Soil excavation and carrying capacity

Today is a big excavation. You have a row of excavators. Your house plans still look like new from the printer. You have risked the excavation area. You are ready to go.

Before you sink the shovel to the ground, there are a few things you should know. Ground excavation and carrying capacity are the most important components of the construction process for several different reasons which I will discuss in this article.

Removing all organic material

When digging the foundation of a building, all organic material must be removed. Ingredients such as grass, plants, soil, and top roots. In some cases, you may have to dig deeper than expected to remove all organic material. In this case, you may be faced with expensive difficulties because you have to import granular fillers.

No standing water in every excavation

The next component that plays an important role in water. There should be no standing water in every excavation. If there is water, the source needs to be investigated to determine what precautions need to be taken to remove or eliminate water. The underground water surface also plays an important role in the structural integrity of buildings. Most of the Building Code outlines the important steps to be taken when the foundation is within a certain distance from the water level.

The right soil carrying capacity

Once organic has been removed, soil that has the right soil carrying capacity must be present. Different soils have different carrying capacities. For example, when dry clay has a higher bearing compared to other types of soil, compared to sand which is much lower. The minimum carrying capacity of land determined by most Building Codes is 75 Kpa. For example, sand is at a minimum requirement with a carrying capacity of 75 Kpa.

Another thing to remember is that this land must be original and not disturbed. In case the material must be imported, the material must be compacted properly so that it meets the minimum carrying capacity of the soil. Recall that most City Governments need land engineers to certify compaction.

Some additional precautions

If you are digging at a depth of more than 6 feet, there are some additional precautions that need to be taken. This is related to work and security measures. There are some acceptable and unacceptable excavations.

There are four main types of soil namely clay, silt, sand, and grains. Clay and mud look similar when dry. When mud becomes saturated, it turns into soft and fast sand which differs from clay. Sand is a type of soil with the lowest soil carrying capacity. Granular is slightly higher. For most residential applications and for water drainage purposes, granular material is my preferred type of soil because it offers a fairly good carrying capacity but does not retain water, thereby eliminating the problem of water penetration.


Remember, the house you build is only as good as the land being built. Take all necessary precautions to ensure you build on suitable land, … READ MORE