Structures of bored piles: features of installation technology

Abstract

Currently, pile foundations are often used in engineering practice. Among the modern types of piles used for foundation structures, the option of foundations made of bored piles is definitely popular. They are used for various types of structures: bridges as part of highways, urban ring roads or high-rise buildings. The main problem in these cases is related to a reliable assessment of the bearing capacity of the pile and the development of a cost-effective design solution for foundation structures.
 The studies carried out in this direction confirm that the issue of determining the load-bearing capacity of piles remains relevant both at the stage of developing reliable design solutions and in the process of searching for an economically efficient option of the foundation constructions of buildings and structures.
 Taking into account the design features of bored piles and their installation technology add certain difficulties to the analytical methods of determining the soil bearing capacity of a single pile.
 The practice of using bored piles on construction sites followed by observation of deformations showed that the soil bearing capacity of the piles, determined by the analytical method of standards used at the stage of developing design solutions for foundations, is underestimated. Therefore, the total number of piles in the foundation needs to be optimized according to the results of further field tests. Geometric parameters of piles, such as length and diameter, in some cases can also be reduced at the stage of rationalization of the design solution of the pile foundation, based on the results of field tests. So, as a result, the underestimated value of the load-bearing capacity of bored piles causes an increase in the cost of construction materials, an increase in the cost of installing foundation structures and an increase in the cost of housing for the end consumer.
 The problem of reliable assessment of the soil bearing capacity of piles remains a relevant issue at the moment, as evidenced by the practice of designing foundation structures.
 The paper presents the results of the analysis of the structural features of bored piles, which are aimed at increasing their bearing capacity. Also, the paper examines the features of the technology of installing bored piles, which are determined by both the hydro-geological conditions of the construction site and the need to install the constructive features of the bored pile.