Papers reported in the 7th International Symposium on \u22Novel Carbon Resource Sciences\u22 Jun. 23-24, 2011A high terrain area with steep slope is one of the geotechnical problems in the geothermal field, which caused instability of the main facilities. A long period of heavy rain and the topography such as a steep slope could cause the land slides in the surrounding area of the main geothermal facilities, such as geothermal pipeline.Once landslides occur, either a part or all of the geothermal facilities may be moved away from their original positions. The data of soil profile obtained only from the borehole data shows a limitation to identify the shape of landslide and the surface of failure. It may be difficult to evaluate the slope stability accurately only by using this data. Hence, integrated soil investigation which consists of borehole, Standard Penetration Test, Cone Penetration Test, Geophysical Survey, and Engineering Geology Mapping and Ground Water is proposed in this paper and this method can not only improve the geotechnical data but also discuss the mechanism of landslide more accurately
