Case Study: Racine Road Stabilization Project

Project Overview

• Project: Deep Soil Injection (DSI) for roadbed stabilization around an HDPE culvert along 1st Range Road in Racine, Québec.

• Location: Intersection of Courtemanche Road and 1st Range Road, Racine, Québec

• Client: Municipality of Racine

• Engineering Partner: Gestimaction Inc.

• Installer: Purlift Inc.

Challenge

The Municipality of Racine was experiencing recurring annual settlement and road deformation near an HDPE culvert located along 1st Range Road. Each spring thaw caused visible depressions and surface cracking on both sides of the culvert. Over time, this freeze–thaw cycle compromised the stability of the surrounding road structure.

A site inspection conducted by Gestimaction’s engineer, representatives from PURLIFT®, and the municipal road inspector revealed that although the culvert remained structurally sound, the surrounding embankment and sub-base materials had deteriorated. Heterogeneous fill, voids, and poor compaction were identified as the main contributors to recurring settlement. A conventional reconstruction would have required full excavation and replacement of the culvert foundation — a costly and disruptive process.

Findings

No geotechnical study was available for the site. Based on regional soil characteristics and local experience, the subgrade was assumed to consist of mixed sand, silt, gravel, and clay materials with variable moisture content. Preliminary field testing using a Dynamic Cone Penetrometer (DCP) confirmed heterogeneity and moderate-quality backfill materials, with penetration refusal occurring around 0.6 m deep — consistent with voided or blocky zones causing differential settlement during freeze–thaw cycles.

Infrastructure composition was estimated as follows:

• Upper base: MG-20b crushed stone (~100 mm thick)

• Subbase: MG-112 crushed stone (~300 mm thick)

• Natural subgrade: heterogeneous fill with sand, gravel, and silt

Solution: Deep Soil Injection (DSI)

Given the conditions, Gestimaction and PURLIFT® implemented Deep Soil Injection using a fast HydroFoam — a hydrophobic, 4 lb/ft³ (≈64 kg/m³) structural polyurethane resin ideal for wet environments and roadbed reinforcement. The goal was to compact loose soils, fill voids, and stabilize the foundation around the culvert while minimizing disturbance to the road surface.

Process:

1. Injection Layout:   The project covered approximately 12 m of roadway, with an 8 m road width and 1.8 m shoulders on each side. Injection depths ranged from 1.2 m near the culvert crown to 1.6 m at the outer zones, simulating a 1V:5H slope transition required for 50 km/h rural roads. Injection spacing averaged 1.0–1.5 m.

2. Material Characteristics:   The HydroFoam polyurethane expands up to 18× its liquid volume, with a compressive strength of 90–100 psi (≈620–690 kPa) and hydrophobic properties ensuring long-term dimensional stability even in saturated soils.

3. Execution:   Work was performed on May 17, 2023, under cold, cloudy conditions (2°C with light snow). The crew drilled and injected progressively deeper near the culvert, ensuring full lateral coverage. The foam expansion was monitored in real time, with surface heaving and fissuring confirming proper densification.

Results

The Racine Road Stabilization Project was successfully completed in one day without traffic disruption or excavation. The injected polyurethane stabilized the roadbed, reinforced the culvert surroundings, and eliminated voids contributing to seasonal settlement.

In addition to subgrade stabilization, the asphalt surface was lifted and levelled, restoring proper road profile and eliminating depressions caused by repeated freeze–thaw cycles.

Key outcomes include:

• Full stabilization of approximately 12 m of roadway and culvert zone

• Successful lifting and levelling of the asphalt surface without milling or resurfacing

• Increased soil bearing capacity and compaction verified through post-injection DCP testing

• Formation of a hydrophobic, lightweight geo-composite layer that prevents future water infiltration and frost-related movement

• Zero excavation or material disposal required

• Permanent structural reinforcement achieved at a fraction of conventional reconstruction cost

Project Summary

Parameter	Details
Location	Racine, Québec
Structure Type	Rural road with HDPE culvert
Length Stabilized	≈12 m
Road Width	≈8 m (+1.8 m shoulders)
Culvert Diameter	900 mm (HDPE)
Injection Depth	1.2–1.6 m
Material Used	HydroFoam (4 lb/ft³ hydrophobic polyurethane)
Technology	Deep Soil Injection (DSI)
Duration	1 day
Traffic Impact	None – work performed under partial lane control

Conclusion

This project demonstrates the effectiveness of PURLIFT®’s Deep Soil Injection technology in reinforcing and restoring municipal infrastructure without excavation or prolonged disruption.

Working in partnership with Gestimaction, PURLIFT® stabilized the roadway, lifted and levelled the asphalt surface, and sealed water-saturated voids using hydrophobic polyurethane.

The Racine Road Stabilization Project stands as a prime example of how advanced injection methods can extend infrastructure lifespan, prevent seasonal deformation, and deliver a cost-effective, permanent solution for municipalities.