Evaluation of the effect of hysteretic flow and root system on shallow landslide
Kuo-Chen Ma A D , Yong-Jun Lin B , Shyh-Yuan Maa C and Yih-Chi Tan AA Department of Bioenvironmental Systems Engineering, and Center for Weather Climate and Disaster Research, National Taiwan University, Taipei 10617, Taiwan.
B Center for Weather Climate and Disaster Research, National Taiwan University, Taipei 10617, Taiwan.
C Department of Urban Planning and Disaster Management, Ming Chuan University, No. 5 De-Ming Road, Gui shan District, Taoyuan 333, Taiwan.
D Corresponding author. Email: d90622007@ntu.edu.tw
Soil Research 50(7) 616-624 https://doi.org/10.1071/SR12104
Submitted: 18 April 2012 Accepted: 1 September 2012 Published: 13 November 2012
Abstract
This paper analyses the mechanics of slope stability with regard to the hysteretic flow of unsaturated soil and the root system of the covering vegetation. The hysteresis of the soil water retention curves and root strength are important factors in the evaluation of unsaturated shear strength. Engineers should consider how the transportation of the soil water content and the plant root strength influence evaluation of surficial slope stability analysis. The integrated slope stability analysis considering the hysteretic flow and root strength were calculated on variations of the safety factor (SF) and in accordance with different infiltration profiles and several species of vegetation. The results show that it is possible to predict shallow landslide on unsaturated slopes covered by different vegetation types. Tree planting, in combination with mechanical reinforcement, on the slope’s toe was found to improve stability, in addition to having economic benefits. This process allows for the selection and comparison of combinations and densities of vegetation types, in order to find the optimum location for increased SF. This will quickly improve shallow slope stability before it is destroyed. A better understanding of the process mechanics, as provided by the model, is critical for a reliable and appropriate design for slope stabilisation.
Additional keywords: hysteretic flow, root strength, safety factor, slope stability.
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