Alchatek Blog

A Utah-based geotech specialist partnered with a general contractor to address a critical DOT infrastructure challenge involving the replacement of an existing culvert on a major roadway in Utah. The project involved the installation of precast concrete slabs on both sides of the box culvert, designed to create a seamless transition from the culvert to the compacted road base.

Site Investigation and Challenge

During the design phase, engineers identified that constructing a compacted road base beneath the slab would inevitably leave voids underneath. These voids posed a risk of uneven support and potential rocking of the slab when subjected to heavy traffic load.

Proposed Solution

To address this, ¾” holes were drilled four feet apart to allow for injection rods to be inserted through the slab. The foam selected for this slab was AP Lift 440 structural foam due to its rapid expansion and high strength needed for DOT projects. This foam expands 17-19 times its original volume within 8-10 seconds of injection, ensuring comprehensive void filling. Dial indicators were used to ensure that there was no vertical movement of the slab during the injection process.  

Results and Conclusion

The entire operation was executed in approximately three hours, utilizing about 400 lbs of structural foam. This successful application filled all of the voids, providing uniform support for the precast slabs and enhancing overall road stability. The rapid curing properties of the foam allowed for swift project completion with minimal disruption to traffic.

Want more information on stabilizing soil with polyurethane?

Suburban Basement was hired to address significant voids beneath a slab foundation residence in Roseville, Michigan. The voids were suspected to have been caused by a compromised sewer line under the bathroom shower, resulting in extended leakage affecting a substantial portion of the home’s foundation. After plumbers discovered the issue, a local property restoration company managing the overall project engaged Suburban Basement.

Initial Assessment

The extent of the voids was assessed using 4-foot-tall plow markers as probes. The voids almost entirely engulfed these probes, indicating severe foundation undermining. The situation required a solution that could effectively fill large voids, bond with both soil and concrete, and perform well in wet environments.

Proposed Solution

Suburban Basement proposed using Alchatek's AP Lift 430 for the void filling. This material was chosen for its high expansion rate, making it cost-effective for large voids. Its ability to bond with soil and concrete, perform in wet conditions, and displace residual moisture from the plumbing leak made it ideal for this application.

Procedures

1. Drilled a systematic grid pattern of holes throughout the residence
2. Employed controlled injection shots to avoid excessive product usage and prevent lifting
3. Carefully filled all voids without causing any lifting of the foundation

Results

The project restored the foundation's integrity, filling all voids within a day. This efficient execution led to significant time and cost savings for all parties. The insurance company reduced relocation expenses, the restoration company delivered ahead of schedule, and the homeowners returned to their structurally sound homes earlier than expected. The outcome satisfied all stakeholders, demonstrating the effectiveness of the chosen solution in addressing complex foundation issues promptly and efficiently.

Want more information on geotechnical polyurethanes?

An old farmhouse with a wrap-around porch in Lake Orion, Michigan, presented a unique challenge. Beneath the porch lay an old cellar, initially used for coal storage but now serving only as a conduit for a well line into the residence. The primary concern was the inward buckling of the cellar walls, which posed a significant safety hazard. Many contractors suggested demolishing the porch and excavating the cellar, a solution that would have incurred substantial costs for both demolition and reconstruction.

Initial Assessment

Suburban Basement was engaged to address this issue. Upon evaluation, the team identified a more cost-effective and less invasive solution. The cellar, measuring 12 feet in length, 5 feet in height, and 5 feet in width, could be filled with foam to mitigate the risk of further wall collapse. This approach would spare the property owner the expensive and disruptive process of demolition and reconstruction.

Proposed Solution

The team proposed filling the cellar with Alchatek’s AP Lift 430 foam. This material was chosen for its extensive expansion rate, superior compressive strength, and lower application temperatures. These properties allowed for quicker application intervals while maintaining optimal temperatures between applications and minimizing ignition risks.

Procedures

1. Encapsulated the well line with sonotubes elevated above the cellar floor, ensuring future accessibility.
2. Installed OSB sheathing to define foam boundaries and prevent overflow.
3. Applied AP Lift 430 in layers, allowing cooling intervals between applications to optimize expansion and stability.
4. Coordinated with masons to prepare for CMU block installation at the containment boundary, ensuring seamless alignment with the existing foundation.

Results

The foam-filling solution successfully stabilized the cellar walls, eliminating the collapse risk while preserving functionality. Compared to traditional approaches, this method saved the client approximately $25,000 and maintained the home’s historic features. Completed in just five days, the project significantly outpaced conventional methods. Homeowners were highly satisfied with the noninvasive approach, cost savings, and seamless integration with their property’s historic character, demonstrating the effectiveness of innovative techniques in addressing complex structural challenges in historic properties.

Want more information on geotechnical polyurethanes?

The owner of a gas manufacturing facility contacted a Georgia-based contractor regarding significant floor settlement issues, with a warehouse slab dropping approximately 3-4 inches. The settlement made issues for the forklift traversing in and out of the warehouse and posed a risk to the workers.

