Expansive Soil's Effects on Your Foundation | RMG Engineers - Geotechnical Engineering in Denver, Co

Summary

Jerry, a contractor, faced challenges with Colorado's expansive clay, causing house foundations to shift. He discovered Rocky Mountain Group, experts in geotechnical engineering, who offer solutions like helical piers, deep concrete piers, micro piles, and driven piles for stable foundations. RMG also innovates with systems like Tell Ferma, using high-strength mechanisms to lift structures above clay's effects, ensuring long-lasting stability.

Takeaways

• 🏠 **Expansive Clay Threat**: Expansive clay poses a significant risk to building foundations in Colorado's Front Range, causing movement and damage over time.
• 📚 **Learning Experience**: Jerry, a contractor, learned about the expansive clay issue the hard way through a challenging project.
• 🌱 **Natural Formation**: Expansive clay is a geological condition that has been developing for over a million years.
• 🔍 **Expertise of RMG**: Rocky Mountain Group (RMG) offers comprehensive geotechnical engineering solutions to counteract the effects of expansive clay.
• 🏗️ **Foundation Solutions**: RMG utilizes four main types of deep foundation systems: helical piers, deep concrete piers, micro piles, and driven piles.
• 🛠️ **Innovative Approaches**: RMG goes beyond traditional methods, offering solutions that treat the expansive soil itself, like over dig or sub excavation systems.
• 💡 **Dead Load System**: RMG can design a dead load system with a shallow foundation heavy enough to counteract clay uplift without extensive removal.
• 🏡 **Stiffened Slab Systems**: For low to moderate clay, RMG uses stiffened slab systems that place the building on a single concrete mat.
• 🚀 **Tell Ferma Technologies**: RMG specializes in Tell Ferma, an innovative system that uses high-strength mechanisms to lift a structural slab away from expansive soil.
• 📞 **Contact RMG**: For geotechnical and structural engineering services to ensure long-lasting foundations, contact RMG through their website, phone, or email.

Q & A

What is expansive clay and why is it a threat to building foundations?

Expansive clay is a type of soil that expands when wet and contracts when dry, similar to a dry sponge absorbing water and then shrinking as it dries. This movement can cause significant shifts in building foundations, leading to structural damage.

How did expansive clay form and how long ago did this process start?

Expansive clay was formed over a million years ago due to geological processes. The specific conditions that led to its formation are not detailed in the script, but it's implied that it's a naturally occurring phenomenon in the region.

What areas in Colorado are particularly affected by expansive clay?

The script mentions that expansive clay is a significant issue throughout Colorado's Front Range, affecting many areas where foundations are built directly on this type of soil.

How does the Rocky Mountain Group address the challenges posed by expansive clay?

The Rocky Mountain Group offers a full suite of geotechnical engineering solutions. They perform deep geotechnical evaluations to understand soil types and threat factors, then apply various deep foundation systems or alternative solutions to stabilize the building on expansive clay.

What types of deep foundation systems does the Rocky Mountain Group use?

The Rocky Mountain Group uses four general types of deep foundation systems: helical piers, deep concrete piers, micro piles, and driven piles.

What is a helical pier and how does it help with expansive clay?

A helical pier is a large steel screw-like structure that is twisted into the ground to anchor a foundation. It provides stability by reaching deep into the soil where the clay's expansive properties have less impact.

Can you explain the concept of a deep concrete pier in the context of expansive clay?

Deep concrete piers are large concrete columns that are dug deep into the ground and socketed into stable bedrock. They bypass the expansive clay layer, providing a solid base for foundations.

What are micro piles and how do they address the issues with expansive soils?

Micro piles are deep foundation elements made with high-strength, small diameter steel casing and/or a threaded bar. They are designed to be stable even in highly expansive soils, providing a secure anchor for foundations.

How does the driven pile system work and what loads can it support?

Driven piles are long, slender columns that support extremely large loads. They are installed by impact hammering, vibrating, or pushing them into the earth, providing a deep and stable foundation in expansive soils.

What alternative solutions does the Rocky Mountain Group offer to treat expansive soil itself?

The Rocky Mountain Group can recommend over dig systems or sub excavation systems that replace the problematic clay soil with a low expansive soils mix, reducing the expansion directly impacting the foundation.

What is a dead load system and how does it offset the uplift of expansive clay?

A dead load system is designed with a shallow foundation that is heavy enough to offset moderate uplift caused by expansive clay. It's a cost-effective solution that doesn't require the significant expense of removing the clay.

Tell Ferma technologies is mentioned as an innovative solution. How does it work?

Tell Ferma technologies use high-strength lifting mechanisms to lift a post-tensioned structural slab away from the harmful effects of expansive soils. This system eliminates the need for slab forms, crawl spaces, adjustable posts, and voided walls, and it's adjustable for ongoing foundation stability.