Detection of water infiltration and deformation of unsaturated soils by elastic wave velocity
Detection of water infiltration and deformation of unsaturated soils by elastic wave velocity
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DOI：
10.1007/s10346-017-0825-8
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发表时间：
2017-10-01
期刊：
影响因子：
6.7
通讯作者：
Xie, Jiren
中科院分区：
文献类型：
--
作者：
Chen, Yulong;Uchimura, Taro;Xie, Jiren
强降雨是最重要的滑坡诱因。在世界上许多山区环境中，强降雨在几秒钟内就造成了许多山体滑坡和边坡破坏，而没有任何警告。因此，早期预警系统可以有效地减少山泥倾泻和斜坡坍塌造成的损害，帮助人们及时撤离易发生山泥倾泻的地区。在本研究中，我们提出了一个想法，通过弹性波在土壤中的传播来关联土壤水分变化和坡面变形。通过恒剪应力排水三轴试验和人工降雨条件下的边坡模型试验，研究了边坡破坏前雨水入渗变形阶段的弹性波速响应。分析结果表明，弹性波速随含水率和变形的变化而不断减小，且在破坏开始时波速的减小速率有明显的波动。根据试验结果解释了可能的机制。建议在波速下降率开关处发出警告。因此，这种方法可以作为一个早期预警系统的滑坡和边坡破坏的含水量和变形的基础。
Intense rainfall is the most important landslide trigger. In many mountainous environments of the world, heavy rainfall has caused many landslides and slope failures in a matter of seconds without warning. Therefore, an early warning system can be an effective measure to reduce the damage caused by landslides and slope failures by facilitating the timely evacuation of people from landslide-prone areas. In this study, we propose an idea to correlate soil moisture changes and deformations in slope surface by means of elastic wave propagation in soil. Constant shear stress drained triaxial tests where water was infiltrated from the bottom of specimen until failure, and slope model tests under artificial rainfall were performed to investigate the response of elastic wave velocities during pre-failure phases of rainwater infiltration and deformation. Analysis of the results has established that the elastic wave velocity continuously decreases in response of moisture content and deformation, and there was a distinct surge in the decrease rate of wave velocity when failure was initiated. Possible mechanisms were interpreted based on the test results. It is proposed that a warning be issued at switch of wave velocity decrease rate. This approach can thus serve as the basis of an early warning system for landslides and slope failure considering both moisture content and deformation.