边墩沉降致连续简支桥段纵连线桥系统层间联结劣化规律

Deterioration Patterns of Interlayer Connections in Longitudinally Connected Line Bridge Systems on Continuous Simply Supported Beam Bridge Sections Induced by Side Pier Settlement

为研究边墩沉降致纵连板式无砟轨道-连续梁桥系统(纵连线桥系统)层间联结劣化状态,在考虑边墩沉降与层间接触不连续影响的基础上,建立纵连线桥系统非线性空间模型,采用前期提出的理论模型对其进行验证,据此分析边墩沉降下纵连线桥系统典型变形模式,层间联结失效的演化过程、发展规律及出现位置等。结果表明:建立的空间模型准确可靠;边墩沉降下,线桥系统会产生跟随变形、自重变形和悬停分离三种变形模式;沉降墩、与沉降墩临近的简支梁墩及连续梁桥另一侧边墩上方会出现层间联结失效,与沉降墩临近的简支梁墩、连续梁桥全部桥墩上的支座均会发生破坏;边墩沉降处板底脱空高度可用边墩沉降值减去连续梁桥变形限值进行描述;各脱空区长度均随边墩沉降幅值增加而增大,与沉降墩临近的简支梁墩左、右两侧区域脱空长度成正对称分布,连续梁另一边墩处脱空长度值只与连续梁变形有关,始终维持在2.56 m。

This study delves into the degradation of interlayer connections within longitudinally con-nected slab ballastless track-continuous beam line bridge systems(LCLBS)caused by side pier settle-ment.Incorporating the effects of side pier settlement and discontinuous contact between layers,a non-linear spatial model of LCLBS was developed and validated against a previously established theoreti-cal 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 set-tlement 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 settle-ment 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 contin-uous 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.Con-versely,the clearance length at the pier on the opposite side of the continuous beam was solely dictat-ed by the continuous beam's deformation,consistently maintained at 2.56 meters.