桥面铺装结构性能数值仿真分析

【作者】 崔建伟；

【导师】 乐金朝；

【作者基本信息】 郑州大学 ， 岩土工程， 2005， 硕士

【摘要】 桥面铺装结构是桥面行车体系的重要组成部分,由于桥面铺装结构的受力模式不同于一般的路面结构,沿用原力学计算方法不能较准确地揭示桥面铺装的真实受力状态。本文采用三维有限元方法,研究了桥面铺装体系的力学特性和分布变化规律,为桥面铺装层体系设计和施工提供理论依据,达到改善铺装层受力和延长铺装层使用寿命的目的。 本文探讨了不同荷位对铺装层受力状态的影响,确定了纵向及横向最不利荷位。通过计算不同沥青混凝土面层厚度时铺装层的受力状态,研究了铺装层厚度变化对铺装层整体竖向位移、应力状况及表面弯沉等性能的影响,为选择合理的铺装层厚度提供了理论依据。利用各向异性线弹性理论和三维有限元理论,构造了一种正交各向异性接触模型,用于模拟铺装层与桥面板之间的接触状况,并考虑超载作用的影响,分别对层间应力及应变进行了力学计算与分析,结果表明,粘结状况对桥面铺装层的使用性能具有重要影响。 为了考察铰缝的受力情况以及铰缝状态对桥面铺装结构使用性能的影响,本文分别按照空心板间铰接完好和铰接完全破坏两种极限情况对铺装层的受力状态进行了分析,并分别采用线性单元和非线性单元对铰缝填装结构进行了模拟,比较分析了铰缝结构在车辆荷载作用下的受力状态。计算结果表明,铰缝状况对桥面铺装结构的应力分布具有重要影响。当铰缝完好时,能够明显改善铺装结构的受力状况,从而增强桥梁整体结构的安全性和可靠性。对简支梁桥梁端处桥面铺装层在车辆荷载作用下的变形和应力进行了分析,同时考虑了空心板端部处层间粘结状态和伸缩缝的影响,从而为空心板端部处铺装结构的补强设计提供了理论依据。 为了考虑温度变化对桥面铺装结构的影响,本文对桥面铺装结构在持续大幅降温条件下的应力分布进行了计算分析,同时分析了沥青混凝土材料性能对铺装层受力的影响。在此基础上,对开裂水泥混凝土铺装层上部沥青混凝土面层内的应力场进行了计算,并对裂缝宽度、降温幅度、起始温度等因素对其应力分布的影响进行了分析。为了探讨桥面铺装结构的疲劳开裂机理,本文对沥青混凝土面层的疲劳力学性能指标进行了分析研究,并对其在车辆及温度荷载下的疲劳寿命进行了计算。本文的研究结果为桥面铺装结构的设计提供了技术基础。更多还原

【Abstract】 Bridge deck pavement is an important part of bridge and vehicle system. Because the mechanical mode of bridge deck pavement is different from that of the usual pavement, the calculation method for pavement can not reveal the actual stress state of bridge deck pavement. In order to provide a theoretic basis for the bridge system design and to improve the stress distribution and to prolong the performance term of the bridge deck pavement, the mechanical properties of the bridge deck pavement are studied under various conditions by use of the three-dimensional finite element method.The influence of different load locations on the stresses and strains of bridge deck pavement is discussed in this dissertation. Therefore, the worst load location in vertical and horizontal directions is determined. By calculating the problems of bridge deck pavement with different thickness of asphalt concrete pavement, the influences of different thickness of asphalt concrete pavement on the vertical displacement, stresses and surface deflection of the bridge deck pavement are carried out. The results provide a theoretical reference for choosing rational thickness of the bridge deck pavement. By using the anisotropy theory and the three-dimensional finite element method, a contact model of anisotropy for the bonding structure is constructed, and the influence of the overloading contact stress and strain between the bridge panel and bridge deck is calculated and analyzed. The results indicate that the condition of the bonding structure is a key factor to guarantee the credibility of the bridge deck pavement.In order to discuss the effect of the joint part conditions between hollow boards, the stress distributions of the bridge deck pavement are respectively analyzed as the joint part is intact or totally destroyed. Meanwhile, the linearity element and nonlinearity element are respectively used to simulate the actions of the joint part. The results indicate that the stress distributions of the bridge deck pavement are obviously improved when the joint part is intact, and the stability and reliability of the bridge deck pavement are strengthened. Then, the deformations and stresses of the bridge deck pavement at tip position of assembly simple beam bridge are analyzed under the vehicle load, and the influence of bonding state between the bridge deck pavement and the bridge panels are considered. The results provide some theoretical references for design and construction of the bridge deck pavement at the tip position.The temperature stresses of bridge deck pavement are calculated under the condition of continually temperature drop. The influence of asphalt concrete performance on thestress state of the deck pavement is analyzed. In order to discuss the influences of crack width, the range of temperature drop and the initial temperature on the stress distributions of asphalt concrete pavement, many cases are calculated as a crack in the cement concrete deck existed. The mechanism of the fatigue damage of bridge deck pavement and its mechanical performance parameters are studied, and its fatigue life of the bridge deck pavement is predicted under the vehicle and temperature loads. The results in this dissertation can be used to guide the design and construction of the bridge deck pavement.更多还原