Three Major Factors That Affect The Type Of Excavation Method Used In Construction Projects

by Derrick Gordon

In construction, excavation involves utilizing heavy equipment or explosives to remove the top layer of ground (soil, rocks, or vegetation) to make room for the installation of a foundation. Nonetheless, there are several methods of conducting an excavation project. 

In some instances, a property owner or developer may have a preferred method of excavation they want to be utilized. However, before their preferred mode of excavation can be used, several factors need to be considered before implementing the method. Thus, irrespective of the method of excavation you want to be utilized on your construction project, it doesn't necessarily have to be the ideal method.

Thus, here are three critical factors you need to consider before excavation services commence.  

Type of Subsoil at the Site

Whether you a constructing a small building or a multi-story building, the type of subsoil at the site will determine how the excavation for the foundation will get done. As a result, before you hire any excavation services, a geotechnical survey of the site needs to get conducted by an accredited surveyor.

The purpose of the geotechnical survey is to determine the type of subsoil at the site and establish whether or not it is ideal for your preferred method of excavation. For instance, if the subsoil is too soft, the surveyor may recommend utilizing shoring excavation methods instead of sloping excavation to prevent the soil from collapsing or caving in during the excavation work.

Water Table Height

For construction sites with a low water table, underground water is not a significant factor affecting how the excavation gets done. However, if the construction site has a high water table, there is the risk of flooding.

As a result, if your construction site has a high water table, you will need to include dewatering pumps and water-tight sheet pilling as part of the excavation service. Dewatering pumps are utilized to pump water out of the excavation site, whereas water-tight sheet pilling gets used to prevent the excavated area from flooding.

Thus, before hiring excavation services, you also need to determine if the water table level at the site will affect the excavation works.

Surrounding Buildings and Utilities

If the construction site has installations such as adjacent buildings or utility lines, then the excavation method will have to factor in the preservation of such installation. Remember, if the excavation damages another person's property or utility lines, you will get sued and held liable to compensate the affected parties.

Thus, to avoid such inconveniences, it is always advisable to have the excavation contractor and a surveyor determine if the proposed excavation method will affect the building and utility lines within the vicinity of the excavation site.

Suppose the adjacent buildings are at risk of getting destabilized or damaged by the excavation. In that case, the excavation contractor may have to underpin the foundations of the surrounding buildings before the excavation work can commence. Secondly, suppose you have utility lines such as sewer lines or water supply lines running through the site. In that case, you will have to request the local municipal council to have them diverted to avoid damage during the excavation.