The purpose of this paper is to reconstruct the original floor plan and wall design of Seokbulsa Grotto in Kyungju; commonly known as ‘Seokguram’. The paper presents an array of dimensional studies of the existing Seokguram to examine its architectural form, and infers the original floor plan and wall design of Seokbulsa Grotto. Seokbulsa Grotto is designed as a system of 'coherent modules' and was constructed using the dry stone method, which interlocks large stone modules into a whole that becomes the load-bearing structure itself. The design principles governing Seokbulsa Grotto are the spatial axis of symmetry, modular coordination, and the layout grid of a quarter Tang-Ruler(TR: 唐尺). Dimensional studies were conducted with these governing principles in mind and concludes the following about the original floor plan design. In the main chamber, Ansang-stone’s radius is 12 TR, and Flagstone’s radius is 121/4 TR. In the front chamber, the width between the two Ansang-stones facing each other is 22 TR and the longitudinal space depth is 12 TR, while the width between the two Flagstones facing each other is 221/2 TR and Flagstone’s depth is 12 TR. In the passageway, the width between the two Ansang-stones facing each other is 111/2 TR and longitudinal space depth is 9 TR, while the width between the two Flagstones facing each other is 12 TR and Flagstone’s depth is 73/4 TR. The distance from the center to the entrance line of the main chamber is 101/2 TR. Therefore, the total longitudinal length of the Grotto is 431/2 TR at the level of the Ansang-stones, and 44 TR at the level of the Flagstones.

Abstract
1. 들어가는 말
2. 석불사 석굴의 수리 공사와 설계 원리
    2-1. 석불사 석굴의 공간 대칭축
    2-2. ‘대불상시준선’과 공간 대칭축
    2-3. 석굴암의 불상판석 모듈
    2-4. 기하학적 해석과 배치 그리드
3. 석불사 석굴에서 벽면 돌의 평면 배치
    3-1. 주실 안상석의 배치 분석
    3-2. 주실 불상판석의 배치 분석
    3-3. 주실 이맛돌과 감실의 배치 분석
    3-4. 통로·전실에서 안상석·불상판석의 배치 분석
4. 석불사 석굴의 평면과 벽면 설계
참고문헌

• 윤재신(이화여자대학교 건축학과) | Yoon Chae-Shin