Abstract: The ground surface settlements induced by the construction of subways using shallow tunnel construction method are hardly avoidable. As the cross-sections of subways are very large most of them adopt partial-face excavation method. So it is possible to use deflection distribution control method to distribute the final ground surface settlements into every construction stage and make the ground surface settlement control standard for each construction stage．In this way we can achieve the aim of integral control by controlling in every stages. But it is often not acceptable to use the parameters from geological exploration in numerical simulation which is relied by deflection distribution control. So back analysis is used as a complement method in getting the parameters adapt to numerical simulation. This paper describes the characteristics of direct back analysis, the qualification for modeling and the procedures for analysis. Application of a real subway showed that the proposed system could successfully forecast the ground surface settlement and approve the practicability of the deflection distribution control method.

Key words: back analysis, deflection distribution control, numerical simulation, optimized parameter, subway station