土木工程專業(yè)-外文翻譯-將玻璃鋼外套用于鋼筋混凝土框架結(jié)構(gòu)抗震加固的最優(yōu)設(shè)計(編輯修改稿)
2024-10-22 19:14 本頁面
【文章內(nèi)容簡介】 uilding is prevented during specified ground motions [3]. In addition, the cost of implementation is of great concern to both building owners and practicing engineers [4]. The overall seismic retrofit strategy for an RC frame must consider a number of key issues in an integrated manner。 these issues include the strengthening of beams, columns and beamcolumn joints to prevent brittle failure modes such as shear failure to bee critical using external FRP reinforcement or other appropriate methods。Once these brittle failure modes are suppressed, the seismic retrofit design to enable the frame to satisfy specific demands of an earthquake depends on the strength and ductility of the columns under bined axial pression and bending. Retrofit of the columns is one of the most widely used seismic upgrading approaches for RC frames，Improving the column behavior typically involves increasing its strength, ductility, stiffness or in most cases a bination of these parameters. Conventional retrofit measures for columns include RC overlays or steel jacketing. A more recent technique is the use of fiberreinforced polymer (FRP) jackets to confine columns [5] and [6]. In such jackets, the fibers are oriented only or predominantly in the hoop direction to confine the concrete so that both its pressive strength and ultimate pressive strain are significantly enhanced [5], [6] and [7]. Compared to conventional techniques, FRP jacketing is easier and quicker to implement, adds virtually no weight to the existing structure, has minimal aesthetic impact and is corrosionresistant. As a result, FRP jacketing has been found to be a more costeffective solution than conventional techniques in many situations and has thus been widely accepted [5], [6] and [8]. For the seismic retrofit of RC frames employing FRP confinement of RC columns, apart from the structural response of a retrofitted frame, an important issue is how to deploy the least amount of the FRP material to achieve the required upgrade in seismic performance. With these two issues in mind, this paper presents an optimization technique for the performancebased seismic FRP retrofit design of RC building frames. The thicknesses of FRP jackets in the columns are considered as the design variables, while the least total material cost (. costs associated with other aspects such as transportation are not included) of FRP and a uniform ductility demand are taken as design objectives of the inelastic drift design optimization process.2. Existing work on optimal performancedbased seismic designTraditional design approaches for seismic retrofit, similar to traditional approaches for seismic design of new structures, assume that structures respond elastically even to severe earthquakes [9]. Performancebased seismic design, which appears to be the future direction of seismic design codes, directly addresses inelastic deformations induced in structures by earthquakes [3], [9] and [10].In assessing the nonlinear seismic behavior of framed structures, pushover analysis has been increasingly accepted as part of the performancebased design procedure. Pushover analysis is a simplified, static, nonlinear procedure in which a predefined pattern of earthquake loads is applied incrementally to the structure until a plastic collapse mechanism is reached. This method of analysis generally adopts a lumpedplasticity approach that tracks the spreading of inelasticity through the formation of plast
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