Why Soil Compaction Is Important in Construction

Unless you’re a contractor or engineer yourself, you might not realize the importance of soil compaction in construction in Hudson, CO. Soil compaction affects the foundation and drainage. If the soil under your building isn’t properly compacted, you could end up with floods, a cracked foundation, a shifting building and other things that will affect your property’s stability and value.

Here’s an overview of soil compaction and why it’s so key to a stable building.

What is soil compaction?

Imagine trying to build a structure on the beach: the sand is bound to shift and settle over time. That, in turn, shifts the building itself, since it’s not built on stable ground. Soil compaction aims to reduce the void space between soil particles—essentially, the goal is to pack the dirt tightly so the building is on terra firma. Soil is classified as either granular or cohesive—granular soil has high sand, gravel and silt content, whereas cohesive soil has clay content and may feel smooth or greasy to the touch.

When compacting soil for a building foundation, engineers and contractors aim for 95 percent compaction. Soil testing will indicate the maximum dry density of the soil through compaction, as well as the ideal moisture content. Ideally, 95 percent compaction provides a sturdy base for foundations and footings, among other structures.

Soil needs to be compacted any time it’s disturbed during construction or it’s used for fill. This is also important when you use sand, gravel or crushed stone underneath a slab. The less room there is for the soil to settle and shift, the sturdier your foundation will be.

How is soil compacted?

Soil is generally compacted with heavy equipment—steamrollers and other types of rollers help increase density and provide a smooth surface for footings, foundations and other construction. You might see smooth rollers, padfoot and tamping foot rollers or pneumatic rollers used on bigger jobs. Depending on the soil type, one type of equipment may be more suitable. Smooth rollers and pneumatic rollers are better for granular soils, while padfoot and tamping foot rollers are better for cohesive soil. For smaller, confined spaces, tamping rammers are used to shore up the soil density before placing structures. These rammers are particularly effective on cohesive soils.

What happens if the soil is not compacted?

Even a layperson can see the effects of soil that was not properly compacted. Look around: do you see buckling sidewalks, cracked driveways and cracks in the foundation? Another sign of poor compaction is puddling around the building, a sure sign that the ground has shifted and is no longer graded properly for drainage.

All of these problems can turn into major issues down the line—repairing a cracked or shifting foundation is expensive and difficult. It’s best to work with engineers and contractors who realize the importance of soil compaction in Hudson, CO from the outset.

For civil engineering services and general expertise in the Hudson area, call High Plains Engineering & Design, LLC today.

Categorised in: Geotechnical Engineering