On interpretation of the data of soil cone penetration tests

Abstract

© 2019 Tomsk Polytechnic University, Publishing House. All rights reserved. The relevance of the research is caused by the ever-increasing use of the method of cone penetration tests of soils, changing the requirements for design of foundations in modern construction and revealed significant discrepancy of physical and mechanical characteristics of the soils determined using cone penetration tests according to the tables of SP 11-105 and the data of laboratory tests. The main aim of the research is the comparative analysis between laboratory studies and cone penetration tests in the study area. Objects: soil basement of the foundations of a residential complex in Kazan, Rodina Street. Methods: analysis of domestic and foreign experience, cone penetration tests of soils, laboratory studies of physical and mechanical properties of soils, statistical processing of test results. Results. Using the example of the construction site for a complex of residential 9-25-storey houses in Kazan the authors have shown the impossibility of applying the SP 11-105 tables to determine the mechanical characteristics of a number of soils. This conclusion was made on the basis of processing the results of 125 points of cone penetration tests, passed to a depth of 20 m, drilling of 59 boreholes to a depth of 40 m, as well as laboratory tests of soil samples with determination of strength and strain properties. Comparative analysis of field and laboratory researches for various engineering-geological elements on the study area shown that the values of the strength and strain characteristics of soils obtained using the method of cone penetration test, are significantly overestimated, and the carrying capacity of the piles is underestimated. It is proposed to solve this problem by creating regional building standards in the field of cone penetration tests of soils for Kazan and the Republic of Tatarstan. This will improve the accuracy of engineering and geological surveys and increase the economic profitability of construction.