Abstract
This paper shows a construction example of a large excavation slope in Kobe, Japan. According to previous landslide cases and geological investigations near the construction site, we thought that there were three layer-parallel fracture zones which formed landslide surfaces. And there was no geotechnical information about the lowest landslide surface. So we carried out additional geological investigations, and the result implied that there was an unstable, dip slope structured block separated by several faults. Based on these geotechnical and geological knowledge, we specified the most important issues in designing the slope were as follows; When the excavation work executed, how large the displacement range would be by the release of in-situ stress, How strong the sliding surface would be. To solve these issues, we constructed a test excavation slope and carried out field observations. Based on the field observation results, we could estimate the displacement range and the strength of the sliding surface, so we designed and constructed the countermeasures against landslide. We carried out field observation during the construction too, and we confirmed the stability of the large excavation slope up to the completion.
