SELECTION OF DESIGN VALUES FOR PHYSICAL-MECHANICAL PROPERTIES IN THE CONSTRUCTIONS ON COLLAPSIBLE SOILS

Abstract

The article substantiated the necessity of detailed geological-engineering surveys during the design and construction on collapsible soils. A landslide incident on the Cahul-Giurgiulești railway line at 74th km was highlighted. Among the main causes there were the soaking of collapsible soils and the development of suffusion processes. A brief historical overview of the study of collapsible soils in Republic of Moldova was provided. The results of theoretical and laboratory studies aimed at further revealing the nature of collapsible soils were presented. The impact of additional soil moisture on the values of physical-mechanical property characteristics was studied. Based on the moisture-density theory, the dependencies of strength on consistency were constructed. It was established that the decrease in the strength of collapsible loams over time might have been caused by the disruption of rigid cementation bonds of structural cohesion (Cc) and the reduction of hydrocolloid cohesion (Σw) under conditions of changes in the existing natural moisture regime (consistency) due to additional moisture from engineering activities and the rise of the groundwater level. Recommended design values for physical-mechanical characteristic parameters for construction projects were provided.