CALCULATION OF THE EFFECTIVE LENGTH OF COMPRESSED BORED HANGING PILES BASED ON THE BEARING CAPACITY OF THE TWO-LAYER FOUNDATION SOIL.

The article discusses a new method for calculating the effective length of bored hanging piles based on the bearing capacity of a two-layer foundation soil. This calculation problem is of particular importance when it is necessary to use piles of large length and large diameter. The calculation of a hanging pile according to the bearing capacity of the foundation soil adopted in regulatory documents is based on the occurrence of friction forces on the surface of the pile because of its movement (“disruption”) in the ground environment. It does not correspond to the behavior of the pile during operation. In practice, the disruption of the pile is unacceptable, therefore, for the safe operation of the pile, the coefficients of the working conditions are entered into the calculation. A new approach to the calculation of hanging piles by bearing capacity in multilayer foundation soils based on the account of friction-adhesion forces on the surface of the pile is proposed. The friction-coupling forces are caused by micro-displacements of the surface layers of the pile material because of its general deformation from the compressive load on the pile. The effective length of the pile is understood to be such a length at which the bearing capacity of the soil on its surface and under the lower end of the pile is effectively used. Due to this length of the pile, an economic effect is achieved in pile foundations. The above method of calculating the bored pile can be used in the calculations of other piles by material, method of immersion and the number of layers of the foundation soil.