The legal procedure of geotechnical ground investigations in Estonia is established by “The procedure of engineering geological investigations” Regulation no.71 of Minister of Economic Affairs and Communications.Read more
Geotechnical investigations in Estonia are technically regulated by European Standard EN 1997: Eurocode 7: Geotechnical design: Part 1: General rules and Eurocode 7: Geotechnical design: Part 2: Ground investigation and testing.
In engineering practice are used many synonyms for geotechnical site investigation as for example engineering geology, soil investigation or ground investigation. According to Eurocode 7 ground investigation is the component part of geotechnical design.
Geotechnical investigations shall provide sufficient data concerning the ground and the groundwater conditions at and around the construction site for a proper description of essential ground properties and a reliable assessment of the characteristic value of the ground parameters to be used in design calculations [EN 1997-1, 3.2.1 (1)].Read more
In geotechnical field investigation different techniques and measurements are used- visual observation, inquiry, trial pits, boreholes, soil sampling for laboratory tests, static cone penetration, dynamic probing, field shear tests and load tests, measurement of depth of groundwater table and groundwater sampling for laboratory analysis, etc.
The results of field investigation and laboratory tests shall be compiled in ground investigation report. This report should consist of presentation of all available geotechnical information including test results and geological data, evaluation of information, assumptions made in the interpretations of test results.
Unlike for most construction materials ground conditions are never homogeneous or uniform. Ground conditions can vary depending on geological feature, soil type, presence or absence of groundwater, topography of ground surface and soil stress conditions.Read more
But design without ground investigations could be potentially dangerous especially when geotechnical conditions happen to change. The practice of ground investigations has shown that geological structure or soil conditions can largely differ on neighboring sites or even unexpectedly alter within small area of one structure. In these situations geotechnical design without proper ground investigation may lead to undesirable consequences such as flood, accumulation of humidity, undesirable settlement and deformations of the structure, danger of collapse of structure, etc.
Therefore it is important to clarify basic geological and geotechnical conditions in early phases of planning of structures in order to estimate all risks for design and construction.
If construction of structure includes considerable risks (very large structure, unusual performance requirements for structure, difficult ground conditions, difficult load conditions of structure, etc.) it is reasonable to divide investigation into several successive phases. Such investigations are generally described in 3 phases which can overlap: preliminary investigation, design investigation, checking of ground conditions.Read more
Preliminary investigation shall be carried out for instance to assess general suitability of the site, to detect possible soil or groundwater pollution by contaminants, to detect underground structures etc. Preliminary investigation gives oportunity to plan subsequent design investigation and ground conditions check during supervision of construction.
Design investigation shall be carried out to provide reliable information for an adequate design, to plan the method of construction and identify any difficulties that may arise during construction.
Ground conditions check shall be carried out as a part of supervision of construction. The aim of this checking is to detect possible deviations from ground type and properties, groundwater conditions assumed in the design (investigation). The principles used in design shall be checked to ensure that they are appropriate for geotechnical features of the ground and groundwater, which are encountered.
For simple structures and conditions (geotechnical category 1) the soil type and groundwater conditions are checked visually and compared with earlier recordings. For complex structures (geotechnical categories 2 and 3) geotechnical properties of the soil or rock in or on which the structure is founded or located should be checked. Additional investigations may be needed for determination of soil type, strenght and deformability parameters. Direct observations of groundwater conditions should be made if these greatly affect the method of construction or performance of structure, and also if dewatering, grouting or tunneling during construction strongly affects groundwater regime.
In order to compile price offer for your ground investigation we need data about structure or object: address of investigation, structure’s purpose and description (dimensions, number of floors, type of structure), geodetic map (site plan) with marked contour of structure. If we need additional information we will contact You.