Uncategorized · 29 July 2020

Step by step geotechnical research

What is Szczecin geotechnical research ? What are their types and why are they made? When planning any construction, the area should be recognized in terms of soil and rock, and the level of groundwater should be determined. 

Therefore, specialized tests are carried out on a given construction plot, in characteristic locations tailored strictly to the terrain conditions, as well as to the indicated engineering tasks. What are the most common types of geotechnical surveys?

First – drilling

Drilling is the primary method by which information is obtained about soil or bedrock. Drilling is carried out by geotechnicians using manual sets, hammer sets or mechanical drilling rigs . Manual drilling is a depth of several meters. They can be made on condition of favorable land. However, it sometimes happens that the tested soil – embankment or native – is very strong, it may also have an admixture of stones and debris, as a result of this manual drilling is impossible to perform. Then – but it all depends on the depth of the reconnaissance – mechanical percussion sets are used, or for greater depths – specialized mechanical drilling rigs. Mechanical drilling rigs are mounted on wheeled or even tracked vehicles specially designed for this purpose. Mechanical drilling rigs can drill at any depth. It all depends on the size and power of the drill rig.

Second – geotechnical dynamic sounding

Geotechnical dynamic sounding means the geotechnical field survey of the so-called leading parameter, which is determined for loose native soil. This is the degree of compaction ID or IS compaction index as used for embankments. The conducted test is performed by dropping a mass of a certain weight from a specific height. Then the number of such strokes is counted, which fall to a certain depth of drive of the normative cone. For this purpose, probes with different weights and drop heights are used. It all depends on the depth at which ground reconnaissance is carried out.

Third – geotechnical static probing

Geotechnical static probing complements geotechnical drilling. Static probing is performed using, among others CPT probes. These are specialized measuring instruments. With their help, geotechnicians determine deformation and strength parameters of the probed medium. What is this examination about? It is a static pressing of the measuring tip into the substrate. This tip is equipped with a cone and a friction sleeve. The probes are mechanical and electronic. This results in a so-called continuous measurement. The extended CPTU cones, which are equipped with several pore pressure sensors, can also be used. This modern geotechnical researchare necessary to determine the degree of plasticity and compaction of the soil. This happens taking into account the humidity or even water failure of a given soil medium. Soundings are also used to verify such geophysical methods by which voids and soil loosening are identified.

Fourth – geotechnical laboratory tests

However, nothing is quite as easy as it may seem. So-called complex conditions may arise in a certain area. Therefore, in order to obtain different and very precise parameters of the tested soils and rocks, soil samples are subjected to specific laboratory tests. In laboratories, static strength tests and density tests are performed.

Fifth – VSS rigid plate

The VSS rigid plate is widely used for specialized engineering work. Thanks to it, the condition of the embankment soils is determined. Geotechnical tests carried out with the use of a rigid VSS slab determine the bearing capacity and compressibility of the subsoil . These are the parameters that have a direct impact on its density. With this plate, geotechnicians also determine the so-called settlement curves, and also determine the deformation index. All this happens thanks to the measurement of specific primary and secondary deformation modules.

Sixthly – a light dynamic album

The test performed with the use of a light dynamic slab is aimed at determining the soil compaction in excavations. The load-bearing capacity of embankments is also determined in this way, which are made for the construction of roads, parking lots and all kinds of foundations. The test does not require additional loads. Its result shows the settlement values ​​as well as the dynamic modulus of deformation. By making quick and simple calculations, geotechnicians convert them into a static module and a compaction index. In Poland, it is a non-standard examination.

Seventh – calculations of the stability of slopes and slopes

Geotechnical tests that are carried out for investments designed on sloped areas additionally require soil stability analysis. Stability is determined in order to eliminate mass surface movements, i.e. the possibility of possible landslides, landslides, slides and other negative phenomena dangerous for humans and the environment. Stability calculations also indicate the use of an appropriate technique for securing slopes and slopes at the stage of construction works and after their completion.

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