【作者】 周明杰；

【导师】 郑刚；

【作者基本信息】 天津大学 ， 建筑工程技术与管理， 2010， 博士

【摘要】 混凝土异形柱结构由于其构件自身的特点,与普通混凝土结构有许多不同之处。在异形柱结构发展和应用的各个阶段,不同版本的设计规程对其材料、配筋构造、适用范围、轴压比等的规定也存在着差异。近几十年来,结构抗震加固技术得到了迅速的发展与推广,但是针对混凝土异形柱结构的相关研究还较少。为了研究混凝土异形柱的抗震加固方法,完善相应的加固技术,本文设计制作了23根混凝土异形柱(包括7根L形柱、7根T形柱、4根十字形柱和5根Z形柱),并采用粘贴钢板、粘贴碳纤维布以及二者复合加固三种方法对其中19根实施了加固。对23根异形柱分别进行了水平低周反复荷载作用下的试验研究,观察了各构件的破坏过程和破坏形态,得到了水平荷载-位移滞回曲线,考察了构件中的钢筋、钢板和碳纤维布的应变发展。试验结果表明,采用粘贴钢板加固时,其水平极限荷载可以提高40%以上,延性和抗震耗能能力没有明显改善;采用满包方式粘贴碳纤维布加固时,其水平极限荷载约提高30%~40%,正负两向延性系数平均值提高60%以上;采用复合加固时,以上两种加固方法所达到的加固效果均能够较好地实现。采用有限元分析的方法对混凝土异形柱和复合加固异形柱进行了水平荷载作用下的计算分析,计算结果与试验结果吻合较好。表明本文所建立的复合加固异形柱的计算模型及选取的本构关系合理,计算方法可靠,可进一步推广应用于复合加固混凝土异形柱的计算分析。在试验研究和有限元分析的基础上,探讨了复合加固异形柱的加固作用机理。碳纤维布条带包裹时,起到的作用类似于箍筋,可改善构件延性;碳纤维布满包时,除了起到类似箍筋的作用外,还可使混凝土抗压强度在横向约束的作用下有所提高,同时其抗拉强度在构件纵向发挥作用而直接参与受力。以此为依据,给出了工程轴方向复合加固异形柱的正截面承载力计算公式。本文的创新点主要有:首次提出并研制用于混凝土异形柱的粘贴钢板和碳纤维布复合加固方法;通过对复合加固后异形柱进行水平低周反复荷载作用下的抗震性能试验研究,考察加固后异形柱的破坏特征,分析其承载能力、延性和抗震耗能能力;在试验研究和有限元分析计算基础上,给出了实用的复合加固混凝土异形柱正截面承载力计算公式。更多还原

【Abstract】 Compared with ordinary RC structure, the one with special-shaped columns have many different characteristics because of the special section shape of its columns. During the each sdage of development and application, there are different design regulations in the standard of special-shaped columns structure with different versions, such as material selection, reinforcement construction, application scope, axial compression ratio, and so on. In the past few years, the structural seismic strengthening technology is developed and popularized rapidly. However, the related research on RC special-shaped columns structure is comparatively less.In order to study the seismic strengthening mathod of RC special-shaped column and perfect its technology, 23 RC special-shaped columns (7 of them adoped L-shaped sections, 7 of them adoped T-shaped sections, 4 of them adoped +-shaped sections and 5 of them adoped Z-shaped sections) are designed and producted. 19 of them are strenthened respectively by the mathods of bonding steel plate, sticking carbon fibre sheet and complex with the two.The experimental studies of 23 special-shaped columns bearing horizontal reversed cyclic loads are completed. The failure process and pattern of all members are observed. The hysteretic curves of horizontal load -displacement are measured. The strain development process of reinforced bars, steel plates and carbon fibre sheets are obtained. The test results indicate that: when the mathod of bonding steel plate is used, the horizontal ultimate load of special-shaped columns can be increaced more than 40%, the ductility and aseismic consumed energy behavior can not be improved obviously; when the mathod of sticking carbon fibre sheet is used, the horizontal ultimate load can be increaced about 30%-40%, the ductility factor average value of positive and negative improved more than 60%; when the mathod of complex strenthenment is used, the reforcement effects of two mathods can all be realized, and the way of carbon fibre sheet full wrapping is better than bands wrapping.The un-strenthened and complex strenthened RC special-shaped columns under horizontal load are calculated, using the mathod of finite element analysis. The calculation results are satisfactorily uniform with experement. So the calculation model and constitutive relation are reasonable, calculation mathod is dependable and can be spread and applicated ulteriorly. Based the test researches and finite element analysis, the mechanism of complex strenthenment on special-shaped columns is discused. The role of bands wrapping carbon fibre sheet is similar with hoop reinforcement, it can improve the ductility of column; the effects of full wrapping carbon fibre sheet, not only are same with bands wrapping, but also can increase concrete strength because of constraining its lateral deformation, and can directly increase normal section bearing capacity because of its vertical tensile strength. According to these study results, the normal section bearing capacity calculation formulas of complex strenthened spacial-shaped columns at the direction of engineering axis are given.This article innovation mainly has: Proposes for the first time and develops the strengthening mathod of bonding steel and CFRP, that is used by RC special-shaped columns; through the experimental study on seismic behavior of complux strengthened columns under horizontal reversed cyclic loads, the destruction characteristic is observed, the bearing capacity, ductility and earthquake resistance are analyzed; based the experimental study and finite element analysis, the practical formulas for bearing capacity of narmal section are presented.更多还原