钢筋混凝土分体柱理论与技术
THEORY AND TECHNOLOGY OF SPLIT REINFORCED CONCRETE COLUMNS
-
摘要: 在钢筋混凝土高层建筑结构中,由于柱轴压比的限制,框架柱的截面大、剪跨比小,在结构底部经常形成短柱甚至超短柱,短柱延性差,地震时易发生脆性剪切破坏而导致结构破坏甚至倒塌。钢筋混凝土分体柱技术就是采用隔板将矩形短柱截面劈分成2根或4根独立配筋的等截面单元柱,使短柱的剪跨比扩大一倍,直接变短柱为“长”柱。系统地介绍了钢筋混凝土分体柱理论与技术,包括分体柱的承载力和抗震性能、分体柱框架梁柱节点的抗震性能、分体柱框架的抗震性能以及设计和施工建议等理论、试验和应用研究。创新成果表明,分体柱会使柱的抗弯承载力稍有降低,抗剪承载力保持不变,而变形能力和延性显著提高,且柱的破坏形态由剪切型转变为弯曲型,实现变短柱为“长”柱,从而从根本上改善了钢筋混凝土短柱的抗震性能,提高了钢筋混凝土高层建筑结构的抗震安全性。研究成果获得了天津市科学技术进步一等奖、国家发明专利和国家实用新型专利,为钢筋混凝土分体柱技术在钢筋混凝土高层建筑结构抗震设计中的应用提供了可靠的理论基础、试验依据和工程实例。Abstract: In reinforced concrete tall building structures, the sections of the frame columns are larger and their shear-span ratios are smaller due to the limitation of the axial-compression ratio of the columns. Some short and even ultra short columns at the bottom floors of the structures are prone to brittle shear failure which may result in damage and even collapse of the structures because of their poor ductility during earthquakes. A technique to split a rectangular short column into 2 or 4 elemental columns with the same section and individual reinforcement is introduced. As a result, the shear-span ratio of the short column is doubled and the short column is changed into “long” columns directly. In this paper, the split reinforced concrete column technique is systematically investigated, which covers the theoretical, experimental and applicable studies of the bearing capacity and seismic behavior of split columns, the seismic behavior of the beam-column joints of the frame with split columns, and the integral seismic behavior and main suggestion for design and construction of the frame with split columns. It is shown that the split column reduces the bearing capacity of the column to bending slightly, keeps the bearing capacity to shearing unchanged, but increases the deformation capacity and ductility of the column remarkably. In addition, the failure pattern of the column is changed from the shearing pattern to the flexural pattern, improving the seismic behavior of the reinforced concrete short columns and the seismic safety of the reinforced concrete tall building structures significantly. The present research work has gained a first-class award of the Tianjin Municipal Science and Technology Achievements, a Chinese patent for invention and a Chinese patent for utility model. It provides reliable theoretical foundation, experimental basis and engineering illustration for the application of the technology of split reinforced concrete column in the aseismic design for reinforced concrete tall building structures.