Geotechnical monitoring

In our country the needful legitimate basis for planning and further realization of technical observations of complicated constructed objects is determined with Slovenian standard for geotechnical planning SLOVENSKI STANDARD, SIST EN 1997-1 (may 2005), obligatory from January 1st, 2006. Republic of Slovenia adopted European standard EN 1997-1: 2004, Eurocode 7: Geotechnical design – Part 1: General rules with permission CEN, Rue de Staassart 36, 1050 Brussel, Belgium, which became main Slovenian standard on the field of geotechnical planning. Standard demands, that the objects must be constructed safe and high quality, therefore the following steps must be assured:

• All steps of construction should be attentively followed and monitored.
• With adequate technical observations the site of an objects and objects itself must be accompanied during and after the construction.
• Every object must be properly insured.

Observations and measurements of the construction and its surroundings must be realized regarded to the safety needs:

• During the construction process to notice on time, if there are particular needs for appropriate improvements or changes of the construction itself.
• During and after the construction with the purpose of predicting further reactions and stability of objects.

Technical observations must be accomplished:

• with the purpose of controlling reliability of long term behavior of objects
• to insure that after the construction objects will react regarded to initial demands.

Technical observations after the concluded construction are adaptable regarded to results acquired during the construction. On objects with possible long term negative influence on the surroundings areas and for all constructions which demolition could cause large financial damage or even harm human health technical observations are taking more than 10 years after the concluded construction or even during the whole life-time period of an object.

An important part of technical observations are geodetic measurements methods that enable determinations of movements and deformations of:

• geotechnical artificial objects like highways, railways, tunnels, bridges, dams, engine constructions, safety walls and all kind of embankments etc.
• horizontal and vertical movements of natural surface caused by snow- and land-slips, instability materials, human interfering on and under surface (mining,¸tunneling) etc.

Measured movements of determined control points on objects or ground surface are the basis for further deformation adjustment calculations, which are the mean information about the material nature and qualities and income data for final safety analyzes. By natural surface this data could bring important information about possible dangerous influence on surroundings areas and adequate estimation of its economical use etc.

Continuouos following movements of geotechnical objects enables fast and punctually human reactions, what beside the safety itself most often declares important financial savings.

Largeness of constructed objects itself and expected movements make monitoring of geotechnical objects somewhat unique. Expected (planned) largeness of movements determines needful accuracy of chosen measurements methods, while the largeness of an object itself determines the choice of the measurement method itself.

In general there are two main measurement approaches: classical terrestrial methods and GNSS (Global Navigation Satellite System).

Terrestrial methods are divided in two main groups:

• methods for vertical movements observation: differential leveling and trigonometric leveling
• methods for horizontal movements observation: triangulation, trilateration and poligonometric measurements.

GNSS methods which enables spatial determination of methods are:

• Static survey
• Fast-static survey
• Kinematic and
• RTK (Real Time Kinematic).

Our company supports all methods mentioned above.

Regarded to the largeness of expected movements of geotechnical objects our experts are well trained for working on all levels of accuracy:

• I. level of accuracy: movements between 20mm and 100mm
• II. level of accuracy: movements between 5 mm and 20 mm