端部损伤控制型RC带板梁抗震性能研究

Seismic performance on end damage control type of RC slab beams

楼板对梁端的加强作用是影响框架梁抗震性能的重要因素。合理有效的控制框架梁在地震作用下的损伤破坏机制,是提高其抗震性能的重要手段。文章基于损伤控制思想,设计并进行了端部损伤控制型钢筋混凝土带板梁试件的低周反复荷载试验,研究了各试件的破坏特征、滞回特性、骨架曲线、承载力和延性系数以及累积滞回耗能等抗震性能。结果表明:带板梁端部设置无粘结钢筋段后,于试件梁端和无粘结钢筋段上端形成多个集中耗能区域,试件承载后期变形能力增强;各损伤控制型带板梁端部承载力基本不变而延性明显改善,延性系数提高约32.1%~86.7%;带板梁端部外包薄钢板后塑性铰范围的增大,会使结构的累积耗能能力提高约65%~86%。

The strengthening effect of floor slab on the end of the beam is an important factor that affects the seismic performance of the frame beam. Reasonable and effective control of damage and failure mechanism of frame beam under earthquake is an important method to improve its seismic capacity. Based on the damage control concept,the low-cycle repeated loading test of the end damage controlled reinforced concrete slab-beam specimens was designed and carried out. The failure characteristics,hysteretic characteristics,skeleton curves,bearing capacity and ductility coefficient and cumulative hysteretic energy dissipation were studied through the test. The test results show that：After the unbonded steel section was set at the end of the slab beam,a number of concentrated energy dissipation areas have been formed at the upper part of the beam end and the unbonded steel section,and the deformation capacity of the specimen was enhanced at the later stage of loading; the bearing capacity of all damage control type specimens was basically unchanged while the ductility had improved significantly. The increase of the ductility coefficient was about 32. 1% ~ 86. 7%; the range of plastic hinges was increased,which was beneficial to enhance the energy dissipation capacity of the structure,and the cumulative hysteretic energy dissipation capacity improved about 65% ~ 86%.