Geotechnics

Geotechnical pre-investigation

For a geotechnical pre-investigation this technology is of added value to find the weakest spots of a building area. Traditionally, before starting the construction, a geotechnical research is performed based a number soundings. These are limited to 1D  information and do not give a good idea of the variations in the subsurface. Possible factors that can have an influence on the stability of a construction are for example old trajectories of rivers, variations of the geology in the subsurface, ancient excavations, landfills, …..

For the stability study of large constructions it is of large importance to know the variation and the composition of the subsurface and more in particular the weakest spot to calculate the necessary foundation . An example of a problem that might occur by using traditional research is illustrated in figure 1 and figure 2. By interpolating the measurements from the two soundings (figure 1), one would say that there is a clay layer with constant thickness, however the variation can be very big locally (Figure 2). 

Figuur 1: traditional 1D research on site.

Figure 2: GroundXplorer interpretation based on 2D information.

An example of a case study can be found in Figure 3. Locally high values were observed (left side of figure 3). These indicate the presence of denser sands compared to the values in the middle or on the right of figure 3..

Figuur 3 : Local variation in bearing capacity of the subsurface.