Study Of Internal Structure Features Of Urban Road Network Based On Fractal Method

Whole function and service level of urban road network are directly affected by internal structure features of it,however,analysis and evaluation method applied in internal structure features of urban road network are not yet perfect at present.Although scale and connected efficiency of urban road network could be effectively characterized by road network technical indices in traditional road network evaluation method such as density,connectivity and grade level of road network,these indices could neither effectively represent local features of road network nor guide internal structure adjustment of it.Based on this,in order to get the method of analysis which could be effectively characterized internal structure features of road network as well be a guidance for optimization of internal structure features of road network,fractal theory is cited and applied to the analysis of internal structural characteristics of urban road network in this paper.First of all,in order to demonstrate the feasibility of fractal theory's application in urban road network,features as fractal self-similar and scale invariant in scale-free interval were introduced,and concrete embodiments of fractal characteristics of urban road network in the structure level partition and layout forms of urban road network are analyzed.Then,method of measuring fractal parameter of each level in urban road network is obtained by extending simplified method—Hausdorff used in measuring fractal parameters.Moreover,detailed discussion of the process to get fractal dimension is conducted and evaluation standard of corresponding indices is established after structure coordination index KDi and structural diversity index KRi are proposed based on fractal dimension Di(r)and connection depth Ri.In the thesis,evaluation indices system and corresponding evaluation standard of road network established based on fractal method are applied in the analysis and evaluation of urban road network planning scheme in Wangcheng district.According to the evaluation result,possible structural problems existing in the urban road network planning scheme was discovered and adjusted test scheme of planning is put forward after corresponding structure optimization measures are improved.Evaluation results of road network fractal method in the adjusted test scheme is better than that in original planning scheme,thus,feasibility ofevaluation method of road network based on fractal theory applying in guiding internal structure adjustment of road network is demonstrated.In this thesis,feasibility of fractal theory applying in internal structure features study of urban road network is discussed,indices system and evaluation standard of internal structure features analysis of road network based on fractal is established,and its rationality is proved take Wangcheng district as an example.The conclusion obtained could be taken as a reference for internal structure adjustment of urban road network.