山区铁路桥隧工程关键节材要素均衡优化OA北大核心CSTPCD

In order to improve the material-saving performance of mountain railway within the affordable range,a double-objective equilibrium optimization of key material-saving elements based on NSGA-Ⅱ was proposed.Firstly,taking the five key material-saving elements of bridge-tunnel engineering as decision variables,including section over-excavation,shotcrete type selection,surrounding rock deformation reservation,pile foundation reaming and pile head over-sealing,and taking the maximum CO2 emission reduction and the minimum added value of construction cost as the optimization objectives,the equilibrium optimization model of key material-saving elements of mountain railway bridge-tunnel engineering was constructed.Secondly,the Pareto equilibrium solution set was obtained by non-dominated sorting genetic algorithm with elite strategy(NSGA-Ⅱ).Thirdly,comprehensive weighting method of subjective and objective elements combination and TOPSIS method were used to make scientific decisions on the Pareto equilibrium solution set.The optimal combination of key material saving factors considering decision maker's preference was obtained.The influence of decision makers'preference on the optimal combination was analyzed.Finally,taking a section of a mountain railway project as an example,the scientificity and applicability of the method were systematically verified.The results show that compared with the previous optimization,the optimal combination can achieve the CO2 emission reduction of 12.622×104 tons,the corresponding construction cost increases by 24.833×104 yuan,and the optimization efficiency reaches 50.826%.