{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:43:56Z","timestamp":1760240636307,"version":"build-2065373602"},"reference-count":28,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2019,8,3]],"date-time":"2019-08-03T00:00:00Z","timestamp":1564790400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["T18J15176"],"award-info":[{"award-number":["T18J15176"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Rainfall-induced landslides occur commonly in mountainous areas around the world and cause severe human and infrastructural damage. An early warning system can help people safely escape from a dangerous area and is an economical and effective method to prevent and mitigate rainfall-induced landslides. This paper proposes a method to evaluate soil moisture and shear deformation by compression wave velocities in a shallow slope surface layer. A new type of exciter and new receivers have been developed using a combination of micro electro-mechanical systems (MEMS) accelerometers and the Akaike\u2019s information criterion (AIC) algorithm, which can automatically calculate the elastic wave travel time with accuracy and reliability. Laboratory experiments using a multi-layer shear model were conducted to reproduce the slope failure. The relationships between wave velocities and soil moisture were found to be dependent on the saturation path (rain or drain); in other words, hysteresis was observed. The wave velocity ratio reduced by 0.1\u20130.2 when the volumetric water content (VWC) increased from 0.1 to 0.27 m3\/m3. When loading the shear stress corresponding to slope angles of 24, 27, 29, or 31 degrees, a drop of 0.2\u20130.3 in wave velocity ratio was observed at the middle layer, and near 0.5 at the bottom layer. After setting the shear stress to correspond to a slope angle of 33 degrees, the displacement started increasing and finally, slope failure occurred. With increasing displacement, the wave velocities also decreased rapidly. The wave velocity ratio dropped by 0.2 after a displacement of 3 mm. Monitoring long-term elastic wave velocities in a slope surface layer allows one to observe the behavior of the slope, understand its stability, and then apply an early warning system to predict slope failure.<\/jats:p>","DOI":"10.3390\/s19153406","type":"journal-article","created":{"date-parts":[[2019,8,5]],"date-time":"2019-08-05T03:25:22Z","timestamp":1564975522000},"page":"3406","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Evaluation of Soil Moisture and Shear Deformation Based on Compression Wave Velocities in a Shallow Slope Surface Layer"],"prefix":"10.3390","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2886-8517","authenticated-orcid":false,"given":"Shangning","family":"Tao","sequence":"first","affiliation":[{"name":"Department of Civil and Environmental Engineering, Saitama University, Saitama 338-8570, Japan"}]},{"given":"Taro","family":"Uchimura","sequence":"additional","affiliation":[{"name":"Faculty of Engineering, Saitama University, Saitama 338-8570, Japan"}]},{"given":"Makoto","family":"Fukuhara","sequence":"additional","affiliation":[{"name":"Department of Civil and Environmental Engineering, Saitama University, Saitama 338-8570, Japan"}]},{"given":"Junfeng","family":"Tang","sequence":"additional","affiliation":[{"name":"Department of Civil and Environmental Engineering, Saitama University, Saitama 338-8570, Japan"}]},{"given":"Yulong","family":"Chen","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Hydro science and Engineering, Tsinghua University, Beijing 100084, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0278-8842","authenticated-orcid":false,"given":"Dong","family":"Huang","sequence":"additional","affiliation":[{"name":"Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China"}]}],"member":"1968","published-online":{"date-parts":[[2019,8,3]]},"reference":[{"key":"ref_1","first-page":"373","article-title":"Some thoughts on rain-induced slope failures","volume":"3","author":"Brand","year":"1981","journal-title":"Proc. Int. Conf. Soil Mech. Found. Eng."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1007\/s10346-009-0177-0","article-title":"Early warning of rainfall-induced shallow landslides and debris flows in the USA","volume":"7","author":"Baum","year":"2010","journal-title":"Landslides"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.geomorph.2017.03.031","article-title":"Geomorphology Rainfall thresholds for possible landslide occurrence in Italy","volume":"290","author":"Peruccacci","year":"2017","journal-title":"Geomorphology"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1086","DOI":"10.1016\/j.sandf.2015.09.010","article-title":"Precaution and early warning of surface failure of slopes using tilt sensors","volume":"55","author":"Uchimura","year":"2015","journal-title":"Soils Found."},{"key":"ref_5","unstructured":"Popescu, M.E., and Sasahara, K. (2008). Engineering Measures for Landslide Disaster Mitigation. Landslides \u2013 Disaster Risk Reduction, Springer."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1081","DOI":"10.1680\/jgeot.16.P.201","article-title":"A method for the design of embedded cantilever retaining walls under static and seismic loading","volume":"67","author":"Conte","year":"2017","journal-title":"G\u00e9otechnique"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3313\/jls1964.21.1","article-title":"Landslides in Britain and their countermeasures","volume":"21","author":"Hutchinson","year":"1984","journal-title":"Landslides"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"158","DOI":"10.1016\/j.enggeo.2018.03.017","article-title":"A performance-based method for the design of drainage trenches used to stabilize slopes","volume":"239","author":"Conte","year":"2018","journal-title":"Eng. Geol."