Common Geotechnical Problems in Construction

Building any structure requires knowing what will be under it and how the land will affect the building. However, when you’re working with larger construction projects, it becomes even more important that the architect and engineer know exactly what is going on in the soil structure around the building.



There are a number of issues that may turn up during a geotechnical survey. Some of these may be sorted in order to build a truly safe structure, but others may cause the cancellation of the entire project. This all depends on the problem found and its severity.

Geotechnical Problems on Construction Sites

To avoid problems in the future, it’s essential that you conduct a complete geotechnical survey before beginning any building. However, this becomes even more necessary if you are building a commercial structure or a building with more than two floors. A geotechnical engineer can let you know exactly what issues there are and may be able to suggest ways to work around them or resolve the problem completely.

Here are some of the more common geotechnical problems found on construction sites:

Unstable Slopes

Not all building sites are flat and that means you need to consider the slopes that surround the building site. Slopes that are made up of different types of soil or rock are likely to collapse, which can destroy your site. To mitigate the problem, some builders will put up a retaining wall, but you still need to know the composition of the slope in order to create the proper type of retaining wall.

If anything is built on the unstable slope, there is the possibility of the entire structure collapsing or sliding down with the face of the slope when it goes.

Ground Water Seepage

If there is too much water in the soil, it can begin to seep into the foundation of the building project, causing potential damage. In addition to causing flooding in basements and parking garages, seeping groundwater may change how the soil beneath the structure reacts. This can cause instability and even sunken areas on the construction site.

Water can be extremely damaging, so it’s not surprising that an entire construction project may be put on hold due to ground water seepage.

Unstable Soil

In some areas, the ground is not stable enough to simply build as normal. This often occurs when the bedrock is considerably far below the surface and there is sand or other types of unstable soil above it. Since this can cause shifting later on, the building needs to be carefully designed to account for this possibility.

Even a small seismic event can shift soil that is already unstable. This may cause any structure built on it and not properly secured to tilt. Floors become uneven and the walls lean. The changes may put considerable pressure on the walls and foundation, making it possible that the entire building will collapse.

Poor Drainage

One of the things that geotechnical engineers check is the drainage of the building site. Certain types of soil, such as clay, are very poor at draining water and this can cause a problem. Once the building is constructed, if the drainage is not properly handled, the water may pool around the foundation and cause lasting damage. In the event of a storm, for example, flooding may occur and you certainly want to know about that before it happens.

Each of these problems has solutions, but in order to implement them you need to know what the problem is. This is an area where you will most certainly require a geotechnical survey. It will uncover some of the potential dangers in the area and will also make recommendations on how to prevent disaster if you choose to continue with the build.

What is Included in a Geotechnical Survey?

A ground survey or geotechnical survey is meant to show any potential weaknesses in the area where you plan to build. To prevent any future problems, it’s an essential part of the pre-construction checklist.

A geotechnical survey will begin with the preliminary study. The engineer will look at the proposed construction design and then assess ground conditions. They will examine the topography, which tends to provide quite a lot of information to the engineer about what type of soil or ground water conditions exist. The preliminary study doesn’t just look at the environmental factors, however. It also considers nearby buildings and how they will be affected by the new structure.

During this phase, the geotechnical engineer will study the geological map of the area and take into consideration any natural resources that may be present. These include oil, minerals, and natural gas, among other resources. They will also determine seismic activity for the area and look at any aerial images of the site.

The next step is the ground investigation, where the engineer will go to the site and walk around to get a better idea of what is involved. They will usually dig trial pits and boreholes, collecting samples to examine in the lab.

The reason for all this digging and drilling? The engineer must be aware of the sheer strength and compression ability of each layer of soil. They’ll need to understand what the density is like and just how well it will withstand the pressures of the building above it.

When all the information has been collected and analysed, the geotechnical engineer will prepare a site investigation report. This report will provide information on ground conditions and will make recommendations to ensure the security of the structure about to be built. It’s essential that this information be heeded. Failure to do so could result in some pretty horrific results.

When a building is constructed on poor ground, without the necessary precautions, it could collapse and kill people. This has occurred repeatedly throughout history and is almost always a result of taking shortcuts or ignoring recommendations from engineers. 

What Types of Projects Require a Geotechnical Engineer?

There are many different types of construction projects that will require examination of the surrounding area and the composition of the soil and land below the construction project. Projects include:

-      Dams and levees

-      Retaining walls

-      Houses and buildings of all types

-      Shipyards

-      Refineries

-      Roadways

-      Tunnels

-      Bridges

-      Streetlights

-      Landfills

-      Pipelines

-      Sewers

To prevent having to redo your project, or danger to those living and working there, extensive testing must be carried out and the area properly surveyed to ensure it can support the type of structure that will be designed and built.

Of course, different structures will require different types of reinforcement. A tunnel is very different from a shed and will require knowledge of the changes in soil throughout the tunnel, as well as how they are likely to react. It’s impossible to know this without studying, which is why an engineer is such a useful person to have around.

How to Find a Geotechnical Engineer

Most building engineer companies can direct you to a geotechnical engineer and some, such as Integrated Designs, have this type of engineer available. They will carry out a series of tests, in addition to investigating imagery from the site and doing walkthroughs to scan for potential issues.

If you aren’t sure you wish to hire a specific engineer, it may be a good idea to ask them about their prior experience with situations similar to yours. You’ll also want to know what their process is, so you can determine if the engineer is sufficiently thorough. Not all sites require bore holes and subsurface investigation, but if the geotechnical engineer does not expect to carry out this type of testing, they should be able to explain their reasoning.

The engineer will also be able to explain their thoughts on the existing site, based on issues you have already dealt with and their previous experience in the area. Often, entire neighbourhoods will be affected by similar issues, such as bedrock or groundwater seeping. In this case, the engineer may already know what problems tend to arise in the area and will help you avoid the same issues other builders faced.

Construction can be affected by many things, but with the help of a geotechnical engineer, you can avoid the most serious mistakes. Hire an engineer and have the ground survey done before you go any further with your construction, to avoid future tragedy. You won’t regret it.

Are you in need of a geotechnical engineer? Integrated Designs offers ground surveys and other essential services to keep your buildings safe. Schedule your appointment now.