Optimizing selection of bridge raft based on fuzzy matter element model and combination weighting

It’s a necessary selection to support the maneuver across Yangtze River by floating bridge constructed by portable steel bridge and civilian ships.It is a comprehensive index for the scheme of bridge raft,containing a variety of technical factors and uncertainties.The optimization is the selection in the constructing time,quantity of equipments and man power.Based on the calculation result of bridge rafts,an evaluating system is established,consisting of index of spacing between interior bays,raft length,truss numbers,operation difficulty and maximal bending stress.A fuzzy matter element model of optimizing selection of bridge rafts was built up by combining quantitative analysis with qualitative analysis.The method of combination weighting was used to calculate the value of weights index to reduce the subjective randomness.The sequence of schemes and the optimization result were gained finally based on euclid approach degree.The application result shows that it is simple and practical.