THE RESULTS OF LABORATORY STUDIES OF THE OPERATION OF MODELS OF PYRAMIDAL-PRISMATIC PILES ON THE EFFECT OF VERTICAL PULLING LOAD IN CLAY SOIL

This paper presents the results of laboratory tests of models of pyramidal-prismatic piles on the effect of vertical pulling load. The experiments were carried out in clay soil. It is established that models of pyramidal-prismatic piles, depending on the size of the pyramidal section, can have both greater and lesser resistance compared to prismatic and pyramidal (control) piles. Thus, it was found that the resistance of pyramidal-prismatic piles to the pulling load is 1.19-1.80 times higher than the resistance of a model of a prismatic pile with a cross-section size of 20×20 mm. Compared with the model of a prismatic pile with a cross-section size of 30 ×30 mm and with the model of a pyramidal pile (with a cross-section size of 30×30 mm at the top and 20×20 mm at the bottom), the models of pyramidal-prismatic piles have less resistance (by 6-45%). An increase in the size of the upper section of the pyramidal part of the PPP has a more significant effect on increasing their resistance to pulling out than an increase in the length of their pyramidal section. Correlations have been established that can be used for a preliminary assessment of the resistance of pyramidal-prismatic piles to the pulling load relative to the resistance of traditional (prismatic and pyramidal) piles.