Multi-objective design and optimization of squeezed branch pile based on orthogonal test

In recent years, the emergence of the squeezed branch pile has presented a new avenue for civil engineering, offering a distinctive structure and favorable mechanical characteristics. Squeezed branch piles have strong compressive, uplift, and horizontal load resistance capabilities. Due to the existence of discs, the geometric parameters of squeezed branch piles are abundant but important. This article selects number of discs, disc diameter, disc squeeze angle, and disc spacing as the main influencing factors on the bearing capacity of squeezed branch piles and conducts a qualitative analysis of their mechanical properties. The aim of this article is to analyze the different bearing performances of squeezed branch piles through orthogonal experimental design, simulate test conditions using finite element software ABAQUS, obtain relevant data, and finally determine the weight ranking and optimal combination of influencing factors through range analysis to provide better guidance for engineering practices. Through multi-objective optimization design, six optimization objectives including compressive performance, compressive economic efficiency, uplift performance, uplift economic efficiency, maximum horizontal displacement and maximum bending moment of pile body were analyzed. The analysis methods used included comprehensive balance method, queue scoring method, principal component analysis method, entropy weight method, and analytic hierarchy process. The conclusions obtained are similar, and based on the judgment, the squeezed branch pile with 4 discs, disc diameter of 2.5D, disc squeeze angle of 35°, and disc spacing of 3D is considered as the optimal combination under consideration of all optimization objectives.