Basal interstitial water pressure in laboratory debris flows over a rigid bed in an open channel
Measuring the interstitial water pressure of debris flows under various conditions gives essential information on the flow stress structure. This study measured the basal interstitial water pressure during debris flow routing experiments in a laboratory flume. Because a sensitive pressure gauge is r...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2012-08-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | http://www.nat-hazards-earth-syst-sci.net/12/2499/2012/nhess-12-2499-2012.pdf |
| _version_ | 1811259209253126144 |
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| author | N. Hotta |
| author_facet | N. Hotta |
| author_sort | N. Hotta |
| collection | DOAJ |
| description | Measuring the interstitial water pressure of debris flows under various conditions gives essential information on the flow stress structure. This study measured the basal interstitial water pressure during debris flow routing experiments in a laboratory flume. Because a sensitive pressure gauge is required to measure the interstitial water pressure in shallow laboratory debris flows, a differential gas pressure gauge with an attached diaphragm was used. Although this system required calibration before and after each experiment, it showed a linear behavior and a sufficiently high temporal resolution for measuring the interstitial water pressure of debris flows. The values of the interstitial water pressure were low. However, an excess of pressure beyond the hydrostatic pressure was observed with increasing sediment particle size. The measured excess pressure corresponded to the theoretical excess interstitial water pressure, derived as a Reynolds stress in the interstitial water of boulder debris flows. Turbulence was thought to induce a strong shear in the interstitial space of sediment particles. The interstitial water pressure in boulder debris flows should be affected by the fine sediment concentration and the phase transition from laminar to turbulent debris flow; this should be the subject of future studies. |
| first_indexed | 2024-04-12T18:27:05Z |
| format | Article |
| id | doaj.art-26929af77de1473884461ad4948987bb |
| institution | Directory Open Access Journal |
| issn | 1561-8633 1684-9981 |
| language | English |
| last_indexed | 2024-04-12T18:27:05Z |
| publishDate | 2012-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Natural Hazards and Earth System Sciences |
| spelling | doaj.art-26929af77de1473884461ad4948987bb2022-12-22T03:21:11ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812012-08-011282499250510.5194/nhess-12-2499-2012Basal interstitial water pressure in laboratory debris flows over a rigid bed in an open channelN. HottaMeasuring the interstitial water pressure of debris flows under various conditions gives essential information on the flow stress structure. This study measured the basal interstitial water pressure during debris flow routing experiments in a laboratory flume. Because a sensitive pressure gauge is required to measure the interstitial water pressure in shallow laboratory debris flows, a differential gas pressure gauge with an attached diaphragm was used. Although this system required calibration before and after each experiment, it showed a linear behavior and a sufficiently high temporal resolution for measuring the interstitial water pressure of debris flows. The values of the interstitial water pressure were low. However, an excess of pressure beyond the hydrostatic pressure was observed with increasing sediment particle size. The measured excess pressure corresponded to the theoretical excess interstitial water pressure, derived as a Reynolds stress in the interstitial water of boulder debris flows. Turbulence was thought to induce a strong shear in the interstitial space of sediment particles. The interstitial water pressure in boulder debris flows should be affected by the fine sediment concentration and the phase transition from laminar to turbulent debris flow; this should be the subject of future studies.http://www.nat-hazards-earth-syst-sci.net/12/2499/2012/nhess-12-2499-2012.pdf |
| spellingShingle | N. Hotta Basal interstitial water pressure in laboratory debris flows over a rigid bed in an open channel Natural Hazards and Earth System Sciences |
| title | Basal interstitial water pressure in laboratory debris flows over a rigid bed in an open channel |
| title_full | Basal interstitial water pressure in laboratory debris flows over a rigid bed in an open channel |
| title_fullStr | Basal interstitial water pressure in laboratory debris flows over a rigid bed in an open channel |
| title_full_unstemmed | Basal interstitial water pressure in laboratory debris flows over a rigid bed in an open channel |
| title_short | Basal interstitial water pressure in laboratory debris flows over a rigid bed in an open channel |
| title_sort | basal interstitial water pressure in laboratory debris flows over a rigid bed in an open channel |
| url | http://www.nat-hazards-earth-syst-sci.net/12/2499/2012/nhess-12-2499-2012.pdf |
| work_keys_str_mv | AT nhotta basalinterstitialwaterpressureinlaboratorydebrisflowsoverarigidbedinanopenchannel |