A study on characteristics of composition method of inner foundation in stone stupa

석탑 기단부 적심구성방법에 대한 특성 고찰 - $7{\sim}8$세기 석탑 중 해체 수리한 석탑을 중심으로 -

Through analysing on construction cases of stupa built in A.D. 7,8th, I have researched about these : constructive methods of inner soil of stupa, spatial compositions, characteristics of structures, arrangements of inner soil and etc. And cases analysed are six ; Mireuksajiseoktap(stone pagoda of Mireuksa Temple site), Gameunsajisamcheumgseoktap(three storied stone pagoda of Gameunsa Temple site), Goseonsajisamcheungseoktap(three storied stone pagoda of Goseonsa Temple site), Wolseong nawolliocheungseoktap(five storied stone pagoda in Nawonri, Wolseong), Guksagokseoktap(three storied stone pagoda in Guksa valley), Giamgokseoktap(three storied stone pagoda in Giam valley). Additionally we researched about inner soil of Sacheonwangsaji tapji(basement of stone stupa site in Sacheonwang Temple site) to speculate on composition of Synthetically, the foundation could be divided as core space and outer space. ; the former as structural function and the latter as ornamental function. And the core area could be divided again as center column space and buffer space. The relationship between core spaces and its formation are as belows; First, according to the area of foundation and scale of stone pagoda, formations of core are differed. As the scale of stone pagoda goes bigger, and the area of foundation goes larger, the structure of stone pagoda comprised by center column type and layered-core which endure upper load independently. On the contrary, as the scale of stone pagoda goes smaller, and the area of foundation goes lesser, the structure of stone pagoda tend to use only center column to endure upper part. Second, spatial composition of core area is comprised as two spaces, one which endure upper load and buffer space which absorb side pressure and upper pressure. The buffer space tend to be used in case of those structures which could not endure side pressure or have lots of joint. In some cases, it was located below the cover stone of foundation and gained upper load. And in case that have not gained pressure from side stone, the buffer space are comprised by smalle stone or roof tile to get structural supplement.