Reliability Appraisal And Maintenance & Strengthening Strategy Of Existing Reinforced Concrete Frame Strcuture

This paper aims at the weakness and shortcoming of the theory on the reliability appraisal of existing stucture, introduces the concept that is called "force transmitted tree", and then applies the theory of multilevel fuzzy assessment to establish the relability appraisal model of existing structure, at the same time, employs the approach FAHP to determin the weight of index. A case is used to prove that the application of multilevel fuzzy assessment is feasible and of great practical value.Based on the discussion and analysis of the prensent theory of decision-making on structrue strengthening, the technique of fuzzy multiattribute decision-making is employed to establish the decision-making model of maintenance and strengthening of existing congstruction structure by considering the feature of the decision theory applied in existing structure. Compared with former decision-theoretic approach, this model is of strict foudation of theory and can combine the fuzzy index with accurate index of strengthening approach to operate to get the value of fuzzy avail, and also synthesizes the experience of experts and the fruit of theoretical research. Besides these, this model can be calculated by computer program and applied to practise easily, thus provides theoretical support for computer-aided decision-making system of maintenace and strengthening of existing construction structure. A case shows that the decision-making technique is credible and can be used to guide the decision-making of maintenace and strengthening of existing construction structure.The last part of this paper defines a critical member that affects the durability of existing structure, introduces the prediction methodology in which the surplus life of existing structure is determined by its critical member. Firstly, based on the structure pushover analysis and the detection result of members, a method, which looks for the critical member, is presented, then uses the prediction method of member surplus life based on dynamic reliability to determine the residual service life of existing structure. A case about a deteriorating workshop building proves that this method is effective tohelp the reliability appraisal and the identification of the maintenance and strengthening strategy of deteriorating structure...