Research On The Optimization For Strengthening Design Of R.C.Structures

The problem of optimization for strengthening design of R.C. structures which aims at overcoming the shortcomings of traditional design method and improving the effectiveness and efficiency of strengthening design is presented in this paper.Optimization of strengthening scheme of R.C. structures is firstly discussed. After the analysis of the common strengthening method ,some referential opinion of initial scheme is presented. Multi-hierarchical comprehensive evaluation index system is proposed on the basis of the systematically study of the goal and influential factors of optimization of strengthening scheme. Applying the theory of fuzzy mathematics, the evaluation index system is processed and multi-hierarchical fuzzy comprehensive evaluation and decision model is proposed. Besides, the optimization method is introduced in detail with a example.Optimum design of parameters of strengthening scheme is discussed with strengthening with a reinforced concrete jacket as the object Mathematical models based on the lowest material price are constructed and sequence unconstrained minimization technique is adopted to solve the problem. Results got through optimum design are better than those got through conventional design.At last, the beam strengthened with a reinforced jacket on the tension side is analyzed nonlinearly for reference to optimum design. The distributions of stresses and strains on the section of strengthened beam are analyzed. The different formulas for the calculation of internal forces of section are deduced according to the different development stages of strain and a flow diagram for the calculation is established. With the program based on the diagram, the internal forces and some relevant parameters of the strengthened beams are calculated and the main factors which affect the ultimate bearing capacity of the beams are discussed.