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.For civil engineering projects under complex geological conditions with large settlement and fast deformation,the use of squeezed branch piles can significantly shorten the construction period and reduce costs.Due to the existence of discs,the geometric parameters of squeezed branch piles are abundant.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 determine the weight ranking and optimal combination of influencing factors through range analysis.In the analysis of compressive resistance capabilities,with compressive performance and compressive economic efficiency as the two main optimization objectives,the specific evaluation values are vertical settlement at the top of the pile and compressive bearing capacity per unit volume.In the analysis of uplift resistance capabilities,the specific evaluation values are vertical uplift at the top of the pile and uplift bearing capacity per unit volume.In the analysis of horizontal resistance capabilities,the specific evaluation values are horizontal displacement at the top of the pile and bending moment of the pile.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.This article also studies the effects of disc positions and soil parameters around the pile on the compressive performance of the squeezed branch pile and the stress of the soil at the pile end.The soil parameters mainly consider the elastic modulus,cohesive force,internal friction angle,and pile-soil friction coefficient of the soil.