“Computational Civil Engineering - "Intersections" International Journal

“Computational Civil Engineering 2005”, International Symposium 211- the level system with zero at the Baltic Sea – “MB”,The heterogeneity of the distribution of these systems on the territory of ourcountry, as well as of the datum levels has lead to the necessity of creating acompact and homogenous network for the whole territory of our country, having asdatum level the Black Sea. This network was called “level system with zero at theBlack Sea, adjusted in 1975” and marked “0” – 1975.2. THE IMPORTANCE OF THE HIGH-ACCURACY LEVELLINGNETWORKS EXISTING ON THE TERRITORY OF ROMANIAThe general conclusion drawn from the studies and research made is that the earliermeasurements have enough accuracy, and are a reliable database and informationbase for later processing. Thus, the differences between the measurement of leveldifferences made earlier and the new ones are acceptably small, and are within ±2-3mm for the common points.After analysing the abovementioned level systems we were able to formulategeneral considerations on the quality and importance of the existing high-accuracylevelling networks.2.1. The level system with the datum level at the Adriatic Sea - MAThis network includes points especially in the Banat area. Considering the age ofthese points, as well as the fact that most of them have disappeared from the landand can only be found in the level archives, the need of points with level in thissystem is very reduced.2.2. The level system with the datum level at the Black Sea - Constanta - MNCThe findings based on the points that make up this type of network, as well as thelarge dimensions of the areas in which the works in this system have been carriedout lead to the conclusion that this network represents a fundamental structure onthe territory of our country.Thus there is a relatively large area covered by a basic topographic plan, withlevelling carried out in the MNC reference system; a large part of the state-ownedtriangulation system's points have levels in this system; on the majority of thelevelling lines there are many other materialised points.Moreover, the high-accuracy levelling routes of grades 1-4 in the MNC system arelinked to a series of other geometrical levelling routes of grade 5 and technical ones(which also have levels in the MNC system).