PBA暗挖区段单跨隧道施工阶段增量法与全量法结构计算分析OA

Based on the project of Beijing Subway Line 22(Pinggu Line),the stress and deformation of the structure in three construction stages are taken as the research focus.The incremental method and the total load method in the construction stage of single-span tunnel in PBA underground excavation section are analyzed and the calculation re-sults are compared.Firstly,the basic principles and applications of incremental method and total load method are introduced.Then,combined with Midas GTS NX geotechnical finite element analysis software,the structural stress in the construction stage of the selected engineering model is analyzed.It is found that the results calculated by the above methods are different.The main reason is that the incremental method,the step-by-step construction should be considered,the components and loads are also applied step by step,and the internal force and deformation are also balanced in stages;For the total load method,the simultaneity of force and deformation should be considered,which cannot truly reflect the step-by-step nature of construction.Therefore,the incremental method should be used in the design.This research result can provide reference for the design and construction of similar tunnel projects.