COMPOSITION AND STRUCTURE OF THE DISPERSE ZONE OF WEATHERING CRUST OF GRANITOIDS OF THE TERRITORY OF THE CITY OF CHELYABINSK

Abstract

Residual clay soils are the bases of industrial and civil buildings and structures in the Urals region. Therefore, the study of the composition, structure and properties of residual soils, serving as the bases for projected and under construction objects, is a primary task that contributes to a more rational conduct of all types of engineering surveys. The paper examines the results of investigation of structural strength, chemical and mineral compositions of residual clayey soils of the dispersed zone of the granitoids weathering crust of the Chelyabinsk pluton, their macro- and microstructure. According to the data of the investigations carried out, the dispersed zone of the weathering crust was subdivided into smaller subdivisions. Varieties in the thickness of residual clay soils are distinguished on the basis of qualitative (color, structural and texture features) and quantitative (physical and mechanical properties, structural strength) characteristics. Moreover, an attempt has been made to scientifically substantiate the isolation of varieties in the thickness of residual clay soils from the results of studying structural strength. Based on the analysis of the obtained results of studies, taking into account the classifications of different regulatory sources, the author shares in the general case the dispersed zone of the weathering crust according to the degree of structural strength into three varieties: structureless (residual clayey soil with secondary structural bonds acquired as a result of hypergenesis), weakly structural (weaklyclayey soil, which has strongly attenuated primary and also partially secondary bonds) and a structurally stable (residual clayey soil with strongly attenuated primary bonds). However, the conclusions drawn need to be confirmed through more studies, since the geotechnical information obtained as a result of the present study of the composition and structure of the dispersed zone of the weathering crust of granitoids of the Chelyabinsk batholith at three points is not enough.