Initial Assessment

Upon arrival at the site, the team conducted a thorough investigation. Using a probe, voids were identified beneath the slab, with the probe sinking up to 2 feet in some areas. A Dynamic Cone Penetrometer test revealed large voids 2-4 feet below the slab.  Poor drainage was evident, with improper crowning causing water to flow towards the building instead of away from it. Interestingly, a layer of unusually hard clay was noticed outside the building, suggesting possible prior remediation attempts.

Proposed Solution

AP Lift 430 was chosen for this project, providing an excellent injectable polyurethane grout solution. With its impressive 22x expansion capability and 7,200 psf compressive strength, it’s ideal for warehouse slabs that support heavy equipment. The grout’s hydrophobic properties ensure long-term stability by blocking water infiltration that could otherwise lead to void formation.

Procedures

1. Deep Injection (Void Fill)

• 32 injection points were established in a grid pattern (16 on each side) at 4 ft apart.
• At each point, the team injected 15-20 pounds of material at about 5 feet depth.
• A slight lift (approximately 1/16 inch) during this phase indicated successful void filling.

2. Slab Lifting

• Additional holes were drilled next to the wall, 3 feet from the wall, and 9 feet from the wall (6 feet from the first row).
• Injection began from the holes nearest to the wall and moved outward.
• Multiple passes were made, with some areas requiring 3-4 injections.
• Gradual lifting was employed to prevent slab cracking.
• Dial indicators were used to ensure even lifting across the warehouse floor.

Results

The project successfully stabilized the warehouse floor and restored it to its proper level. Effective void-filling addressed the underlying instability, providing a solid foundation for the slab. Success was evident in the restored functionality of the warehouse space and the elimination of safety hazards posed by the uneven floor. The property manager was pleased with the work and requested additional slab lifting services for their other facilities.

Want more information on lifting slabs with polyurethane?

Essential Details

Dates/Pricing (Discount Deadline Extended!)

Geotechnical Masterclass: March 25th - 27th, 2025

$695.00
This is special pricing for all who register before the end of the day, March 2nd. $745 March 3rd and later. ($50 discount for each additional participant.)

Location

Atlanta, GA

Discount

$50 discount for each additional participant.

Geotechnical Masterclass

Elevate your geotechnical expertise with our comprehensive masterclass covering cutting-edge techniques and solutions. Master:

• Polyurethane Concrete Leveling for sunken slabs
• Polyurethane Soil Stabilization for various soil types
• Geotechnical Testing with precision
• Deep Lock® soil stabilization procedures

Why Attend?

• Gain Hands-On Experience with state-of-the-art equipment
• Learn From Industry-Leading Experts with decades of experience
• Network with Peers and potential collaborators
• Boost Your Company’s Market Reach and capabilities

Consider the low cost of training vs. the high cost of job screw-ups and missed opportunities.

Transitioning from routine geotechnical work to more complex and high-stakes infrastructure and large-scale construction projects represents a significant growth opportunity for your career and business. Get the advanced skills and critical insights needed to tackle challenging projects and succeed in competitive markets confidently.

Join us for this transformative Geotechnical Masterclass. We’ll equip you with the knowledge and techniques to excel across all geotechnical project types.

Essential Details

Dates/Pricing

Geotechnical Masterclass: March 25th - 27th, 2025

$695.00
This is special pricing for all who register before the end of the day, February 25th. $745 February 26th and later. ($50 discount for each additional participant.)

Location

Atlanta, GA

Discount

$50 discount for each additional participant.

Geotechnical Masterclass

Elevate your geotechnical expertise with our comprehensive masterclass covering cutting-edge techniques and solutions. Master:

• Polyurethane Concrete Leveling for sunken slabs
• Polyurethane Soil Stabilization for various soil types
• Geotechnical Testing with precision
• Deep Lock® soil stabilization procedures

Why Attend?

• Gain Hands-On Experience with state-of-the-art equipment
• Learn From Industry-Leading Experts with decades of experience
• Network with Peers and potential collaborators
• Boost Your Company’s Market Reach and capabilities

Consider the low cost of training vs. the high cost of job screw-ups and missed opportunities.

Transitioning from routine geotechnical work to more complex and high-stakes infrastructure and large-scale construction projects represents a significant growth opportunity for your career and business. Get the advanced skills and critical insights needed to tackle challenging projects and succeed in competitive markets confidently.

Join us for this transformative Geotechnical Masterclass. We’ll equip you with the knowledge and techniques to excel across all geotechnical project types.

Essential Details

Dates/Pricing

Geotechnical Masterclass: March 25th - 27th, 2025

$695.00
This is special pricing for all who register before the end of day, February 25th. $745 February 26th and later. ($50 discount for each additional participant.)

Location

To Be Determined
(in Georgia)

Discount

$50 discount for each additional participant.

