Study On Seismic Capacity Of High-rise Reinforced Concrete Frame Structures

In2004, the China State Council announces the medium to long-termobjective that China should have the ability to resist the M6.0earthquake andthe seismic basic intensity action, and the ability reducing earthquake disasterof metropolis-medium city and developed regions aim at the level ofmoderately developed country in2020.The seismic capacity directly relates tothe the ability reducing earthquake disaster.This paper focuses on the seismiccapacity of a single building,which consists of the relative seismic capacityand the absolute seismic capacity. Bases on the performance-based seismicdesign, summarizing the methods of evaluating the seismic capacity, thispaper investigates the quantitative method of assessing the seismic capacity ofhigh-rise reinforced concrete frame structures, and proposes the means ofquantitatively assessing the relative seismic capacity and the absolute seismiccapacity respectively. In additional, the practicability of the means is verifiedby two reinforced concrete frame models of9-storery and15-storery. Thechief research work is summarized as below.1. Referring many papers involving performance-based seismic design theory,seismic capacity evaluation and seismic damage estimation, the authorsummarizes the common methods of evaluating seismic capacity andimproves the improved capacity spectrum method proposed byChopra.Besides, building two reinforced concrete frame models of9-storeryand15-storery by OpenSees,analyzing the data by Matlab,bilinearing thecapacity spectrum,drawing the demand spectrum,and calculating the targetdisplacement also belong to the research work in this paper.2. The method of assessing the absolute seismic capacity quantitatively for thehigh-rise reinforced concrete frame structures is proposed, which quotes thehorizontal acceration of the ground to assess the absolute seismic capacityquantitatively.On the basis of the concept and the code for seismic design forbuildings, the assessing method backsteps the horizontal acceration of theground through the maximum base shear force, and the ground acceleration isthe performance index.3. The method of assessing the relative seismic capacity quantitatively for thehigh-rise reinforced concrete frame structures is proposed, which combinesthe modal pushover analysis and the improved capacity spectrum method toobtain the target displacement under the specific seismic action. The methodalso chooses the maximum inter-storey drift ratio as performance index, anddivides the relative seismic capacity into five grades, which can assess therelative capacity of the high-rise reinforced concrete frame structuresquantitatively.4. The another method of assessing the relative seismic capacity quantitativelyfor the high-rise reinforced concrete frame structures is proposed, whichquotes the damage index of Park-Ang damage model for reinforced concrete in order to assess the relative seismic capacity of the high-rise reinforcedconcrete frame structures. This paper introduces how to solve the parametersof the formula and the substance of the parameters, besides, the methodsimplifies the solving procedure. A parameter called performance index whichhas the same solving procedure but has the different physical significance isintroduced in the paper with the purpose of distinguishing capacity fromdamage. The method also divides the relative seismic capacity into five grades,which can assess the relative capacity of the high-rise reinforced concreteframe structures quantitatively.5. The practicability of the two means which involves the relative seismiccapacity and the absolute seismic capacity is verified by two reinforcedconcrete frame models of9-storery and15-storery.