新型销接钢筋铰缝弯剪复合作用下传力性能

为了研究铺装层厚度和销接钢筋铰缝对空心板桥铰缝传力性能的影响规律,通过改变桥面铺装层厚度和铰缝的配筋形式,设计了2组共4个梁式铰缝试件。进行了弯剪复合作用下结构开裂荷载、通缝荷载和极限荷载测试,与不带铺装层铰缝结构相比,传统结构加铺装层后分别提高了7.7%、114.3%和25.9%,新型销接钢筋铰缝结构加铺装层后分别提高了9.8%、61.3%和58%;与传统铰缝结构相比,新型销接钢筋与铺装层组合使用分别提高了28.6%、66.7%和88.2%,单独使用新型销接钢筋铰缝结构分别提高了26.2%、121.4%和50%。弯剪荷载作用下,加载侧与铰缝间荷载传递,在铰缝界面开裂前依靠界面黏结力,界面开裂后依靠界面黏结力和抗拉钢筋,界面裂缝贯通后,依靠抗拉钢筋传递荷载;铰缝与非加载侧自始至终通过界面黏结力实现荷载传递,新型销接钢筋铰缝多重横向受力钢筋自下而上依次破坏,破坏过程呈现出一定的延性。

Force transmission of the hinge joint with the new pin-connected rebar of the hollow slab bridge under bending-shear load

To study the influence of pavement thickness and the new pin-connected rebar on the force transmission of the hinge joint of the hollow slab bridge, two sets with a total of four hinge connected beam specimens with different pavement thickness and hinge reinforcement form are designed. The cracking load, joint load and ultimate load tests have been carried out with bending-shear load. Compared with the hinge jointed structure without pavement layer, after adding the pavement layer, the cracking capacity, joint capacity and ultimate capacity of traditional structure have increased by 7.7%, 114.3% and 25.9% respectively, and those of the structure with the new pin-connected rebar have increased by 9.8%, 61.3% and 58%. Compared with the traditional hinge jointed structure, the capacities of the structure with both the new pin-connected rebar and the pavement layer increase by 28.6%, 66.7% and 88.2%, and the loads of the structures with only the new pin- connected rebar increased by 26.2%, 121.4% and 50%. Under the action of bending and shear load, the load transfer between of loaded side and the hinge joint depends only on the interface bonding force before the joint interface cracks; after the interface cracks, it depends on both the interface bonding force and the tension force of the reinforcement; and after the crack penetrates, it depends only on the tension force of the reinforcement. However, the load transfer between the non-loaded side and the joint depends only on the interface bonding force at all cracking stages. The new pin-connected rebar under multiple transverse loads, fails sequentially from bottom to top, and the failure process shows a certain degree of ductility.