CLASSIFICATION ON CONSISTENCY OF ORGANOMINERAL SOILS OF WESTERN SIBERIA

Abstract

Relevance. Classification of organomineral soils according to state standards require correction. Methods for determining classification consistency indicators give excessive values moisture content of the plasticity and liquid limits due to the high content of organic matter. Due to imperfect standards, their results are unreliable and the grounds are incorrectly classified, which leads to errors in calculations of the base of constructions. The expediency of determining the consistency of organics containing soils is doubtful, and in order to reduce costs in engineering and geological investigations, the authors propose to consider in detail the problem of classification of organomineral soils by the example of numerous experimental data obtained for soils in the West Siberian region and recommend еру changes to existing standards. The main aim of the research is to identify the relationship between consistency indicators and organic matter content based on the experimental studies of organic-mineral soils of Western Siberia and justify the use of the Atterberg limits applied for mineral soils. Object: organomineral clay soils typical for Western Siberia, picked on the territory surroundings of the city of Tomsk, oil and gas fields of Tomsk region and Khanty-Mansiysky Autonomous District. Research methods include a method for determining limits of liquid and plasticity (wL and wp) and organic content (Ir), as well as by analyzing the results using MS Excel and Statistica. Results. The authors have carried out the review and analysis of foreign methods for determining the classification indexes of consistency in engineering-geological surveys and considered the problems of their carrying out and applications for soils containing organic substances. The determinations of organic matter, moisture content and consistency were carried out, significant interrelations between the indices were obtained and regression equations were compiled. As a result, inconsistencies with the current classification of organomineral clay soils due to overestimation of the consistency indices are revealed, therefore, in relation to their uninformativeness, it is recommended to abandon their use for organics containing soils.

Keywords

• organic and organomineral soils
• liquid and plasticity limits
• organic content
• plasticity index
• classification of peats and organomineral soils