结合山水地形的元大都城墙设计及尺度、模数研究

A Study on the Design and Its Scale and Module of Dadu’s City Wall in Yuan Dynasty by an Analysis of Beijing’s Terrain and Landscape

在文献研究与北京及周边山水地形分析的基础上,本文探讨了元大都城墙、城门定位与地形之间的特定关系。城墙定位体现了古人对地形高差的仔细把握和利用。元大都南北护城河间距离A=7750米、东西护城河间的距离B=6820米,与四周的标志性山水要素间距离存在模数关系;而元大都纵横两个方向的实际尺寸,又略比此尺度小一些,故反映出了地形与城池之间的良好图底关系。因而推测在元明北京城设计中,很可能存在着地形测量尺寸与设计尺寸相互参照的问题。而与模数A接近的7~8千米尺度,还普遍存在于北京周边地形山水及皇家陵寝轴线设计中。

Based on documentary research and analysis of the terrain and landscape in Beijing,this paper explores the specific relationship between the location of the Yuan Dadu city wall and its gates and the terrain,and the scale and module phenomenon in design.The location of the city wall reflected the ancient planners’comprehensive utilization of the terrain elevation.The distance of the moat from tips on south and north is A=7750 m,and the distance between east and west is B=6820 m,both relevant to the distances among the significant mountains and rivers’elements.Either A or B represented some kind of module of the terrain.However,the real corresponding dimensions of Yuan Dadu in length and breadth were little shorter than A and B,so there was a definite figure-ground relation about scale design between the city and the site.In addition,the scales from 7 km to 8 km,around Module A,widely existed in surrounding landscapes and royal architectural complex on a high level,such as Imperial Tombs from Jin to Qing dynasties in Beijing.