Application Of Performance-based Seismic Reinforcement Design

In the past 100 years,there's more large earthquakes token place all over the world,especially in recent decades.Seismic data shows there have been 24 earthquakes over M7.0 since July 2009 and the globe seismicity level has entered a period of active stage.The major economic damage loss caused by the massive earthquake has been more and more serious and much far beyond the expectations of community can afford since 1990.China is an earthquake-prone country, and the damage caused by earthquake is rather serious. The current criterion for anti-seismic design of buildings can effectively avoid large-scale casualties in the earthquakes,but it does not work well in the control of losing economic assets.Due to various reasons,there are a large number of buildings which cannot meet the anti-seismic standards in our country. Civil Engineering is the main carrier of earthquake damage and the main target of disaster prevention and mitigation. Therefore,it is of great significance to reinforce the architectural design and improve the anti-seismic criterion in reducing earthquake damage and socio-economic losses.The anti-seismic design theory based on performance/displacement is the mainstream of the 21st century's seismic design development. It is grounded on the existing standard design method,transforming a single seismic fortification system into a multi-index and multi-level anti-seismic fortification system.According to engineering practice and the requirements of owners,the anti-seismic fortification goal would be determined reasonably and flexibly. Applying this idea to the seismic reinforcement of building structures is truly forward-looking and innovative,which will bring enormous social economic profits as well as broad research prospects.The ideas of architectural seismic design as well as the history and current theoretical situation of architectural seismic reinforcement techniques in China are introduced.The basic ideas and implementation methods of performance-based theory are summarized.All these provide a theoretical foundation to apply this idea to the seismic reinforcement field.The theory of general building structures anti-seismic and reinforcement method and design process based on performance theory is established by researching and analyzing the seismic reinforcement process of the transfinite high-rise building---Association of Southeast Asian Nations Building.The theory of general building structures anti-seismic and reinforcement method and design process based on performance theory is established by researching and analyzing the seismic reinforcement process of the transfinite high-rise building---Association of Southeast Asian Nations Building.First, engineering case is anti-seismic analyzed in original structure state,and engineering analytical procedure of reinforcement is defined by owners' realistic demands and actual engineering situation as well as technological measure of reinforcement. Then building anti-seismic performance level based on performance design theory is defined:not yield in the intermediate earthquakes.Performance-based seismic retrofit design can be divided into two sections:The first stage:Building model of original structure is established based on PKPM.In calculation module of SATWE,checking the button of "not yield in the intermediate earthquakes" without adjusting anti-seismic inner force and just inputting material standard value,then structure response in the intermediate earthquake level under existing ratio of reinforcement is worked out. After examining structure stress of shear wall under performance target, it's found that the bearing capacity is inadequate.But it can be satisfied by adding simulation supports in 1st floor. Performance displacement guideposts based on performance anti-seismic reinforcement can be determined by comparison of two kinds of interlamination displacements.The second stage:establishing original structure model based on MIDAS, making dynamic time-history analysis by inputting earthquake waves and then structure response in the intermediate earthquake level under existing ratio of reinforcement is worked out. Pilot calculations of dynamic time-history analysis are worked out after setting multiform damper operating modes in 1st floor of model and this optimum design process is directed by performance displacement guideposts.Performance reinforcement design level based on existing ratio of reinforcement:not yield in the intermediate earthquakes,can be achieved through conversion by displacement and bearing capacity.Some conclusions have been concluded as fellows through analytical study of anti-seismic reinforcement design engineering based on performance theory:1)Performance theory can be applied to anti-seismic reinforcement design of existing structures (especially the transfinite/high-rise building). Performance-based anti-seismic protected level can be determined after summing up owners' realistic demands and actual engineering situation,and building's structure response under earthquake can be controlled effectively by using traditional and new type reinforcement technology (especially energy dissipation system).Then building can be sure to appear expected failure shape while structure using function is extending and lose of lives and property is reducing.2) Analyzing methods and protected targets of performance-based anti-seismic retrofit should be selected by actual engineering situation smartly and rationally.3)This paper used PKPM to determine the structure reflects encountering seismic fortification level in the existing reinforcement conditions.The main method is using additional simulation to determine the displacement indicators within performance objectives.We use MIDAS/Gen to make anti-seismic reinforcing design within performance displacement index, set damper, and reduce the seismic load so as to achieve performance targets.Then this can reinforce anti-seismic ability and improve seismic performance of the structure. This method can be called "displacement---capacity method" for short, which is with original thinking and is relatively a simple control method.This will have guidance to the future reinforcing design research.4) The "displacement---capacity method" determines the anti-seismic reinforcing displacement control indicators in the existing capacity by PKPM firstly, and then uses the method which can meet the bearing capacity to achieve the displacement indicators.This method is more suitable for anti-seismic reinforcement analysis in the following situations:reinforcement design time is approaching deadlines;software and hardware design cannot satisfy the conventional performance.The method is simple to use,easy to operate and control for general designer, while strengthening design precision can fully meet of anti-seismic design requirements.5)Using performance-based theory of "displacement---capacity method" in anti-seismic reinforcement dezign cannot reduce only seismic force significantly, but also reduce reinforcement quantities of structure and componets as well as damage to the original structure made by reinforcement measures effectively. It is with certain economic benefits.