Abstract
The Fugoppe Cave is located at Maruyama Hill, Yoichi Beach, Hokkaido, Japan, and is designated as a National Cultural Heritage. The Cave has very unique engraved rock arts on rock walls, which are known to have been sculptured ca. 1, 600 y. B. P. The rock arts of walls were discovered in 1950 by high school student. The engraved walls of Fugoppe Cave have been weathered and occurred separation on the walls. As a result, the rock arts such as human bodies and boats, have become obscure. Furthermore attention has been called to be afraid of rock fall from the walls, because many cracks have been appearing on the wall. These factors have led to perform engineering geological investigations. The contents of the investigations were to obtain fundamental data, such as detailed topographic photo images of quadrangle grids. Based on the photographic images, we evaluated the possibility of rock fall and wall separation from engineering geological point of view. These engineering geological investigations can be useful and may become a standard sample for conservation of prehistoric site, such as rock arts, and stone images of Buddha, not only in Japan but also in the world.
