Abstract:This study delves into the degradation of interlayer connections within longitudinally connected slab ballastless track-continuous beam line bridge systems (LCLBS) caused by side pier settlement. Incorporating the effects of side pier settlement and discontinuous contact between layers, a nonlinear spatial model of LCLBS was developed and validated against a previously established theoretical model. Subsequently, the typical deformation modes of the LCLBS under side pier settlement, along with the evolution process, development trends, and locations of interlayer connection failure were thoroughly analyzed. The findings underscore the accuracy and reliability of the spatial model. Under side pier settlement, LCLBS manifested three distinct deformation modes: follow deformation, self-weight deformation, and hovering separation. Interlayer connection failure occurred above the settlement pier, the simply supported beam piers adjacent to the settlement pier, and the opposite side pier of the continuous beam bridge. Bearings on the simply supported beam piers adjacent to the settlement pier and on all piers of the continuous beam bridge were damaged. The clearance height at the slab bottom near the settlement pier was quantifiable by subtracting the deformation limit of the continuous beam bridge from the settlement value of the side pier. Furthermore, the length of each clearance zone expanded with the amplitude of the side pier settlement, exhibiting symmetrically distributed clearance lengths on both sides of the simply supported beam piers adjoining the settlement pier. Conversely, the clearance length at the pier on the opposite side of the continuous beam was solely dictated by the continuous beam's deformation, consistently maintained at 2.56 meters.
