结合面底部设开孔钢板的铰接空心板力学性能

发布时间：2019-01-23 08:22

【摘要】：针对现有铰接空心板桥的薄弱部位——铰缝,提出一种在空心板与铰缝结合面底部设开孔钢板的空心板构造,通过开孔钢板改变结合面裂缝开展的路径,达到延缓空心板与铰缝结合面通缝形成的目的,并进行了8m跨径的铰接空心板足尺模型试验。在试验和非线性有限元分析的基础上,与结合面底部带钢筋的铰接空心板试验进行了对比。分析结果表明:当试验荷载为100kN(1.43倍车辆荷载)时,空心板跨中出现横向裂缝,空心板梁整体刚度降低,空心板受力状态由弹性阶段进入弹塑性阶段;在试验荷载加至300kN(4.29倍车辆荷载)为止的整个加载过程,未观察到空心板与铰缝结合面底部出现裂缝;当结合面底部设门式钢筋时,裂缝沿结合面从下向上扩展,最终形成通缝,然而,当结合面底部设开孔钢板后,铰缝沿结合面开裂至开孔钢板下方后,裂缝的扩展需要绕过开孔钢板,使得开孔钢板下方铰缝混凝土开裂后,再沿开孔钢板上方结合面向上扩展,形成通缝;铰缝开裂荷载由结合面设置钢筋的69kN(0.99倍车辆荷载)提高到314kN(4.49倍车辆荷载),提高了3.50倍;铰缝形成通缝时的荷载由结合面设置钢筋的199kN(2.84倍车辆荷载)提高到489kN(6.99倍车辆荷载),提高了4.51倍。可见,在结合面底部设开孔钢板后,铰缝裂缝开展路径发生变化,延缓了空心板与铰缝结合面的开裂。
[Abstract]:In view of the weak position of the existing hinged hollow slab bridge, the hinged joint, a kind of hollow slab structure with perforated steel plate at the bottom of the joint surface between the hollow slab and the hinge joint, is proposed, and the crack path of the joint surface is changed by the perforated steel plate. In order to delay the formation of joint between hollow slab and hinge joint, the full-scale model test of 8m span hinged hollow plate was carried out. On the basis of experiment and nonlinear finite element analysis, the experiment of hinged hollow slab with reinforcing bar at the bottom of joint surface is compared. The results show that when the test load is 100kN (1.43 times vehicle load), transverse cracks appear in the hollow slab span, the overall stiffness of the hollow slab beam decreases, and the stress state of the hollow slab moves from elastic stage to elastic-plastic stage. During the whole loading process when the test load was added to 300kN (4.29 times vehicle load), no cracks were observed at the bottom of the joint plane between the hollow slab and the hinge joint. When the gate steel bar is arranged at the bottom of the bonding surface, the crack extends from the bottom of the joint surface and forms a through joint. However, when the bottom of the joint surface is set with a perforated steel plate, the hinge joint cracks along the joint surface to the bottom of the open hole plate. The crack propagation needs to circumvent the perforated steel plate, make the concrete crack under the perforated steel plate, and then expand along the top of the perforated steel plate to form the through joint. The cracking load of hinged joints was increased from 69kN (0.99 times vehicle load) to 314kN (4.49 times vehicle load), which increased 3.50 times. When the joint is formed, the load is increased from 199kN (2.84 times vehicle load) to 489kN (6.99 times vehicle load), which increases 4.51 times. It can be seen that the crack development path of the hinge joint changes after the opening plate is set at the bottom of the joint surface, which delays the cracking of the hollow slab and the joint surface.
【作者单位】：福州大学土木工程学院;长崎大学工学部;
【基金】：国家自然科学基金项目(51678154) 教育部新世纪优秀人才支持计划项目(NCET-13-0737) 河北省交通科技项目(Y-2014045)
【分类号】：U441

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