The paper deals with a part of a research project which focuses on the development of a corpus-driven semantic-grammatical description of Russian prepositional constructions. In this paper, we investigate the structure of synonymous and quasi-synonymous semantic relations of primary and secondary prepositions in the Russian language. The metalanguage for the identification of a prepositional meaning is described. The methodology for processing corpus data and calculating frequency characteristics of prepositional constructions in modern Russian texts is presented. We demonstrate results of our methodology for the semantics of the locative rubric.