DEFORMATION CONTROL OF PILE FOUNDATIONS FOR A LONG-SPAN CABLE-STAYED BRIDGE UNDER CONSTRUCTION OF A LIGHT RAIL STATION WITH THE PILE-BEAM-ARCH METHOD

The soil between tunnelled spaces and bridge abutments was supported and reinforced by grouted with composite bolt piles to ensure security and stability of a long-span cable-stayed bridge before tunnelling a underground light rail station along sides of pile founndations of the bridge with pile-beam-arch (PBA) method. The settlement of piles and the structural internal forces of the bridge before and after grouted reinforcement were studied by FEA. The results showed that the maximum settlement of piles occurred at the end of tunnelling the upper soil strata of the station. After grouted reinforcement, the loose range and plastic range around the tunnelled surface were reduced. The settlement of piles was reduced by 28. 7% compared with that of the unreinforced state. The calculation results showed that the bridge structure could meet the specification requirements in the ultimate bearing capacity and normal service state considering displacement of bearings.