简支板桥桥面连续构造破坏机理及改善措施研究
发布时间：2018-10-29 18:18
【摘要】：简支梁桥的桥面连续构造可以有效地改善行车的平顺性提高桥梁的整体性能,因而在中小跨径桥梁中被广泛采用。然而在后期的运营过程中发现带有桥面连续构造的简支梁桥在桥面连续段尤其是连续缝处铺装层的表面产生了横桥向的贯通裂缝,有的甚至会形成坑槽,影响正常行车;同时桥面连续构造在设计时并不经过专门的分析计算而只通过一定的配筋来控制,随意性较大。因此研究桥面连续构造产生裂缝的原因并提出改善措施具有重要的理论和实际应用价值。首先,以中小跨径公路桥梁中常用的简支板桥作为研究对象,针对桥面连续构造在使用过程中易开裂的现象,对其在荷载作用下桥面连续构造的受力机理进行了弹性分析,导出了其应力的解析表达式。利用有限元分析软件建立了两跨桥面连续的简支空心板桥,对八种工况下桥面连续构造的混凝土和钢筋的应力进行了线弹性分析,并重点针对上缘开裂的现象进行了材料非线性的分析,分析了开裂后铺装层内钢筋的应力并估算裂缝宽度。其次,在考虑车桥耦合振动的基础上对此类桥梁进行了动力特性分析,给出了带有桥面连续构造的简支板桥和普通简支板桥的跨中的挠度时程曲线及连续缝处的弯矩时程曲线,计算了跨中的挠度动力放大系数和连续缝处的弯矩动力放大系数。最后,结合静动力的分析结果,利用导出的桥面连续段应力的解析式提出了相应的改进措施。研究结果表明:桥面连续构造在荷载作用下连续缝处的上、下缘的混凝土应力都超过了其抗拉极限强度而开裂;车桥耦合振动对连续缝处混凝土的裂缝开展也较为不利;采用低弹模材料或者粘贴钢板能够改善桥面连续的受力和裂缝扩展的情况,使用碳纤维板材及桥面连续段张拉预应力的方法效果不佳。研究结果可为桥面连续简支梁桥的评价及加固工程应用提供参考。
[Abstract]:The continuous construction of the deck of simply supported beam bridge can effectively improve the ride comfort and improve the overall performance of the bridge, so it is widely used in medium and small span bridges. However, in the later period of operation, it was found that the simple supported beam bridge with continuous structure of the bridge deck produced transversal cracks on the surface of the pavement layer in the continuous section of the bridge deck, especially at the continuous joint, and some even formed potholes, which affected the normal running of the bridge. At the same time, the continuous structure of bridge deck is controlled by reinforcement without special analysis and calculation. Therefore, it is of great theoretical and practical value to study the causes of cracks in continuous structure of bridge deck and to put forward improvement measures. Firstly, the simple supported plate bridge, which is commonly used in medium and small span highway bridges, is taken as the research object, and the stress mechanism of continuous deck structure under load is analyzed according to the phenomenon that the continuous structure of bridge deck is prone to crack in the course of using. An analytical expression of the stress is derived. A simple supported hollow slab bridge with two spans continuous deck is established by using finite element analysis software. The stress of concrete and reinforcement continuously constructed on the deck under eight working conditions is analyzed with linear elasticity. The material nonlinearity of cracking in the upper edge is analyzed, the stress of steel bar in the pavement after cracking is analyzed and the crack width is estimated. Secondly, on the basis of considering the vehicle-bridge coupling vibration, the dynamic characteristics of this kind of bridge are analyzed, and the deflection time history curve and the moment history curve at the continuous joint of the simply supported plate bridge and the common simply supported plate bridge with continuous deck are given. The dynamic magnification factor of deflection in span and the dynamic magnification factor of bending moment at continuous joint are calculated. Finally, combined with the static and dynamic analysis results, the corresponding improvement measures are put forward by using the derived analytical formula of the continuous section stress of the bridge deck. The results show that the concrete stress at the upper and lower edge of the continuous structure of the bridge deck under load exceeds its ultimate tensile strength, and the vehicle-bridge coupling vibration is also unfavorable to the crack development of the concrete in the continuous joint. Using low elastic modulus material or sticking steel plate can improve the continuous force and crack propagation of bridge deck, and the method of using carbon fiber sheet and continuous section of bridge deck tensioning prestress is not effective. The results can be used as reference for evaluation and application of continuous simply supported bridge.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U443.31;U445.7
本文编号：2298438
[Abstract]:The continuous construction of the deck of simply supported beam bridge can effectively improve the ride comfort and improve the overall performance of the bridge, so it is widely used in medium and small span bridges. However, in the later period of operation, it was found that the simple supported beam bridge with continuous structure of the bridge deck produced transversal cracks on the surface of the pavement layer in the continuous section of the bridge deck, especially at the continuous joint, and some even formed potholes, which affected the normal running of the bridge. At the same time, the continuous structure of bridge deck is controlled by reinforcement without special analysis and calculation. Therefore, it is of great theoretical and practical value to study the causes of cracks in continuous structure of bridge deck and to put forward improvement measures. Firstly, the simple supported plate bridge, which is commonly used in medium and small span highway bridges, is taken as the research object, and the stress mechanism of continuous deck structure under load is analyzed according to the phenomenon that the continuous structure of bridge deck is prone to crack in the course of using. An analytical expression of the stress is derived. A simple supported hollow slab bridge with two spans continuous deck is established by using finite element analysis software. The stress of concrete and reinforcement continuously constructed on the deck under eight working conditions is analyzed with linear elasticity. The material nonlinearity of cracking in the upper edge is analyzed, the stress of steel bar in the pavement after cracking is analyzed and the crack width is estimated. Secondly, on the basis of considering the vehicle-bridge coupling vibration, the dynamic characteristics of this kind of bridge are analyzed, and the deflection time history curve and the moment history curve at the continuous joint of the simply supported plate bridge and the common simply supported plate bridge with continuous deck are given. The dynamic magnification factor of deflection in span and the dynamic magnification factor of bending moment at continuous joint are calculated. Finally, combined with the static and dynamic analysis results, the corresponding improvement measures are put forward by using the derived analytical formula of the continuous section stress of the bridge deck. The results show that the concrete stress at the upper and lower edge of the continuous structure of the bridge deck under load exceeds its ultimate tensile strength, and the vehicle-bridge coupling vibration is also unfavorable to the crack development of the concrete in the continuous joint. Using low elastic modulus material or sticking steel plate can improve the continuous force and crack propagation of bridge deck, and the method of using carbon fiber sheet and continuous section of bridge deck tensioning prestress is not effective. The results can be used as reference for evaluation and application of continuous simply supported bridge.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U443.31;U445.7
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，本文编号：2298438
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