Based On The Theory Of Urban Catalyst In The Old City Update Strategy Research

The old urban districts, as origins of the cities, have concentrated many historical buildings of specific periods in specific conditions through years of development, and accumulated rich regional culture and customs, constituting unique urban material and environmental fashion as well as cultural and spiritual features, which are irreplaceable and exhaustible historical and cultural resources. As urbanization in China furthers, the land resource becomes increasingly tight, and the old urban districts are becoming objects of the new round of development. In the current practice of reconstruction and restoration of many old urban districts, large-scale dismantlement for reconstruction and thorough restoration are common every where throughout the nation; the urban material environments are improved to some extent, but at the great cost of great deal of historical culture and spiritual essence. Therefore, it is obviously necessary, in China, to seek for a strategy suitable for reconstruction and restoration of the old urban districts and to realize material restoration, adaptive functional adjustment, economic recovery and revitalization of the historical blocks based on succession of the urban historical culture and spiritual essence.At the end of 1980 s,American Architects Wayne Attoe and Donn Logan brought forward a new urban design theory named as Urban Catalyst,which means that bringing in a new element strategically,it will modify the urban elements around, and enhance them in positive ways.Through comprehensive study of urban catalytic theory analysis, this paper probes into the play "urban catalyst" strategy in old town renewal application principle, the application perspective. At the same time, summarized in view of the old town renewal "urban catalyst" form of diversified types of summarizing practice patterns. Through to the Confucius temple in nanjing, chengdu wenshu fang two case analysis, from the physical form and the material form, in the shaping of the catalytic element, catalytic model on the way two aspects of the practice of catalyst type for the conservation and renewal application in practice to make the overall grasp.Inner circumferential district of Xi,an City Wall is an important historical ancient city wall of the inner ring area, after many times, but there are still many problems. This article through to Lianhu section of inner circumferential district of Xi,an City Wall of the historical evolution, field investigation and analysis of master planning guidance, discuss the existing problems and the reasons of the decline. On this basis, the analysis summarizes the potential historical resources, cultural resources, analysis of the analytical hierarchy process(ahp) to get along the lane impact factor weights in the city and urban catalyst impact factor weights. Then, update the design principle and orientation, on the theory of urban catalyst in xi ’an city alley lotus lake section the practical application of the updated design study, from the nature, function structure, road, land green space and so on catalytic strategy in detail. Finally, in view of the area of catalytic element shape and catalytic node design were studied.