The Evaluation Of Anti-Seismic Capability Of Reinforced Concrete Structures

China is one of the countries suffered the worst seismic hazard in the world, therefore, much attention is paid that whether the newly-built and existing construction has the sufficient seismic resistance capacity, reinforced concrete structure is the principal pattern of building construction in our country, The seismic resistance capacity is the important index of safeguarding the lives and property of the people, the basis standard of the former design of the reinforced concrete structure in great quantities is too low, in addition of the damage of durability and structure, it has become a very important research project how to evaluate the seismic resistance capacity of building construction. It stands in need of developing one method for evaluating quantitatively the seismic resistance capacity of building construction so that the construction lack of seismic resistance capacity can be reinforced or even removed. The purpose of this paper is to provide one quantitative method for evaluating the seismic resistance capacity of reinforced concrete building construction by combining our country's latest design general rule of anti-seismic behavior of construction project, the current design code of building aseismicity, concrete structure design code and earthquake-resistant fortifying standard.The content of the paper mainly comprises several aspects hereinafter:1. According to our country's latest design general rules of anti-seismic behavior of construction project, the current design code of building aseismicity, concrete structure design code and earthquake-resistant fortifying standard, the paper uses the idea of anti-seismic evaluation structural strength and ductility for reference to establish the anti-seismic evaluation system of reinforced concrete structure based on combining the anti-seismic idea of strength and ductility and China criterion. The expression of evaluating results refers to that of the seismic resistance capacity ratio of American ATC3-06, the seismic resistance capacity of construction is expressed by dilapidation ground motion acceleration Ac.The paper adopts ETABS soft not only in calculating the inner force of elastic seism, but also in calculating the strength and ductility of reinforced concrete unit according to the size of the practical components of building construction and constructional reinforcement, meanwhile, the paper also studies the quantitative method for evaluating the seismic resistance capacity of reinforced concrete frame structure and shear wall frame structure. After seismic resistance capacity of upper and lower half floors of each story, i.e. the ground motion acceleration undergone when ruptured, is calculated, the comparison made between Ac and the target seismic acceleration can judge whether the seismic resistance capacity of all stories of building construction meet the demandWhen the paper evaluates the seismic resistance capacity of the existing construction, the residual useful life of building construction, the characteristic subarea of seismic risk and the transcendental probability of different fortifying levels have to be considered in this paper according to our country's latest design general rules of anti-seismic behavior of construction project, in order to make the ground motion acceleration standard using for evaluating whether the existing building construction meet the anti-seismic fortifying demand more reasonable.2. The seismic resistance capacity evaluation of reinforced concrete structure cell can be finished on the basis of the idea of anti-seismic evaluation strength and ductility and of the theory of reinforced concrete structure, and the analysis system of seismic upgrading of vulnerable stories and vulnerable units are also established. The analysis about vulnerable characteristic of reinforced concrete structure unit is discussed in the paper after the seismic resistance capacity evaluation of reinforced concrete structure has been finished. According to the bearing capacity of reinforced concrete unit calculated, the elasticity limit and plasticity limit of evaluating unit, and by considering the stress of unit under target seismic action , and considering the stress state of evaluation unit under the target seismic action, whether the unit is vulnerable can be judged. The rationality of story upgrading and unit upgrading can be proved when the paper provides yardstick of vulnerable story and vulnerable unit, and defines the reasonable target and order of upgrading of construction unit, and provides the simple evaluation method of construction after upgrading,.3. The VC++ language can be used to compile analysis computing software program. The computing program includes three Module Blocks, MB pre-processing, MB seismic resistance capacity evaluation and MB both element analysis and reinforcement of vulnerable story and vulnerable cell, these three modules are mutual independent as well as constitute a organic whole. The MB anti-seismic evaluation evaluates quantitatively seismic resistance capacity of reinforced concrete frame structure and shear wall frame structure, MB both element analysis and reinforcement of vulnerable story and vulnerable cell implements the analytical judge of vulnerable structural story and vulnerable structural cell, and analytical evaluation of seismic resistance capacity of structure after reinforcement. According to the programs compiled basing on theory of anti-seismic evaluation and analysis of reinforced concrete structure, the paper not only evaluates quantitatively the seismic resistance capacity of building construction but also finds out the cause of the scarce seismic resistance capacity from the evaluation results. The evaluation computing software interface is friendly, easy to operate and the soft also provides better prospects for the popularization of evaluation method.4. The simplified capacity spectrum method suitable for seismic resistant evaluation of the existing reinforced concrete structure is explored by adopting the idea of seismic resistance capacity evaluation of capacity spectrum on the basis of behavior in analyzing the nonlinearity static of the architectural construction. The method discussed in this paper judges whether seismic resistance capacity of existing buildings meets the demand by basing on a comparison between seismic demand and corresponding seismic resistance capacity of the existing building calculated by capacity spectrum but not on whether demand spectrum and capacity spectrum have intersection point. This method could show the ductility development of construction under the seismic action. And show the seismic resistance capacity of buildings under different ductility. Simultaneously the calculation software program compiled with VC++ language. Is used for implementing the seismic resistance evaluation of simplified capacity spectrum method for the existing reinforced concrete structure. The program provides convenience for the practical application of evaluation method,5. Guangxi Control Center Building of seism prevention & Disaster relief, Guangxi TV & Radio Building (Nanning) and the School Building of Nanning Xinwu Primary School have been taken for instance for the evaluation method of seismic resistance capacity of reinforced concrete structure based on strength and ductility, these examples verified the practicability and rationality of calculation program compiled and of theoretical method offered in the paper, simultaneously the evaluation result was analyzed.The paper also adopts the simplified capacity spectrum method in analyzing the structure in the project calculation example of the School Building of Nanning Xinwu Primary School, by comparing the results from both methods, it is found that the evaluation result based on strength and ductility accords with that based on simplified capacity spectrum method, and the evaluation result fitted reality of seismic resistance capability of building construction. Therefore, for the seismic resistance capability evaluation of the existing building construction, the method based on strength and ductility and the simplified capacity spectrum method are effective evaluation methodsThe paper, in addition, makes the analysis of vulnerable characteristic and upgrading example of the construction project of the School Building of Nanning Xinwu Primary School, the paper also evaluates the seismic resistance capability of building construction before and after upgrading by adopting capacity spectrum method, the validity and rationality of the theory of upgrading and evaluation from this paper is verified through contrast and analysis.