The Study Of Multi-objective Intelligent Optimization In Highway Profile

The linear scheme of highway vertical profile directly influenced theconstruction cost. It had close relations with the traffic safety and driving comfort.At the same time, it also had significant effect to energy saving and consumptionreducing and the ecological environment along the highway. Therefore, when theengineers in various countries including China survey and design highways, theytake some sustainable development factors such as project cost, safety factors andenvironmental protection into account. The optimization theory and method abouthighway alignment were studied to alleviate the economic and social problems inhighway construction. Those studies could reduce environmental damage as much aspossible while insuring traffic safety. Based on the above problem, this articlestudied how to construct multi-objective optimization mathematical model ofhighway vertical profile, and studied the solving theory of the model including theirfeasibility and effectiveness. The main research contents and conclusions areas follows::(1) On the basis about the analysis of optimization theory of highway verticalprofile, the necessity of the multi-objective optimization of highway vertical profilewas discussed. The main factors limiting the multi-objective optimization ofhighway vertical profile were analyzed, especially in project and engineering costsin highway construction, the environment impact in the design of highway verticalprofile and the traffic safety in the design of highway vertical profile, etc. From theperspective of application, the theory and method about multi-objective optimizationwas summarized and concluded. The multi-objective optimization model based onfuzzy mathematics theory was put up.(2) Taking the engineering economy as the starting point, the objectivefunction of engineering quantity and engineering cost was established by takingengineering cost of cubic meter of earth and stone, retaining engineering cost, bridgeengineering cost, tunnel engineering cost and vehicle operation cost into account.(3) Based on fuzzy theory and taking the factors of ecological environment inhighway construction as the starting point, the impact to atmospheric environment,soil environment, biological environment, sound environment and water environmentin highway construction was analyzed. The fuzzy evaluation objective function ofecological environment in highway construction was established by analyzingexperts estimate method, weighted statistics method and frequency statistics method. (4) Though the analysis and discussion to the relation of the slope and trafficsafety, the relation of the slope length and traffic safety, the relation of vertical curveand traffic safety,the evaluation equation about the impact to traffic safety inhighway vertical profile design was put up as traffic safety objective function(5) According to three objective functions mentioned above and by studyingthe theory and method to solve the multi-objective problem of highway verticalprofile, the solving methods by using modern intelligent optimization algorithmwere established. By the analysis of the theory about genetic algorithm, the NSGA-â…¡genetic optimization method in the multi-objective optimization problem of highwayvertical profile was established. And then, the chromosome coding method, themethod to determine fitness function and the realization method of genetic operatorsin the multi-objective genetic optimization problem of highway vertical profile wereestablished. By the analysis of the theory and application about ant colony algorithm,the ant colony optimization method to solve the multi-objective optimizationproblem of highway vertical profile was also established. Then the method to set upthe initial ant colony, the method to looking for the optimal solution for ant colonyand the ant colony mobile strategy in the multi-objective optimization problem ofhighway vertical profile was also established. Through the computer simulation, thefeasibility and effectiveness of the solving method was proved.(6) The multi-objective intelligent optimization system in highway verticalprofile design was compiled, and then the system was proved feasible by the case ofthe engineering application. The same case was optimized by using themulti-objective genetic algorithm and the multi-objective ant colony algorithm. ThePareto solution sets of the multi-objective genetic algorithm and the multi-objectiveant colony algorithm in the case all were got, and then their optimal solutionsrecommended also were got for policymakers to choose. In order to get the moreeffective solution, the system merged the Pareto solution set of the multi-objectivegenetic algorithm and the Pareto solution set of the multi-objective ant colonyalgorithm, and then obtained final optimization results by using compromise methodor distance method.By analyzing and researching as well editing soft program, the multi-objectiveintelligent optimization in highway vertical profile was realized. It could effectivelyreduce the construction cost. It could reduce the ecological environment destructionas far as possible. It also could effectively reduce the traffic accident from technicalpoint of view in highway construction. Traffic safety, comfort and economy wereimproved and the sustainable development in highway construction was realized.