Ngoc Ha Do, Satoshi Goto, Hirotaka Ochiai, Shiho Asano, Huy Loi Doan, Thanh Binh Huynh, Junji Yoshida
{"title":"Mechanism of a rainfall-induced landslide in a large-scale flume experiment on a weathered granite sand","authors":"Ngoc Ha Do, Satoshi Goto, Hirotaka Ochiai, Shiho Asano, Huy Loi Doan, Thanh Binh Huynh, Junji Yoshida","doi":"10.1186/s40677-024-00280-x","DOIUrl":null,"url":null,"abstract":"A large-scale flume experiment was performed to evaluate the mechanism of landslide occurrence due to rainfall using weathered granite sand. The dimensions of the flume were 9 m (length), 1 m (width), and 1 m (depth). The weathered granite sand from the actual landslide site at Da Nang City, Vietnam was used. The pore water pressure was measured by a pore-water pressure transducer at two depths (middle and bottom) to determine the process of rainwater infiltration into the soil. The surface deformation was measured with extensometers at three positions of the slope. The deformation of the entire slope was determined by the 160 cylindrical-shaped makers evenly spaced in the slope and three cameras. The results showed that the rainfall infiltrated into the slope process, increasing from negative pore water pressure to approximately 0. The maximum shear strain contour has been plotted in total and in time increments. The shear band was detected from the time increments maximum shear strain contour. The localization in the shear band formed just before failure. To the best of our knowledge, this is the largest scale laboratory test ever conducted to calculate the shear band. Moreover, it was found that the failure occurred when the sand was in an unsaturated phase. Failure does not seem to depend on the increase in pore water pressure but on the maximum shear strain. This feature can be used to explain the phenomenon of landslides that occur even when the groundwater level does not increase but large deformation occurs.","PeriodicalId":37025,"journal":{"name":"Geoenvironmental Disasters","volume":null,"pages":null},"PeriodicalIF":3.8000,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geoenvironmental Disasters","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1186/s40677-024-00280-x","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
A large-scale flume experiment was performed to evaluate the mechanism of landslide occurrence due to rainfall using weathered granite sand. The dimensions of the flume were 9 m (length), 1 m (width), and 1 m (depth). The weathered granite sand from the actual landslide site at Da Nang City, Vietnam was used. The pore water pressure was measured by a pore-water pressure transducer at two depths (middle and bottom) to determine the process of rainwater infiltration into the soil. The surface deformation was measured with extensometers at three positions of the slope. The deformation of the entire slope was determined by the 160 cylindrical-shaped makers evenly spaced in the slope and three cameras. The results showed that the rainfall infiltrated into the slope process, increasing from negative pore water pressure to approximately 0. The maximum shear strain contour has been plotted in total and in time increments. The shear band was detected from the time increments maximum shear strain contour. The localization in the shear band formed just before failure. To the best of our knowledge, this is the largest scale laboratory test ever conducted to calculate the shear band. Moreover, it was found that the failure occurred when the sand was in an unsaturated phase. Failure does not seem to depend on the increase in pore water pressure but on the maximum shear strain. This feature can be used to explain the phenomenon of landslides that occur even when the groundwater level does not increase but large deformation occurs.
期刊介绍:
Geoenvironmental Disasters is an international journal with a focus on multi-disciplinary applied and fundamental research and the effects and impacts on infrastructure, society and the environment of geoenvironmental disasters triggered by various types of geo-hazards (e.g. earthquakes, volcanic activity, landslides, tsunamis, intensive erosion and hydro-meteorological events).
The integrated study of Geoenvironmental Disasters is an emerging and composite field of research interfacing with areas traditionally within civil engineering, earth sciences, atmospheric sciences and the life sciences. It centers on the interactions within and between the Earth''s ground, air and water environments, all of which are affected by climate, geological, morphological and anthropological processes; and biological and ecological cycles. Disasters are dynamic forces which can change the Earth pervasively, rapidly, or abruptly, and which can generate lasting effects on the natural and built environments.
The journal publishes research papers, case studies and quick reports of recent geoenvironmental disasters, review papers and technical reports of various geoenvironmental disaster-related case studies. The focus on case studies and quick reports of recent geoenvironmental disasters helps to advance the practical understanding of geoenvironmental disasters and to inform future research priorities; they are a major component of the journal. The journal aims for the rapid publication of research papers at a high scientific level. The journal welcomes proposals for special issues reflecting the trends in geoenvironmental disaster reduction and monothematic issues. Researchers and practitioners are encouraged to submit original, unpublished contributions.