Optimal Control Of Pile A Nchor Support For Deep Foundation Pit Considering Soil Viscosity Effect

Deep pit engineering is often close to subway stations and other high-rise buildings,and the displacement variation value of its support structure in the whole construction and use process has attracted the attention of scholars and engineers,and the optimization of the displacement value of the foundation pit has become a difficult point for research.Based on the research background of optimizing displacement value of deep foundation pit engineering support structure with more clay,the main research results obtained on deep foundation pit structure displacement are as follows:During the optimization of the displacement value of the base pit,the deformation amount of the support pile will change with each other,and the pressure value of the base pit will be between the static soil pressure state and the active soil pressure state with the change of the pile deformation,so the influence of the support results when the soil pressure change is studied.Set different soil pressure values for research,according to the static state soil pressure calculation for an increase of 2.3 times the bending moment value will increase 1.9 times,soil pressure in the static soil pressure gradually converted into active limit state soil pressure,the displacement change of the upper layer of the pile is greater than the change of the lower displacement,displacement value growth and internal force growth show a positive correlation.In terms of base pit displacement value optimization,it is carried out from the angle of optimizing beam stiffness and adjusting shaft force with optimization control theory.Before selecting the reasonable beam stiffness,first study the concrete effect of the beam on the pile structure of the base pit,that is,when there is a difference in the material parameters of the pile body,the maximum displacement difference of the same node of each guard pile is reduced by more than 65%,the maximum bending moment difference between the piles is reduced by more than 49%,and the anchor rope axis force changes with time and the displacement trend of each anchor rope node changes with time.Moreover,when the anchor rope prestress loss,the beam narrows the maximum displacement difference of the same beam node to less than 1mm,the difference between the maximum shear force and the minimum shear force of the same node decreases,and the bending moment difference decreases by more than 50%.The beam plays a lateral adjustment role in ensuring the overall deformation of the support.Finally,a reasonable stiffness is selected.When the displacement of the support structure is controlled by linear optimal secondary type,the displacement value is reduced by more than 29%,and the displacement optimization percentage difference between the two models is verified by finite element software,which proves the feasibility of using the optimal linear secondary type for displacement optimization.In this paper,the study of anchor support displacement of more clay deep pit piles is optimized,which provides guidance for the prediction of displacement optimization in pile anchor support structure.