Implemented real-time data collection and communication systems for field crews.
3. Developed corrective action procedures for immediate issue resolution.
4. Conducted training sessions for equipment operators and QC inspectors.

Lessons Learned

• Frequent and accurate compaction testing is critical to embankment stability.
• Real-time communication improves field responsiveness.
• Documented QC and corrective actions prevent repeated issues.

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

• Are compaction tests conducted frequently and documented?
• Is there real-time communication of test results to field crews?
• Are corrective actions clearly defined and enforced?