Our subsoil expertise gives you an insight into the geotechnical properties of the soil on your building site.
Subsoil expertise
Our subsoil expertise gives you an insight into the geotechnical properties of the soil on your building site.
How the subsoil expertise works
In pile-driving core probing, we drive a hollow core into the ground. The soil is pressed into the hollow core, the so-called pile-driving core probe. When we pull it out, we obtain a soil sample in layers. When carrying out the pile-driving core probe, we collect important soil parameters for the preparation of the subsoil report.
Important soil parameters (DIN 1055-2)
Measured for the load acceptance for buildings, for example:
- Weights
- Shear strength
- Friction angle
- Cohesion
During the geochemical preliminary investigation, we analyse the soil samples taken from the pile-driving core probe for chemical substances. Preliminary exploration allows us to determine whether the soil is contaminated or which pollution class it belongs to before excavation. In rare cases, it is recognised by the disposal site as a declaration analysis.
Testing and measurement
We use various tests and measurements to determine the soil type, layer thickness, base pressure and much more. The results of these tests and measurements form the basis for the soil expertise.
Subsoil expertise
In the subsoil report, we summarise the information from the pile-driving core sounding, the tests and measurements. Based on our experience, regulations and standards, we provide an opinion on all relevant parameters. Our subsoil expertise provides you with information on the groundwater level, base resistance, frost resistance and many other parameters. They serve your structural engineer as a basis for the calculation of the statics or foundation. This is the only way to ensure that subsidence does not cause cracks in the building.
If the groundwater level is high, it can also be very important for waterproofing the cellar.
Subsoil expertise ... short and sweet
- What does a ground survey cost?
The question "How much does a ground survey cost?" cannot be answered in a generalised way. The cost of a subsoil survey depends on the size of the property and the depth to be drilled. For a subsoil survey with an area of approx. 100m² and a maximum drilling depth of 5m, builders should expect costs of between €1000 and €1500.
- What is a subsoil expertise?
A Subsoil expertise provides information about the condition of the soil in the construction area. It is often also called a subsoil investigation or generally a soil expertise. The mechanical values of the soil are determined in a subsoil survey. These include, for example, the density, the friction angle or the coefficient of rigidity. The subsoil report also provides information about the soil group, the soil class, the layered structure and the groundwater situation and infiltration capacity.
- Why do you need a ground survey?
A Subsoil expertise is essential for a reliable calculation of the structure's statics. The foundation, i.e. the type and size of the foundation, is determined based on the soil parameters. The groundwater level is of great importance for the basement and the waterproofing.
- When should a ground survey be carried out?
A subsoil report has no limited validity. The time at which a subsoil investigation is carried out is therefore irrelevant from a technical point of view.
From a commercial point of view, however, it can be advisable to commission a subsoil survey before purchasing a property. This can avoid unpleasant surprises such as an excessively high groundwater level or contamination. If a subsoil survey is carried out before the property is purchased, it is also advisable to examine the soil for contamination by means of a preliminary geochemical investigation. The total costs are usually less than €2,000. And in the event that you buy the property, you can use the reports.
