| Identifications of the subsequent service life on the building structure are studied according to the characteristics of the existing building structure. This is depended on our country’s actual situation that old building transforming, national major infrastructure construction and people’s livelihood construction interspersed embarking in our country. The effect of new standards to appraisal work, which takes statistical data as scientific reference, is explored to make the future more systematic, scientific, economic and reasonable. This research is based on sources of data in identify standards. Confusion in the actual appraisal work is solved, especially for the contradictions existing standard for reliability evaluation of building structures exist.Based on the reliability analysis theory and the adjusted characteristic values of an action, the new target reliability index is calculated using the JCSS method and Monte Carlo method. Moreover, the adjustment factors and mathematical statistics parameters corresponding to different design working lives are computed according to different probability distribution models of variable actions. Especially, in theoretical analysis, based on the least square method, the partial factors of safety for load and the coefficients for importance of structures were developed by using the method of enumeration in association with optimization search and the method of extremum theory respectively. The relative error increments of the single component are then solved before and after the adjustment of the data (e.g. characteristic values). As for practical applications, the different coefficients for importance of structures corresponding to different levels of safety and design working lives under various situations are obtained when the partial safety factor for load and the partial safety factor for resistance meet the requirements of the current standard. Finally, the application envelops of different coefficients for importance of structures are analyzed for the future structure design.Based on the principle of structures ultimate classification, the coefficients for ap praisal identification of different subsequent service lives are calculated for existing st ructures and new structures respectively. Firstly, the resistance statistical parameters a re obtained according to different mathematical models of resistance for existing struc tures and new structures. Secondly, the coefficients for appraisal identification under t he circumstance of design reference period are solved before and after the adjustment of characteristic values of load. Thirdly, the coefficients for appraisal identification w hich meet the requirements of the current standard are computed corresponding to the adjustment factors and mathematical statistics parameters of different subsequent serv ice lives.Finally, safety margin of the coefficients for appraisal identification are achie ved by comparison when considering the resistance attenuation, which is analyzed for the future practical identification project. |
