Study On Boundary Roads Of Former British,French And Japanese Concessions In Tianjin

Tianjin is the city with the largest number of concessions in modern China.In the process of planning and construction,a series of administrative divisions or staged construction areas were formed in the former nine countries concession area.The boundary roads(construction boundary)between these areas are the road network characteristic that distinguishes Tianjin from other colonial cities.At the same time,influenced by the diversified planning ideas and system background of the concession countries,modern Tianjin formed a collage urban fabric,which constituted the boundary road in the sense of urban spacial form(morphological boundary).Compared with other social science researches which discuss region and boundary at the same time,current urban studies pay more attention to the region itself,but relatively ignore the boundary problem,which is the key to determine the definition and division of region.Therefore,taking the former British,French and Japanese concession areas in Tianjin as examples,this study focuses on the boundary roads formed in the process of urban development,aiming to clarify the construction boundary and morphological boundary as well as their formation mechanism,interpret the characteristics,properties and correlation of the boundary,and further analyze the boundary characteristics of the streetscape from the perspective of three-dimensional space.This paper studies the boundary road from three perspectives: road network characteristics,urban tissue and streetscape.In chapter two,the construction boundary and the topology boundary of road network(one of the morphology boundary)are defined and the formation mechanism is discussed by analyzing the characteristics of road network in many aspects.The third chapter further analyzes the morphological characteristics of urban tissue at the multi-scale levels of blocks,plots and buildings,and delimits the morphological boundaries of urban tissue(the other of the morphological boundary)according to different morphological elements and discusses its formation mechanism.On this basis,the fourth chapter chooses the representative road with boundary characteristics to carry on the quantitative analysis of the street spatial form,and discusses the boundary characteristics of the streetscape in pedestrian cognition.Based on the boundary theory of political geography and ecology,the study further finds that the construction boundary,as a physical boundary or a social boundary,is permeable to different degrees,which affects the evolution process of physical space and social space in the former concession area(Chapter 2).The morphological boundary of urban tissue varies with different morphological elements and has clear scale and hierarchy.The complex boundary characteristics from different research perspectives reflect the diversified relationship between the morphological boundary and the construction boundary(Chapter 3).Due to its permeability and scale hierarchy,most boundary roads present superimposed spatial structures,resulting in the landscape differences of the boundary not reflected on the two sides of a single road,but dissolved in the inside of the block.Only a few of the streetscapes on both sides of the boundary roads have clear boundary characteristics(Chapter 4).To sum up,the boundary problem within the city is not only reflected in the road network planning and construction,but also reflected in the physical spatial form of the city,and related to the streetscape from the perspective of three-dimensional space.Firstly,by clarifying the construction boundary and morphological boundary as well as their formation mechanism,this study interprets their characteristics,properties and interrelation,which enriches the cognition of boundary issues in urban research and provides reference for future conservation planning to define regions and boundaries in a more detailed and accurate manner.Secondly,through the analysis of the spatial morphological characteristics of the boundary road,the value of the street as an element of urban space is further analyzed,which provides a reliable basis for future street design guidelines and other control and improvement methods.