Simulation of Slope Failure Distributions Due to Heavy Rain on an Island Composed of Highly Weathered Granodiorite Based on the Simple Seepage Analysis

Abstract

To fully and rapidly develop a real-time early warning judgment system for slope failure at the time of heavy rains including overseas, it is necessary to predict water movement in the soil at the time of rainfall. In addition, to apply the system to a place where insufficient geotechnical and geological data have been amassed, it is necessary to evaluate the risk of slope failure based on physical properties obtained from a simple soil test. Therefore, in this study, the authors set Gogoshima Island in Ehime Prefecture as a study site and evaluated the water movement over time in the soil during heavy rain using a simple prediction equation of rainfall seepage process. Soil properties were determined through simple in-situ and laboratory tests. As a result, it was found that the factor of safety for slope failure in the head and wall of a valley dissecting the hillside slope composed of granodiorite in which weathering has progressed can be planarly evaluated using the simple prediction equation.

Application of Optical Fiber Sensing Technology in Permeability Test of Three-Dimensional Physical Model of Medium and Long-Distance Diversion Tunnel

“…Most of them use multicore optical fiber clusters composed of multiple optical fibers and outer protective layers, namely optical cables. Optical cable transmission and fiber Bragg grating sensor have the following advantages compared with traditional cable transmission and electrical signal instruments: (1) it integrates transmission and sensing, with large amount of transmission data, small attenuation, and long transmission distance; (2) nonmetallic insulating materials are not affected by damp environment, high temperature resistant, corrosion resistant, and suitable for special environments such as underground engineering; (3) optical signal transmission is hardly affected by factors such as light source power, light fluctuation and connection loss, and has good stability; (4) Its small size, light weight, free from electromagnetic noise interference, high transmission quality, and sensing sensitivity; (5) The sensor has high monitoring efficiency, and a single fiber can write multiple gratings with different wavelengths for real-time quasi-distributed monitoring; (6) With good adaptability, simple structure, and small geometric size, it is suitable for embedding inside all kinds of buildings [17].…”