GEOTECHNICAL INVESTIGATION

The main activity of SIA “Ģeo Eksperts” is the provision of geotechnical (geological, engineering & geological) investigation services. Geotechnical investigation is mainly carried out for the design of civil and industrial structures (single or multi-storey residential buildings, hangars, production buildings, transhipment terminals, etc.), design of road, rail and underground communications, as well as for other specific structures (wind generators, power line supports and lighting masts, etc.).

We also offer geotechnical investigation in the water area – for the design of bridges and berths, as well as dredging and bank strengthening works.

SIA “Ģeo Eksperts” offers a complete set of geotechnical investigation works:

  • Geotechnical drilling works;

Geotechnical drilling is necessary for determination of soil composition, soil sampling for laboratory analyses, determination of groundwater level, as well as specifying the borders of soil layers. Drilling works are mainly performed using drilling equipment; the manual drilling tool is less commonly used. The most common method of drilling is screw (auger) drilling as well as core drilling. Drilling methods are chosen depending on the task, the complexity of the building/structure and the expected geological cross-section. 

  • Cone penetration (CPT) with or without measuring the pore pressure in soil;

Cone penetration is one of the most widely used and recognised soil investigation methods in the world. Cone penetration can be performed on bound and cohesionless soils whose density level or hardness does not exceed the technical parameters of the probe device and equipment. The penetration is done to precisely determine the borders of soil layers, as well as to get an idea of the mechanical properties of soils in natural bedding conditions. Cone penetration can be executed either with an electronic type of cone (piezocone) or with a mechanical cone (Begemann type). SIA “Ģeo Eksperts” has the equipment for performing penetration with both types of cones, but due to the details of the information, piezocone type of probes is preferred. In case of weak, bound soils (sludge, clay), it is recommended to conduct probing with pore pressure measurement. 

The processing of CPT results are carried out in the original programs developed and licensed by the equipment manufacturer.

  • Dynamic penetration (DPSH);

Dynamic penetration super heavy (DPSH) is performed mainly in cases where the intended depth (due to dense, hard soil) is not achieved by cone penetration, or the anchoring of the cone penetration equipment is not possible due to the peculiarities of the surface layer of the territory. With the help of dynamic penetration, it is possible to specify the borders of soil layers, as well as determine certain parameters of mechanical properties. The essence of the DPSH method is that the cone probe is successively and continuously driven into the ground with a freely falling hammer (a 63.5 kg heavy hammer falls from a height of 0.75 m). In addition, the number of hammer blows needed to drive the probe in a fixed range of 20 cm is recorded. The probing operator records the number of blows per each 20 cm interval in the field log, thus continuing the recording until the depth required by the work task is reached. The processing of data of dynamic probing is carried out using the “GeoStru Formula” computer program.

  • Laboratory research;

Laboratory research is not carried out by SIA “Ģeo Eksperts” on its own, but at this stage, services of laboratories accredited in Latvia are being used. Ideally, a laboratory analysis program is prepared on the basis of the work task and the research requirements therein submitted by the customer. In case the customer has failed to submit the correct work task, SIA “Ģeo Eksperts” will prepare a laboratory program based on its experience and taking into account the complexity of the structure being designed. The number of samples taken must be sufficient to give a statistically correct reflection of the most characteristic properties parameters of a specific layer. 

  • Preparation of the report.

After the field inspections are carried out and the results of laboratory analyses are received, a geotechnical report of the particular object is prepared. SIA “Ģeo Eksperts” provides all the necessary information in its reports – general information about the object, the description of the applied methods, conclusions and recommendations, and the report attachments contain various graphical information, drawings, test reports and analyses protocols. 

The following regulatory framework is used in the preparation of a report:

LVS EN 1997-2. Eurocode 7. Geotechnical design. Part 2. Investigation and research of the construction base.

LVS EN ISO 14688-1. Geotechnical investigation and testing. Identification and classification of soil. Part 1. Identification and description.

LVS EN ISO 14688-2. Geotechnical investigation and testing. Identification and classification of soil. Part 2. Principles for a classification.

Regulations on the Latvian Construction Standard LBN 005-15 "Regulations Regarding Engineering Survey in Construction". 


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