Research And Development Of Highway Alignment Intelligent Selection And Decision Support System

Highway alignment selection is a multi-objective decision making that should consider the environmental protection, economic, security, traffic quality and function of many factors and objectives, which are sometimes contradictory and conflict. How to reconcile the relationship among these goals and seek the best alignment are important issues that puzzle highway workers for a long time. Limited by the design tools and computational models, the traditional highway design method is difficult to coordinate multi-objective relationship. It exist such defects as stick expert experience, subjectivity, over-emphasis on one objective while ignoring others and so on. In order to solve these issues, combining the development trend of computer technology and mathematics technology, Highway Alignment Intelligent Selection base on Multi-objective and Decision Support System is studied.Based on the deep analysis of the method of highway alignment selection, alignment evaluation and design system, the idea of highway alignment intelligent selection base on multi-objective and decision-making is put forward. By analyzing the connotation of highway alignment selection, the process model of alignment selection is established, the definition of highway alignment intelligent selection base on multi-objective is defined, and the highway selection and decision-making are described. Combining features of various stages for alignment selection, the framework of system is constructed based on current development of highway design system and application status. This paper plans the framework of system which is that alignment intelligent optimization based on multi-objective as core, multi-attribute intelligent decision making as the keystone, attribute analysis and calculation are researched as assistant. The data requirements and functional requirements of the system are detail analyzed.Aiming at the massive geographic data, attribute information, as well as alignment data and multi-objective decision-making and other characteristics of highway alignment selection, the Optimization method based on GIS and multi-objective Genetic Algorithm is proposed. The optimization models for horizontal and vertical alignment and multi-objective optimization are established. The method of programming coding genes and initial alignment are researched. And the functions of economic, safety and environmental are established to solve the problem of quantizing the safety and environmental objectives in the stage of highway alignment generation and evaluation. Considering the characteristics of horizontal and vertical alignment, the genetic-algorithm formulations are designed. The traditional genetic algorithm optimization processes is optimized to construct a multi-objective genetic algorithm program flow to suit highway alignment features. Finally, the non-inferior solution set is recommended as the initial alignment for designer to solve the key highway alignment automation technology, which can improve the pace of highway alignment intelligent selection.Based on the analysis of relationship between highway and geology, hydrology, topography and other environmental information, the data mining method is proposed for space environment and alignment information. The expression patterns are established for computer processing, which is suitable to alignment optimization model. The rules of design standards, basic theory, expertise and evaluation are constructed, and the control mechanisms and model library are also established.By deeply analysis of the features to multi-attribute decision making for highway alignment schemes, the analysis method and calculation method of GIS-based life cycle cost are proposed. By deeply research on the impact of environmental and safety on the alignment scheme, GIS-based environmental evaluation and highway alignment's safety evaluation are proposed. And then, the models are established to statistic and commutate attributes'value of economic, environmental and safety.Combining the different preference information, this paper offers multi-attribute decision making based on information entropy for no preference information problems, multi-attribute decision making based on alternative achievement scale and alternative comprehensive scale for some preference problems, multi-attribute decision making based on linear goal programming model for the problems which preference information is completely known. The conditions of application for various decision-making methods and detailed steps are illustrated to provide technical support for achieving highway alignment intelligent decision-making.With the theory and method reviewed in the paper, Arc GIS is Secondary developed. And with the framework of Visual Basic.net, the highway alignment intelligent selection and decision support system is developed which has the functions of highway alignment optimization, economic analysis, safety evaluation, evaluation of environmental effects and multi attribute decision making for alignment schemes. The system improves the level and depth of design, and provides a technical reference to the existing system for its improvement and perfection.