Displacement and pore-pressure data from a field-scale landslide initiation experiment at Mount Kaba-san, Japan, November 14, 2003

This data release contains displacement and pore-water pressure data from a field experiment performed November 14, 2003, at Mount Kaba-san, Japan. This experiment generated a shallow landslide, induced by water infiltration from overhead sprinkling, that mobilized into a debris flow. More information about this experiment can be found in Ochiai and others (2004). Extensometer data recorded the ground-surface locations (displacement) and pressure transducers recorded dynamic pore-water pressures within the hillslope leading up to and through rapid failure. Data were recorded at a 100-Hz sampling frequency on a National Instruments data-acquisition system. The accompanying cross-sectional diagram (Japan_exp_cross-section.png) illustrates the general instrument configuration at the start of the experiment.

Extensometers (linear position transducers) were attached to the overhead sprinkling structure and their wire cables (that extend with displacement) were attached to ground anchors downslope of the instruments. These instruments with retractable wire rope cables were manufactured by UniMeasure. Extensometer 4 had a longer wire length to better record the transition from slow sliding motion to rapid debris flow.

Extensometer Model Approx. wire length range (m)
3 JX-PA-80-N11-11S-111 2
4 HX-PA-400 8
5 JX-PA-80-N11-11S-111 2

Piezometers were directly buried pressure transducers encased in custom-built cylindrical housings (43 mm in diameter, 93 mm long) with sintered filters at their bases (refer to Japan_exp_piezometer_images.jpg). The transducers within the enclosures were manufactured by Druk, model PDCR800, with a range of 70 kiloPascals (kPa) gauge pressure. Each enclosure had two sealable tubes that extended to the ground surface after burial. These tubes allowed water to be injected into the enclosure through one tube and air to escape out the other tube. This configuration enabled full water saturation of the enclosed transducer sensors, rapid pressure transmission to the sensor diaphragms, and better recording of dynamic responses during rapid failure.

This data release contains the following files:
(1) Metadata for this data release.
(2) Data (in csv format) from the entire experiment (until about six minutes after rapid failure) downsampled to 1-Hz for ease of viewing and plotting. Time in seconds denotes time after overhead sprinkling commenced.
(3) Data (in csv format) from the rapid-failure period (24620-24640 seconds) at 100-Hz to portray dynamic responses during rapid failure.
(4) Image of experiment cross section showing instrument locations and landslide failure mass.
(5) Images of piezometers consisting of pressure transducers and enclosures.

Extensometer data are presented as raw recorded position (m) and corrected position (m) to reflect downslope, rather than oblique, displacement. Refer to Processing Steps in the metadata for more information on extensometer data corrections. Pore-pressure data are presented in recorded centimeters of head and converted to kPa.

Reference cited
Ochiai, H., Okada, Y., Furuya, G., Okura, Y., Matsui, T., Sammori, T., Terajima, T. and Sassa, K., 2004, A fluidized landslide on a natural slope by artificial rainfall: Landslides, v. 1, p. 211-219.