【作者】 李洛克；

【导师】 谭忆秋；

【作者基本信息】 哈尔滨工业大学 ， 道路与铁路工程， 2012， 博士

【摘要】 传力杆与混凝土接触面的损坏是引起水泥凝土路面传力杆装置发生传荷失效，并造成道路横向缩缝结构过早损坏的重要原因之一。针对水泥混凝土路面传力杆的传荷失效问题，本文以模型分析法研究了传力杆的力学特性，以试验的方式展示了传力杆在多种破坏模式下的失效过程，从传力杆与混凝土接触面力学性能退化及混凝土保护层开裂两个角度揭示了传力杆发生传荷失效现象的物理机理。以建立理论模型的方式将传力杆的三种传荷失效过程进行力学简化，应用数值方法模拟了三种破坏过程中传力杆周边混凝土内的裂纹演化行为，进而提出了水泥混凝土路面缩缝结构临界车辆轴载控制指标的试验及数值计算方法。本文的工作可以总结如下：首先，建立了考虑传力杆与混凝土、面层与基层接触面力学行为的水泥混凝土路面三维有限元模型。通过改变车辆轴载大小、温度梯度条件及缩缝结构组合特征，研究了传力杆的力学特性，确定了水泥混凝土路面缩缝结构易发生损坏的最不利位置。在此基础上，开发了传力杆与混凝土接触面力学性能试验系统，并针对传力杆的多种失效模式设计了相应的试验方案。其次，利用试验系统，开展了传力杆试件的静力极限、拟静力疲劳及加速锈蚀试验，模拟传力杆与混凝土接触面在三种破坏模式下的失效过程。以试验过程中采集的声发射信号为基础，从传力杆与混凝土接触面力学性能退化及混凝土保护层开裂等角度探讨了传力杆在三种破坏模式下的传荷失效机理，进而提出了缩缝结构临界车辆轴载的试验方法。然后，根据传力杆与混凝土接触面破坏过程中的物理现象，抽象出传力杆的极限破坏行为力学模型、疲劳松动行为力学模型及传力杆-锈蚀产物-混凝土保护层耦合作用力学模型。应用数值方法，模拟了三种失效模式下传力杆周边混凝土内的裂纹演化行为，进而提出了缩缝结构临界车辆轴载的数值计算方法。最后，提出了增加传力杆在除冰盐环境中服役耐久性的改进措施。设计了新型钢质传力杆的构造形式，开发了不影响钢质传力杆锚固端力学性能的耐久型防锈涂料，研究了非金属GFRP传力杆的设计、验算方法。上述研究有助于正确地评估传力杆的工作状态，了解传力杆在不同破坏模式下的失效过程；同时，为设计更加耐久的传力杆装置提供了可借鉴的方案，为减少水泥混凝土路面横向缩缝结构的破坏提供一定的依据和参考。更多还原

【Abstract】 Damage of the contact interface between dowel bar and concrete (CIDC) is themain reason for the transferring failure of dowel bar and early damage of shrinkjoints in the cement concrete pavements (CCP). Focused on the problem oftransferring failure, mechanical characteristics of dowel bar were studied in t histhesis. The failure process of dowel bar under different damage mode was explodedby means of tests, and the physical mechanics of transferring failure were presentedby the following two aspects: mechanical performance degradation of CIDC;cracking of covering layer.3types of transferring failure of dowel bar weremechanically simplified by means of theoretical model establishment, and the crackextension in the peripheral concrete of dowel bar was simulated by numericalmethod. And then the test and numerical calculation method of critical guidepostsof vehiculary axel load were indicated. The work in this thesis can be summarizedas the follows:First of all, the three-dimensional finite element model of CCP was established,the different contact situations of dowel bar to concrete and surface to base wereconsidered. By varying the combination characteristic of axel load, temperature andshrink joints, the mechanical characteristics of dowel bar were researched. Theunfavorable position of shrink joint where is most easily to be damaged was located.On this basis, testing system of CIDC was developed. According to differentdamage modes, different test schemes were accordingly designed.Secondly, by using the testing system, limited bearing capacity test, fatigue testand accelerated corrosion test were separately implemented to simulate the failureprocess under three damage modes of CIDC. Based on the obtained signal of soundemission test, the mechanics of transferring failure under three types of differentdamage modes was studied in the perspective of CIDC’s mechanical performancedegradation and cracking of covering layer. And then the test method of criticalvehicle axel load of shrink joint structure was proposed.Once again, according to the physical phenomenon of CIDC during its damageprocess, the following models of dowel bar were abstracted. They are limited damage model, fatigue loose model, dowel bar-corrosion product-covering layercoupled model. By applying numerical method, crack extension behavior in theposition of peripheral concrete of dowel bar was simulated under the three failuremodes. And then the numerical calculation method of critical vehicle axel load ofshrink joint structure was indicated.Finally, the durability improve method of dowel bar under the cryohydriccircumstance was proposed. Structural form of newtype steel dowel bar wasdesigned. Endurance coating mixture was developed, which is not affecting themechanical performance of steel dowel bar’s anchored-end. Design and checkmethod of GFRP dowel bar was also studied.Researches in this thesis are conducive to correctly evaluate the work status ofdowel bars, and also let people know about the failure process of dowel bar underdifferent damage modes. At the same time, offered engineers a referential scheme todesign more durable dowel bars, and presented a series of references to reduce thedamage of transverse shrink joint of CCP structure.更多还原