柱端弯矩增大系数对PC框架结构抗震性能影响的研究

发布时间：2018-04-26 01:15

本文选题：预应力混凝土框架 + 抗震性能　；参考：《湖南大学学报(自然科学版)》2014年11期

【摘要】：根据我国现行《预应力混凝土结构抗震设计规程》(JGJ 140-2004),以设防烈度为8度(0.2g)地区的多跨多层预应力混凝土框架结构柱端弯矩增大系数为研究对象,对其合理取值问题进行了探讨.在SAP2000与PERFORM-3D软件中,采用局部纤维铰梁单元,对6个PC平面框架建立了弹塑性分析模型,并对其进行了静力弹塑性分析(Pushover分析)与动力弹塑性时程分析.计算结果表明:按照现行规范设计的PC框架,基本上可以满足8度区罕遇地震作用下的抗震要求,但是结构在大震作用下形成的是以底层柱端出铰为主的梁柱铰屈服机制,对结构抗震不利;随着柱端弯矩增大系数的增加,结构的局部构件抗震性能以及屈服机制均有很大程度的改善,当边柱和中柱的柱端弯矩增大系数分别增加到2.0,1.8时,预应力混凝土框架结构能够实现对结构抗震有利的以梁出铰为主的梁柱铰屈服机制,甚至是梁铰屈服机制.因此,建议在进行预应力抗震技术规程的修订时,适当提高框架结构柱端弯矩增大系数的取值.
[Abstract]:According to the current Code for Seismic Design of Prestressed concrete structures in China (JGJ 140-2004), this paper studies the increasing coefficient of bending moment at the end of columns of multi-span and multi-story prestressed concrete frame structures in the area with a fortification intensity of 8 degrees or 0.2 g, and discusses the reasonable selection of its value. In the software of SAP2000 and PERFORM-3D, the elastic-plastic analysis model of six PC plane frames is established by using the local fiber hinged beam element, and the static elastic-plastic analysis and the dynamic elastic-plastic time-history analysis are carried out. The calculation results show that the PC frame designed according to the current code can basically meet the seismic requirements under the rare earthquake in the region of 8 degrees, but the yield mechanism of the Liang Zhu hinge with the end of the bottom column is formed under the action of the strong earthquake. The seismic behavior and yield mechanism of local members of the structure are improved to a great extent with the increase of the moment increasing coefficient at the end of the column, when the increasing coefficient of the moment at the end of the column is increased to 2.0 and 1.8, respectively. The prestressed concrete frame structure can realize the yield mechanism of Liang Zhu's hinge, even the yield mechanism of beam hinge, which is favorable to the earthquake resistance of the structure. Therefore, it is suggested that the increase coefficient of column end moment of frame structure should be increased properly when revising the technical code of prestressed earthquake resistance.
【作者单位】：华中科技大学土木工程与力学学院;中信建筑设计研究总院有限公司;
【基金】：国家自然科学基金资助项目(51278218)
【分类号】：TU378.4;TU352.11

【参考文献】