A Study On The Architectural Form And Construction System Of Tang Dynasty Eaves In Cave 196 Of Mogao Grottoes In Dunhuang

Widely distributed,large in scale and complete in system,with deep historical and cultural connotations,Cave temples in China are unique among the country’s cultural heritage as an important type of ancient architecture.Cave eaves architecture is an important part of cave temples,and also carries a wealth of historical and cultural information from various periods.However,the majority of the cave temples in China were constructed with wooden structures,and today most of them have been destroyed,leaving a large number of cave temples exposed to the natural environment for a long time and in need of effective measures to be protected.The Mogao Grottoes are the oldest,largest,richest and best-preserved repository of Buddhist cave art in China and the world,they have been the site of numerous cave eaves buildings throughout history.The five preserved Tang and Song wooden cave eaves and the relics of cliff surface beam cave are all significant testimony to the glorious history of the Mogao Grottoes.Among them,Cave 196 is the largest,earliest and most unique example of the five Tang and Song wooden cave eaves in the Mogao Grottoes,and is the only remaining wooden cave temple eaves building in the country’s five recognised Tang dynasty buildings,occupying an important position in research.Therefore,Cave 196 is not only the indispensable empirical evidence for the study of Tang Dynasty wooden cave eaves architecture,but also an important physical source of information on the construction system and history of ancient Chinese architecture.This paper is a case study of the eaves of Cave 196 in the Mogao Grottoes during the Tang Dynasty and addresses the origin,spread,and development of eave architecture.Based on historical documents and the research results of previous scholars,the study clarifies the origins and historical evolution of cave eaves architecture,interprets the cultural connotations contained in its evolution,taking into account the current state of preservation of the cave eaves.Then,using the Tang Dynasty eaves of Cave 196 of the Mogao Grottoes as the object of study,combined with relevant historical documents,we obtained comprehensive data on the wooden eaves of Cave 196 by relying on traditional mapping methods such as on-site survey records,manual measurements and topography,as well as high-tech methods such as unmanned aerial photography and three-dimensional laser scanning.Then,on the basis of several reviews of the mapping data,the Song "Building Method" is used as the basis to analyze the architectural form and structural characteristics of the eaves of Cave 196,comparing the mural architecture and architectural examples of the same period.We find that the eaves of Cave 196 strictly followed the basic building system and modalities,and that the overall design was neat and rigorous,reflecting the widespread application of the code system at the peak of China’s ancient architecture.The main findings are as follows.(1)Cave eaves architecture is an integral and important part of cave temples and has far-reaching historical origins.From the Indian cave windows to the stone imitation of wooden cave eaves in China,and then to the wooden hall or heavy pavilion eaves in front of the cave,the eaves of the caves were built to complement the excavation of the cave temples.Cave 196 of the Mogao Grottoes was created around 892-893 AD and is one of the few caves with both front and back rooms intact,its eaves are the only well-preserved eaves from the Tang dynasty in the Mogao Grottoes and even in China.Its cave eaves architecture is magnificent,rigorous and open with distinctive architectural features of the Tang Dynasty.(2)Cave 196 of the Mogao Grottoes follows the spatial layout of a multi-entry monastery and the form of hall architecture,resulting in a spatial structure system of cave eaves,front rooms,canals,and main rooms that is in keeping with Chinese aesthetic sensibilities.The structure system is a crystallization of wisdom in the process of the Chineseization of cave temples and the grottoization of monastery architecture.(3)The architectural form and structural features of Cave 196 are similar in overall appearance and structural features,comparing with those of the surviving Tang Dynasty buildings,the Song Dynasty eaves of the Mogao Grottoes,and the Tang and Song architectural images in the wall paintings.They have significant architectural features from the Tang and Song periods,the architectural form and detailed structure partially follows the structural features of earlier buildings.(4)The eaves of Cave 196 of the Mogao Grottoes were designed and built in strict accordance with the material division system,using the construction of 300 mm / foot.The whole foot or half foot was used to control the layout of the plane space.The ideal scale for the eaves of the cave is 11 feet between centres,9.5 feet between secondary centres,30 feet in width,15.4 feet in depth and 12 feet in height of the pillars;the material used for the eaves of the cave is 12 mm at 1°,six inches(180mm)at 15° and four inches(120mm)at 10°,the dimensions of the material used are the same as the six grades specified in “Sate Building Standards”.