GeoZone - Applied Geology & Geotechnics

Geotechnical Investigations

Geotechnical investigations are what GeoZone does best, and it has been our bread and butter for many years. However that is not to say that an investigation of this sort is a simple exercise and to this day we have never found two sites alike. The challenge is to extract the maximum amount of data from the investigation and it does take a practiced eye to accomplish this. Many factors come into play, the most obvious being the bearing capacity of the soils or rock which underlie the site, the occurrence of groundwater, the thickness of the clays and the structure of the soils. Clays will consolidate over time, possibly leading to settlement of a structure founded thereon if certain parameters are exceeded.

Clays can also heave due to seasonal fluctuations in the soil moisture content, wtih disastrous results for any building founded in these materials. Pinholing within the soils can lead to collapse settlement if the soils become wetted up due to influx of water into the soils.

Geotechnical challenges are always present, even when the soils or rocks aren't supposedly problematical. To cut for instance a 20 metre deep cutting for a road will cause geotechnical problems as the supporting soil and rock is removed. An understanding of the behaviour of the rock mass is imperative. The shear strength, spatial orientation of joints and bedding planes of the rock mass will control the stability of the slope, and in these high-risk situations good geotechnical data is paramount. And this can only be gathered by a thorough, targeted investigation.

Drilling, test pits, borehole radar, seismics, dynamic probing and careful field mapping are all tools used to model the geotechnical conditions underlyng a site. In addition we make use of the local laboratories for soil and rock testing to determine the engineering properties of the materials in question.

Due to our experience of carrying out and administering geotechnical investigations, ranging from the 185 m high Katse Dam in Lesotho to the suburban cracked house, we are well able to carry out a wide range of geotech work for a variety of different structures.

To build a structure on a geological medium can pose a range of threats if the geological medium is not understood. GeoZone is perfectly placed to assist in characterising the ground conditions and providing recommendations for founding any structure. In addiition we can assist in earthworks supervision, quality assurance and onging inspection of any geotechnical engineering works.

Geotechnical Investigations

GeoZone - Applied Geology & Geotechnics