考虑侧向土体作用的盾构掘进诱发桩基水平位移预测方法OA

[Objective]Existing studies on the horizontal displacement of adjacent pile foundations induced by shield tunneling mostly adopt the Winkler or Pasternak foundation model,while the Vlasov foundation model and the lateral soil action on piles are rarely considered.Therefore,this study investigates the influence of lateral soil action on the horizontal displacement of pile foundations.[Methods]Based on the Vlasov foundation model,the pile foundation was simplified as a homogeneous rectangular beam,its governing equation was derived,and the finite difference method was employed to calculate the horizontal displacement of the pile.The lateral soil action was then represented by concentrated forces acting on both sides of the pile.Matrix equations were established under two boundary conditions,namely,both ends of the pile being free and the pile head being fixed while the pile toe was free.The proposed model was verified through comparisons with measured data and existing methods,and a parametric analysis was subsequently conducted.[Results]The pile displacement curves obtained using the four methods exhibited consistent variation trends,and the horizontal displacement increased as the pile approached the tunnel centerline.The calculated results for the two cases were 5.12 mm and 10.9 mm,differing from the measured values by 1.5%and 9%,respectively.Compared with the Pasternak foundation model,the average calculation error was reduced by 86.9%.An increase in the excavation radius or tunnel burial depth increased the maximum horizontal displacement of the pile,whereas an increase in the pile-tunnel distance or soil Poisson's ratio decreased it.[Conclusion]The Vlasov foundation model considering lateral soil action can predict the horizontal displacement of pile foundations induced by shield tunneling with relatively high accuracy,and can provide a reference for the deformation analysis and safety control of adjacent pile foundations.