The effects of climate change including intense rainfalls have resulted in many slope failures. The bioengineering method using vegetation is an environmentally friendly alternative for slope stabilisation. This paper presents the effect of root reinforcement on the stability of vegetated slope under rainfall condition. A transient seepage and slope stability analysis was conducted based on the finite-element and limit equilibrium methods. Field monitoring on a residual soil slope in Thailand was numerically modelled. In transient seepage analysis, the soil-water characteristic curve and the saturated permeability measured from laboratory and in situ tests were used, and the results were comparable with the monitored values from the site. For slope stability analysis, the effective shear strength parameters from direct shear tests were used to model the well-compacted and non-compacted soil slopes. The additional shear strength of soil from the root cohesion was modelled for vegetated soil slope. The results show that the contribution of root cohesion to slope stability was more significant for the non-compacted soil condition than for the well-compacted one. Both modelled and monitored pore-water pressure reached the highest values about 1 d after the daily rainfall had reached its peak. This finding has a significant implication for landslide warning based on rainfall.

中文翻译：

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降雨条件下泰国植被残留土坡的稳定性分析

气候变化的影响，包括强降雨，导致许多边坡倒塌。使用植被的生物工程方法是边坡稳定的环保选择。本文介绍了根部加固对降雨条件下植物坡稳定性的影响。基于有限元和极限平衡法进行了瞬态渗流和边坡稳定分析。对泰国残余土壤坡度的现场监测进行了数值模拟。在瞬态渗流分析中，使用了实验室和现场测试测得的土壤-水特征曲线和饱和渗透率，其结果与现场监测值相当。为了进行边坡稳定性分析，直接剪切试验的有效抗剪强度参数被用来模拟压实和非压实的土质边坡。根据植被的坡度，模拟了根系内聚力对土壤的附加抗剪强度。结果表明，在非压实土壤条件下，根部内聚力对边坡稳定性的贡献比在压实土壤条件下更为显着。每日降雨量达到峰值后约1 d，模拟和监测的孔隙水压力均达到最高值。这一发现对于基于降雨的滑坡预警具有重要意义。结果表明，在非压实土壤条件下，根部内聚力对边坡稳定性的贡献比在压实土壤条件下更为显着。每日降雨量达到峰值后约1 d，模拟和监测的孔隙水压力均达到最高值。这一发现对于基于降雨的滑坡预警具有重要意义。结果表明，在非压实土壤条件下，根部内聚力对边坡稳定性的贡献比在压实土壤条件下更为显着。每日降雨量达到峰值后约1 d，模拟和监测的孔隙水压力均达到最高值。这一发现对于基于降雨的滑坡预警具有重要意义。