In complex underground environment of multilayer and multiple subsurface structures interaction

the new tunnel intrudes into the underground street piles

which might induce higher risk.The effects of the new tunnel intrusion process on displacements and internal forces of the underground street piles were studied by numerical simulation and field monitoring.The research shows:when excavating the lower part of the master cave

the moment of the pile section contacting the initial lining baseboard of pilot tunnel has a sharp increase;afer cutting pile

the axial force of the pile residual section in the lining of upper arch of the master cave has a obvious decrease

but the minimum principal stress of the lining has a obvious increase;compared with no existing subway tunnel

when the subway tunnel exists

the settlement of the pile foundation of the underground street will decrease for constructing new tunnel

the function of the third subsurface structure should be considered.The research conclusions could provide references for the disaster prevention of the new tunnel crossing the complex subsurface structures.