COMPARATIVE ANALYSIS OF THE RESULTS OF STANDARD AND ACCELERATED FIELD TESTS OF PILE FOUNDATIONS IN PERMAFROST SOILS

Abstract

The relevance of the work consists in the analysis of the results of field control tests of soils with a static load on indentation with full-scale piles, performed according to accelerated and standard methods in conditions of permafrost spreading. The timing of soil testing by piles allows you to adjust and accelerate the pace of construction and installation work on the device of the «zero cycle» of foundations, reduce the time for making various design decisions and erecting technical systems aimed at ensuring the mechanical safety of the designed structures in terms of creating and maintaining the required temperature and strength regime of the foundation soils (thermal stabilization of soils) and its further control during the construction and operation of buildings and structures (geotechnical monitoring). The paper analyzes two calculation methods, provides an analysis of the rational use of each method. Objective: calculation and comparison of design loads treated during the production of static tests for pressing piles into the ground, based on the requirements of regulated and existing measurement methods (standard and accelerated) in cryolithozone conditions and assessment of the possibility of using one or another calculation method. Methods. At the first stage of the study, the issues of organization and technology of production of field control tests of piles in the northwestern part of the Amur region were considered by evaluating the information displayed in the domestic regulatory documentation: SP 25.13330.2020 and SS 5686-2020. The engineering and geocryological conditions of the work area are described. At the second stage, an assessment of 11 field tests was carried out, calculations and comparative analysis of the bearing capacity and design loads on piles were carried out according to the test results. Results. The obtained data are recommended to be used in the construction of buildings and structures on pile foundations in conditions of the spread of permafrost soils for monitoring and operational management of the pace of construction of the «zero cycle» of foundations, for assessing the economic component of the project and obtaining reliable and necessary data on the state of the geological environment.

Keywords

• bearing capacity
• working tested pile
• comparable soil tests with piles
• comparative analysis
• field tests
• deformations
• permafrost soil
• temperature regime
• design load
• foundation
• pile foundations