考虑桥面板开裂的连续桥面简支梁桥力学性能研究

Research on Mechanical Properties of Simple Supported Girder Bridge with Continuous Deck Considering Crack of Slab

连续桥面简支梁桥可以减少桥梁伸缩缝、降低冲击荷载、提高行车舒适性.但该类桥梁的桥面连续段容易开裂,且开裂分析理论尚不完善,阻碍了相关的设计与施工优化.因此,针对连续桥面多跨简支梁桥,建立了一种带边界转动弹簧的简支梁模型,提出了考虑桥面板开裂的力学性能分析方法,探讨了荷载作用下桥梁整体与桥面连续段局部的工作性能.实例分析表明,汽车荷载作用下桥面连续段上部混凝土存在开裂,下部混凝土容易压碎,需要通过加大连续段长度等构造措施加以改进;连续段混凝土的开裂对主梁的受力性能影响不大.

Application of the simple supported girder bridge with continuous deck can decrease expansion joints, reduce the impact load and improve riding comfort. But the continuous deck of this kind of bridge is easy to be cracked, and the analytical theory is incomplete to examine this problem. It hinders the improvement of design and bridge construction. Therefore, a simple supported beam model with boundary rotational spring is built to simulate simple supported girder bridge with continuous deck. An analytical method is presented which considers the crack of continuous slab for the mechanical behavior, the performance of the whole bridge and the link slab under load as well. The analysis shows that the concrete is cracked on the top of link slab when the bridge is under vehicle load, and is easily crushed on the bottom, too. It is found that the crack of the link slab concrete will not noticeably affect the mechanical behavior of the main girder of bridge.