},{"key":"ref_9","unstructured":"Arnhardt, C., Asch, K., Azzam, R., Bill, R., Fernandez-Steeger, T.M., Homfeld, S.D., Kallash, A., Niemeyer, F., Ritter, H., and Toloczyki, M. (2007, January 10). Sensor Based Landslide Early Warning System\u2014SLEWS\u2014Development of a geoservice infrastructure as basis for early warning systems for landslides by integration of real-time sensors. Proceedings of the Kick-Off-Meeting, Karlsruhe, Germany."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1545","DOI":"10.1016\/S1474-7065(02)00175-4","article-title":"The use of the automatic inclinometric system for landslide early warning: The case of Cabella Ligure (North-Western Italy)","volume":"27","author":"Lollino","year":"2002","journal-title":"Phys. Chem. Earth"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"133","DOI":"10.1016\/S0013-7952(99)00122-2","article-title":"A critical review of landslide monitoring experiences","volume":"55","author":"Angeli","year":"2000","journal-title":"Eng. Geol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1007\/s10346-009-0178-z","article-title":"Simple monitoring method for precaution of landslides watching tilting and water contents on slopes surface","volume":"7","author":"Uchimura","year":"2010","journal-title":"Landslides"},{"key":"ref_13","first-page":"251","article-title":"An early warning monitoring of Earthquake-induced slope failures by monitoring inclination changes in multi-point tilt sensors","volume":"19","author":"Wang","year":"2018","journal-title":"Lowland Technol. Int."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"384","DOI":"10.1520\/GTJ10716J","article-title":"Measurement of shear waves in laboratory specimens by means of piezoelectric transducers","volume":"19","author":"Brignoli","year":"1996","journal-title":"Geotech. Test. J."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1007\/s12205-015-0404-2","article-title":"Modified triaxial apparatus for determination of elastic wave velocities during infiltration tests on unsaturated soils","volume":"20","author":"Irfan","year":"2016","journal-title":"KSCE J. Civ. Eng."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1016\/j.enggeo.2017.09.024","article-title":"Effects of soil deformation and saturation on elastic wave velocities in relation to prediction of rain-induced landslides","volume":"230","author":"Irfan","year":"2017","journal-title":"Eng. Geol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1715","DOI":"10.1007\/s10346-017-0825-8","article-title":"Detection of water infiltration and deformation of unsaturated soils by elastic wave velocity","volume":"14","author":"Chen","year":"2017","journal-title":"Landslides"},{"key":"ref_18","unstructured":"Nobutomo, O., Yoko, T., Kazuya, A., and Tomoaki, M. (2009). Realty of Cliff Failure Disaster, NILIM."},{"key":"ref_19","unstructured":"Steven, L.K. (1996). Geotechnical Earthquake Engineering, Pearson."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1785\/BSSA0670020433","article-title":"Real-time detection and location of local seismic events in central California","volume":"67","author":"Stewart","year":"1977","journal-title":"Bull. Seismol. Soc. Am."},{"key":"ref_21","first-page":"281","article-title":"Automatic Detection of Onset Time of Seismic Waves and its Confidence Interval Using the Autoregressive Model Fitting","volume":"2","author":"Morita","year":"1984","journal-title":"J-STAGE"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"538","DOI":"10.1016\/j.ultras.2004.12.005","article-title":"Strategies for reliable automatic onset time picking of acoustic emissions and of ultrasound signals in concrete","volume":"43","author":"Kurz","year":"2005","journal-title":"Ultrasonics"},{"key":"ref_23","first-page":"365","article-title":"A Method for Reading and Checking Phase Time in Auto-Processing System of Seismic Wave Data","volume":"38","author":"Maeda","year":"1985","journal-title":"Zisin J. Seismol. Soc. Japan 2nd Ser."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1007\/BF00053364","article-title":"Estimation of the arrival times of seismic waves by multivariate time series model","volume":"43","author":"Takanami","year":"1991","journal-title":"Ann. Inst. Stat. Math."},{"key":"ref_25","unstructured":"Cobos, D., and Chambers, C. (2005). Calibrating ECH2O Soil Moisture Sensors, Decagon Devices. Application Note."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1867","DOI":"10.1139\/x05-121","article-title":"Precision and accuracy of three alternative instruments for measuring soil water content in two forest soils of the Pacific Northwest","volume":"1876","author":"Czarnomski","year":"2005","journal-title":"Can. J. For. Res."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1155","DOI":"10.1007\/s10346-017-0943-3","article-title":"Elastic wave velocity monitoring as an emerging technique for rainfall-induced landslide prediction","volume":"15","author":"Chen","year":"2018","journal-title":"Landslides"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/j.enggeo.2013.12.005","article-title":"Development of shear deformation due to the increase of pore pressure in a sandy model slope during rainfall","volume":"170","author":"Sasahara","year":"2014","journal-title":"Eng. Geol."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/15\/3406\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:12:59Z","timestamp":1760188379000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/15\/3406"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,8,3]]},"references-count":28,"journal-issue":{"issue":"15","published-online":{"date-parts":[[2019,8]]}},"alternative-id":["s19153406"],"URL":"https:\/\/doi.org\/10.3390\/s19153406","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2019,8,3]]}}}