The paper explores the role of key words-nouns and their constant collocates-verbal predicates in the semantic structure of English scientific-technical texts in the field of civil engineering. It is focused on the static and dynamic aspects of the essential content of the text, methods of its formal representation and ways of expression. Key nouns are seen as bearers of the essential static content of the text. They are singled out on the basis of quantitative criterion keeping in view their frequency of occurrence in the text and the number of passages in which they are used. The dynamic aspect of the text is represented by a list of verbal predicates linked by key nouns. Static and dynamic aspects of the text are closely interconnected.