【作者】 刘洋；

【导师】 伊廷华；

【作者基本信息】 大连理工大学 ， 结构工程， 2025， 硕士

【摘要】 独柱墩曲线梁桥广泛分布于城市立交与公路匝道,其运营期受车辆偏载、温度循环等多因素耦合作用易产生爬移病害,严重则会造成桥梁失稳倾覆。因此,对在役独柱墩曲线梁桥进行爬移监测与倾覆风险评估具有重要意义。支座反力和抗倾覆稳定性系数是表征桥梁抗倾覆稳定性的核心指标,可为桥梁抗倾覆稳定性动态评估提供量化依据。本文以曲线梁桥考虑爬移病害的抗倾覆稳定性分析为主线,针对设计参数对抗倾覆的影响、运营期梁体爬移病害对抗倾覆稳定性的影响以及考虑两者因素影响的监测方案确定等问题展开研究。主要工作如下:(1)在设计参数对独柱墩桥梁抗倾覆稳定性的影响研究中,依据规范验算结果,给出较大倾覆风险桥型的研究较少。为此,基于现行规范中的抗倾覆稳定性评定方法,选取独柱墩连续梁桥作为研究对象,利用MIDAS Civil NX软件建立有限元模型,通过分析支座反力变化规律和抗倾覆稳定性系数,深入探讨了影响该类桥梁抗倾覆性能的关键设计参数,即曲率半径、支承方式、跨径组合、桥宽等,确定了倾覆高风险桥型。(2)在实际运营过程中,不同爬移病害会对桥梁抗倾覆稳定性产生不同程度的影响,而规范中的验算方法并未考虑此影响。为此,划分了不同的爬移病害模式,建立了考虑爬移量的有限元模型,分析抗倾覆稳定性,详细探讨了径向整体位移、纵向整体位移、平面刚性转动以及桥梁曲线半径变化等爬移模式对桥梁横向稳定性的影响,建立了不同爬移模式与抗倾覆稳定性的量化关系,系统评估了运营期累积位移对结构稳定性的影响程度,给出了梁体爬移的关键监测指标。(3)考虑到缺少实际运营过程中基于爬移监测数据的实时抗倾覆稳定性分析流程。为此,基于倾覆高风险桥型的筛选标准和梁体爬移的关键监测指标,提出了监测方案。开展了基于实际监测数据的桥梁抗倾覆稳定性评估技术研究,提出了考虑爬移效应的两阶段评估方法,并给出了预警指标。通过某实际运营的独柱墩曲线梁桥的监测数据分析,进行了抗倾覆稳定性两阶段评估,所提方法有效地发现了该桥抗倾覆稳定性不足的问题,基于该桥现状提出了四种典型加固方案,并通过有限元建模对比分析了加固效果,确定了加固方案。更多还原

【Abstract】 Single-column pier curved girder bridges are widely used in urban interchanges and highway ramps.During operation,these bridges are prone to creeping displacement under the coupled effects of factors such as vehicle eccentric loading and temperature cycles,which may lead to severe instability or even overturning.Therefore,monitoring creeping displacement and assessing overturning risks for in-service single-column pier curved girder bridges are of great significance.Bearing reaction forces and the anti-overturning stability coefficient are core indicators for evaluating bridge stability,providing a quantitative basis for dynamic anti-overturning stability assessment.This paper focuses on the anti-overturning stability analysis of curved girder bridges considering creeping displacement,addressing issues such as the influence of design parameters on anti-overturning stability,the impact of creeping displacement on stability during operation,and the determination of monitoring schemes incorporating both factors.That is,the radius of curvature,the support mode,the span combination,the bridge width,etc The main research work is as follows:(1)In studies on the influence of design parameters on the anti-overturning stability of single-column pier bridges,few researches have identified bridge configurations with high overturning risks based on code-compliant verification results.To address this,this study adopts the anti-overturning stability evaluation method specified in current design codes and selects a typical single-column pier continuous girder bridge as the research subject.A finite element model is established using MIDAS Civil NX software.By systematically analyzing the variation patterns of bearing reaction forces and the anti-overturning stability coefficient,the key design parameters affecting the anti-overturning performance of such bridges are thoroughly investigated,and high-risk bridge configurations prone to overturning are identified.(2)During actual operation,different types of creeping displacement can affect the anti-overturning stability of bridges to varying degrees,yet current design codes do not account for this influence.To address this issue,this study categorizes different creeping displacement patterns and develops finite element models incorporating displacement magnitudes to analyze anti-overturning stability.It systematically investigates the impact of various creeping modes—including radial global displacement,longitudinal global displacement,in-plane rigid rotation,and changes in bridge curvature radius—on lateral stability.Quantitative relationships between different creeping patterns and anti-overturning stability are established,and the effect of accumulated displacement on structural stability during operation is comprehensively evaluated.Finally,key monitoring indicators for girder creeping displacement are proposed.(3)Considering the lack of real-time anti-overturning stability analysis procedures based on actual creeping displacement monitoring data during bridge operation,this study proposes a monitoring framework based on both the screening criteria for high overturning-risk bridge configurations and key monitoring indicators for girder creeping displacement.Preliminary research was conducted on bridge anti-overturning stability evaluation techniques using actual monitoring data,resulting in a two-stage assessment method that accounts for creeping effects,along with corresponding warning thresholds.The proposed approach was validated through monitoring data analysis of an in-service single-column pier curved girder bridge,successfully identifying insufficient anti-overturning stability issues.Based on the bridge’s current condition,four typical reinforcement solutions were proposed.Their effectiveness was comparatively analyzed through finite element modeling,ultimately determining the optimal reinforcement strategy.更多还原