DEGREE OF PILE EMBEDMENT IN A STRIP FOUNDATION BASED ON THE RESULTS OF TESTS ON SMALL-SCALE MODELS

Abstract

Physical modeling was conducted using small-scale models of a strip pile foundation with a low grillage on bored and driven piles to investigate the interaction between the piles, the grillage, and the soil, as well as the differences in pile behavior depending on the method of their installation in the soil. Static load tests were also performed on individual piles with the same geometric parameters as those in the strip pile foundation. A comparison was made of the degree of load transfer for bored and driven piles within a strip pile foundation, and the dependence of the degree of load transfer on pile length and spacing was analyzed. A review of studies on the interaction of piles and the pile cap within a strip pile foundation demonstrates the presence of performance-enhancing effects due to the mutual interaction of the piles and the engagement of the strip pile cap through the reaction of the soil foundation.

Current regulatory documents recommend considering the joint performance of piles and the grillage, but existing analytical models do not fully account for the factors affecting the bearing capacity of the pile foundation. The conducted studies confirm the influence of the grillage on the bearing capacity of the pile foundation, as well as an increase in the degree of realization of the piles’ bearing capacity within the foundation, which is influenced by complex physical-mechanical processes occurring in the soil under load and other factors.

Approaches to determining the allowable load on bored piles within a strip pile foundation underestimate the actual bearing capacity of the strip. Current approaches to determining the allowable load on bored piles in strip pile foundations underestimate the actual bearing capacity of such foundations compared to those using driven piles. The development and refinement of existing methods for determining the bearing capacity of strip pile foundations, which will account for improved operating conditions of piles in a group and their interaction with the grillage, will allow for the realization of the bearing capacity reserve of pile foundations, which will improve the technical economic performance of strip pile foundations and enable more cost-effective decisions to be made when designing pile foundations.