Climate change is becoming a greater global challenge, leading to more frequent and intense extreme weather events, which in turn increase mountain hazards like shallow landslides and soil erosion. Ecological slope protection using vegetation has gained increasing attention to mitigate natural disasters in recent years. While numerous studies have demonstrated the contribution of root systems to soil reinforcement, the comprehensive impact of roots on soil mechanical response under rainfall scenarios remains elusive. This study investigates the instability and deformation behaviors of root-reinforced soil through constant shear drained (CSD) tests. The role of root characteristics, including biomass, diameter, and length, in modulating the shear strength, instability and deformation behaviors of soils is investigated. The results indicate that the shear strength and stability of root-reinforced soil, as well as the inhibition effect of root on contractive deformation after the initiation of instability, increasing with greater root biomass and length and smaller root diameter. Moreover, due to the potential weak interfaces, fine or stiff long roots appear to increase the likelihood of volumetric dilation in root-reinforced soil at the later stage of unstable deformation. However, this dilatancy can be effectively resisted by increasing root planting density to form the root network. Furthermore, our experiments suggest that herbaceous vegetation with finer and longer roots is more effective in mitigating static liquefaction of soils induced by rainfall infiltration. This study helps develop a predictive constitutive model for root-reinforced soils and supports future bioengineering slope design.

中文翻译：

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恒定剪切应力路径下根系加固土的失稳和变形行为


气候变化正在成为更大的全球挑战，导致更频繁和更强烈的极端天气事件，这反过来又增加了浅层山体滑坡和水土流失等山地灾害。近年来，利用植被的生态护坡越来越受到重视，以减轻自然灾害。虽然大量研究表明根系对土壤加固的贡献，但在降雨情景下根系对土壤机械响应的综合影响仍然难以捉摸。本研究通过恒定剪切排水 （CSD） 试验研究了根系加固土的不稳定和变形行为。研究了根系特性（包括生物量、直径和长度）在调节土壤剪切强度、不稳定性和变形行为中的作用。结果表明，根系加固土的抗剪强度和稳定性，以及根系失稳开始后对收缩变形的抑制作用，随着根系生物量和长度的增加以及根直径的减小而增加。此外，由于潜在的弱界面，细根或坚硬的长根似乎增加了根系加固土在不稳定变形后期体积膨胀的可能性。然而，通过增加根系种植密度以形成根系网络，可以有效地抵抗这种扩张。此外，我们的实验表明，根系更细、更长的草本植被在减轻降雨渗透引起的土壤静态液化方面更有效。本研究有助于开发根系加固土的预测本构模型，并支持未来的生物工程边坡设计。