The Interpretation for Landslide Mechanism and The Proposal of Landslide Countermeasures in Abay Gorge in Ethiopia
The Interpretation for Landslide Mechanism and The Proposal of Landslide Countermeasures in Abay Gorge in Ethiopia
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DOI:
10.1007/978-3-642-32238-9_42
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发表时间:
2013
期刊:
影响因子:
--
通讯作者:
Masao Yamada;Kensuke Ichikawa;Takeshi Kuwano;Tomonari Takeuchi;Atsushi Nakagawa
中科院分区:
文献类型:
--
作者:
Masao Yamada;Kensuke Ichikawa;Takeshi Kuwano;Tomonari Takeuchi;Atsushi Nakagawa
Main road 3, a major arterial road in Ethiopia, that passes through the Abay Gorge steeply climbs nearly 1,500 m over 40 km. It is plagued by landslides in the rainy season from June to September. Especially, the road receives big damages in L/S00, L/S05, L/S22, L/S27, and L/S28 points. The various investigation and movement observation of drilling survey, electric soundings, seismic exploration, borehole extensometer, borehole inclinometer, groundwater level meter and so on were executed in these districts. Though a lot of landslides are colluvial deposit slides, weak tuff layers are related to landslide movement. For the relationship between rainfall, groundwater level and landslide deformation, a continuous rainfall for at least four days is necessary to cause the groundwater level rising and landslide deformation. Also the time lag for water level rising after the practical effective rainfall is one day, and the time lag between water level rising and landslide deformation is two days. This paper introduces results of a full-scale investigation analysis project that executes various investigational observations and the integrated analyses lead by JICA concerning overseas landslides. Because the hydro-geological structure of landslides in Abay Gorge has been clarified from these results of investigation and landslide movement observations, the interpretation for landslide mechanism and the proposal of landslide countermeasures in Abay Gorge is shown in this paper.