Quantitative Research On Similarity Of Architectural Facade In Historic Settings

The appearance of the building fa(?)ade in the historic district is an external manifestation of the characteristics of the historic district.It not only reflects the architectural art value of the historic district,but also reflects the changes in economy,technology and humanities during the social development.In this research,the building fa(?)ade in historic district is analyzed quantitatively through its two-dimensional morphological features with accurate data.On the basis of this,this paper further analyzes the inherent laws contained in the building fa(?)ade of historical blocks.From the perspective of visual cognition,according to the different scale levels,the two-dimensional morphological features of building facades would be expressed as outline geometry,component structure and detail visual complexity which are studied through mathematical statistics,Landscape ecology and fractal geometry.According to the principle of graphic analysis,the geometric features of the building facade can be expressed by the measurement,proportionality and shape index of the facade graphic.The directionality of building facade graphics can be preliminarily judged by the ratio calculation,and the complexity of the graphic outline is described by the shape index.The results show that if the shape index is larger,the contour of the figure is more complex.Conversely,the simpler the contour of the figure is.In the middle scale level,the structural relationship of the interior elements in graphic influences the fa(?)ade form.The analysis of the fa(?)ade structural relationship could be transformed into the analysis of the window structureal relationship through the theory of figure-ground reation.By analyzing the window pattern,the constitutive property of the facade is described quantitatively.Based on the theory of environmental psychology,this study divides the main factors that affect the structural cognition of fa(?)ade into three categories: the degree of actuality,the degree of aggregation and the degree of uniformity of the window.The degree of actuality reflects the change of the size and number of the window,which can be represented by degree of blurring,degree of fragmentation and area of the window;the degree of aggregation reflects the relative position between the windows,which is described by the degree of aggregation parameter;The degree of uniformity of the window is expressed through the horizontal and vertical interface density and uniformity.There are rich details in historic district building facades,and details belong to the small-scale level in building fa(?)ade.Reasonable detail organization and arrangement can offer the building facade necessary complexity and richness,to establish the small-scale architectural order.Based on the theory of fractal geometry,the visual complexity and richness of building facade can be quantitatively described by the fractal values of building facades.Finally,on the basis of quantitative analysis of different levels including architectural outline,graphic structure and graphic details,the similarities and differences of building fa(?)ade in historic district are compared and evaluated.The paper dicusses the main characteristics and mechanisms of building facade form through quantitative research on its facade morphology and the quantitative analysis framework is applied in four different historic districts.The research shows that the historical facade formed by the top-down urban form control and the bottom-up architectural form design is of strong integrity and high similarity and small difference.This paper claims that the morphological characteristics of the facade in historic blocks can be accurately described by quantitative analysis and the quantitative results provide the basis for the comparison,classification and commentary of different historical blocks.