Analysis of technical state changes of spillway concrete gravity dams in municipalities of Marijampolė and Kėdainiai district

The spillway dams are built when the pass of large floodwater and ice is necessary. These spillways can be: a) with gates b) without gates. Most of these dams have been used for more than 30 years, and due to various reasons (natural aging of materials, loading and various impacts: the mechanical, physical, chemical, specific) the properties of structures are changing and because of that the technical state of spillway decreases. The research of the technical state of concrete spillways is not sufficient. The aim of research was to investigate and to evaluate technical state of spillways in Kėdainiai district and Marijampolė municipalities, also to compare the results with those of previous investigations. The following structure diagnostic methods were used for investigations of technical state: laboratory works, visual method, non-destructive method for the estimation of concrete strength; the technical state was evaluated using methodology described in Standard STR 1.12.03:2006. Comparing the results of investigations performed in 2005 - 2012 with the results obtained in previous studies (1999-2005) it was found out, that the technical state : a) is stable in Kėdainiai distr. municipality (Kruostas) and Marijampolė municipality (Marijampolė II and Antanavas) spillways; b) is improved (due to its reconstruction) – in Marijampolės municipality (Marijampolė I); c) has worsened in deteriorated spillways of Kėdainiai distr. municipality (Akademija – Dotnuva and Juodkiškiai) and Marijampolė municipality (Kazlai and Netičkampis)Vytauto Didžiojo universitetasŽemės ūkio akademij