Comparative analysis of determination methods of Nepa-Botuoba anteclise coarse soil strength properties

The article compares direct and computational methods of strength determination on example of coarse soil characteristic of the southern and central areas of the Nepa-Botuoba anteclise, the territory of which is associated with the active development of oil and gas condensate fields. The paper presents the main methods for coarse soil strength estimation as well as the factors that determine strength characteristics. The method of shear strength (in-plane shear) according to GOST 20276-2012 “Soils. Field methods for determining strength and compressibilitycharacteristics” and the computational method “Methods for assessing the strength and compressibility of coarse clastic soils with silt and clay aggregate and silty and loamy soils with coarse grain inclusions” developed at the Far Eastern Research, Design and Technological Construction Institute (FERDTCI) is used to assess the strength of coarse soil. Two types of eluvial-deluvial soil were tested: sample A - silty coarse soil, sample B - coarse silty loam. Using direct and computational methods the indicators of cohesion and internal friction angle are obtained for typical eluvial-deluvial soils distributed in the region under consideration. Comparison is given to the results received. Silty coarse soils are characterized by greater divergence in the values of cohesion and internal friction angle obtained by direct and computational methods than coarse silty loams. The article provides the data on the study of the precision characteristics of the direct shear test method. The value of cohesion and internal friction angle calculated by the direct shear test correspond to the theoretical concepts of the nature of soil strength. The differences between the results of the direct and computational methods of strength determination are comparable with the reproducibility characteristics of the direct method. The methods of assessing the strength and compressibility of coarse clastic soils with silt and clay aggregate developed at FERDTCI are today the main ones in our country for obtaining the strength parameters used for final calculations of strength of coarse clastic soil massifs in the foundation of buildings and structures of II and III classes.

Nepa-Botuoba anteclise, coarse soil, strength characteristics of soil

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