Abstract
About twenty years ago a large slope failure happened at San-in Railway Line between Nago and Nagato-Ohi. There were 3 times of failure within 2 months. The author surveyed the field after the 2nd failure, and persisted that it had better to reopen the railway after removing earth and sand on the top of the slope. Although the compromise was unwilling, the author finally agreed to reopen the operation under the condition of carrying out the measurement of land distortion. However, 3rd failure happened after 2 weeks of reopening. Fortunately, the failure occurred in 40 minutes after from a train passed the area. It was the calamity with a possibility of becoming a large disaster by the case.
Why did it become such a situation? The author looks back on this disaster based on past data and memorandums, and takes a good reflection and gets some teachings for the future.
