Pile Foundation Detection and Deterioration Rehabilitation for Existing Railway Bridge
The piers of an existing railway bridge displaced in a flooding event.To rapidly detect the soundness of the pile foundation in a non-destructive manner,velocity sensors that measure pressure at two varying velocities were employed,and the sensors were mounted on small platforms cut out in the pile shaft that served as action spots for transient excitation.A total of 5 corner piles were detected,among which,3 piles did not demonstrate defects,while 2 piles signaled local defects.Two piles without defects and one pile with defects were cored for verification.The core samples of the three piles agreed with the detection results.A two-phase retrofitting scheme was implemented:in phase 1,the work was associated with emergency relief to prevent further progress of the deterioration,including cleaning up the hill slopes and deloading,digging circular water interception ditch,driving steel sheet piles on the empty side of the pile foundation,and backfilling and reverse-pressing;in phase 2,the taken measures were required to achieve permanent retrofitting effect,including adding upward slant holes for water drainage,frame beams of anchor rods and anchor piles,enlarging the pile cap and adding extra piles.After the two phases of retrofit,the operation of the railway line resumed.The monitored stresses in piles as well as the displacements of piers and rails are all normal.
万方数据
维普