Geotechnical Masterclass

Elevate your geotechnical expertise with our comprehensive masterclass covering cutting-edge techniques and solutions. Master:

• Polyurethane Concrete Leveling for sunken slabs
• Polyurethane Soil Stabilization for various soil types
• Geotechnical Testing with precision
• Deep Lock® soil stabilization procedures

Why Attend?

• Gain Hands-On Experience with state-of-the-art equipment
• Learn From Industry-Leading Experts with decades of experience
• Network with Peers and potential collaborators
• Boost Your Company’s Market Reach and capabilities

Consider the low cost of training vs. the high cost of job screw-ups and missed opportunities.

Transitioning from routine geotechnical work to more complex and high-stakes infrastructure and large-scale construction projects represents a significant growth opportunity for your career and business. Get the advanced skills and critical insights needed to tackle challenging projects and succeed in competitive markets confidently.

Join us for this transformative Geotechnical Masterclass. We’ll equip you with the knowledge and techniques to excel across all geotechnical project types.

The owners of a college apartment complex in Georgia reached out to a local engineering firm after discovering a large void underneath the northwest end of the building. The issue was caused by stormwater collecting and flowing beneath the building's foundation. Over time, the foundation became exposed and now the grade has lowered by a foot from the original design.

Site Investigation and Initial Attempts

A dynamic cone penetrometer test revealed the soil was fragile, with two to three blow counts for the tested areas. Underpinning piles had been installed by the previous owner, but did not did not adequately stabilize the building's foundation. The shifting foundations caused the ceiling and wall in one of the top-level rooms to begin to crack and showed early signs of separation.

Proposed Solution

The engineering team recommended using injectable polyurethane grout. AP Lift 430 was selected for the job because of its high expansion of 22x and compressive strength of 7,200 psf. This polymer is also hydrophobic, which prevents water from causing further erosion of the void.

Implementation

1. Rod Placement: Injection rods were inserted horizontally into the void’s back, spaced 4 feet apart.
2. Foam Injection: Foam was injected through the rods until emerging from the exposed void area. This step ensured that the foam reached the farthest areas of the cavity.
3. Free-Shooting: The remaining exposed void was filled by direct foam application, ensuring comprehensive coverage.

Results and Conclusion

The end result was 658 gallons of expanded AP Lift 430 injected underneath the void. The polyurethane injection, combined with regrading work done in collaboration with a local engineering firm, successfully solved the issue and prevented further void formation underneath the student housing.

Want more information on geotechnical polymers and equipment?

Essential Details

Dates/Pricing

Geotechnical Masterclass: November 12th-14th, 2024 – $745.00

Location

Atlanta, GA

Discount

$50 discount for each additional participant.

Geotechnical Masterclass

Elevate your geotechnical expertise with our comprehensive masterclass covering cutting-edge techniques and solutions. Master:

• Polyurethane Concrete Leveling for sunken slabs
• Polyurethane Soil Stabilization for various soil types
• Geotechnical Testing with precision
• Deep Lock® soil stabilization procedures

Why Attend?

• Gain Hands-On Experience with state-of-the-art equipment
• Learn From Industry-Leading Experts with decades of experience
• Network with Peers and potential collaborators
• Boost Your Company’s Market Reach and capabilities

Consider the low cost of training vs. the high cost of job screw-ups and missed opportunities.

Transitioning from routine geotechnical work to more complex and high-stakes infrastructure and large-scale construction projects represents a significant growth opportunity for your career and business. Get the advanced skills and critical insights needed to tackle challenging projects and succeed in competitive markets confidently.

Join us for this transformative Geotechnical Masterclass. We’ll equip you with the knowledge and techniques to excel across all geotechnical project types.

Essential Details

Dates/Pricing

Geotechnical Masterclass: November 12th-14th, 2024 – $695.00
(Special pricing for all who register before October 7th at 5pm Eastern. $745 after.)

Location

To Be Determined
(in Georgia)

Discount

$50 discount for each additional participant.

Geotechnical Masterclass

Elevate your geotechnical expertise with our comprehensive masterclass covering cutting-edge techniques and solutions. Master:

• Polyurethane Concrete Leveling for sunken slabs
• Polyurethane Soil Stabilization for various soil types
• Geotechnical Testing with precision
• Deep Lock® soil stabilization procedures

Why Attend?

• Gain Hands-On Experience with state-of-the-art equipment
• Learn From Industry-Leading Experts with decades of experience
• Network with Peers and potential collaborators
• Boost Your Company’s Market Reach and capabilities

Consider the low cost of training vs. the high cost of job screw-ups and missed opportunities.

Transitioning from routine geotechnical work to more complex and high-stakes infrastructure and large-scale construction projects represents a significant growth opportunity for your career and business. Get the advanced skills and critical insights needed to tackle challenging projects and succeed in competitive markets confidently.

Join us for this transformative Geotechnical Masterclass. We’ll equip you with the knowledge and techniques to excel across all geotechnical project types.