CALCULATION OF DRIVEN PILE BEARING CAPACITY. ANALYTICAL METHODS AND ISSUES

The relevance. Deep foundations, especially piled ones, is a common technical solution for various buildings and structures. These types of foundations are used in unfavorable engineering geology conditions with weak soils, when the external load should be transferred to the strong deep laying stratum. This type of foundations is known as well as more reliable shallow foundations, as it decreases soil settlements and uneven deformations. Although pile foundations are used on a broad scale all over the world the preciseness of analytical evaluations (or calculations) of bearing capacity is not even close to the desired level yet. The main aim of the research is to carry out a series of analytical calculations through application of various methods and series of field practical tests of the displacement piles. Objects. The initial data for the research was working documentation and field practical piles tests that were held as a part of construction project of a multifunctional, multistorey complex in Moscow region. Methods. Analytical calculations of bearing capacity of piles were performed with application of various methods such as broadly known Tomlinson and Nordlund methods and the method proposed in Russian standard – SP 24.13330. Results. Pile to soil interaction is a very complex process that depends on numerous factors. The mechanics of this interaction could hardly be mathematically modeled these days, which predefines the necessity of using engineering, empirical or half-empirical, analytical methods. The performed comparison between the analytical calculations and the practical tests results has shown substantial discrepancy. Besides, the research shown a straight correlation between engineering geology complexity and the calculations results discrepancy level.