Fluidized landslides pose significant hazards owing to the catastrophic failure and flow-like behavior with high mobility and long traveling distances. Non-plastic fines can be abundant in many fluidized landslides with 30%–40% content of relatively fine-grained particles. However, the role of fine particles in the initiation and movement of these landslides is not well understood. To investigate the effects of non-plastic fines content (FC) on the undrained shear behavior of the mixture, undrained ring shear tests were performed on mixtures of silica sand ( = 0.16 mm) with varying weight proportions of non-plastic fines ( = 0.035 mm) with different initial densities. We showed that liquefaction potential increased as fines content increased and initial density decreased. Peak strength (), steady-state strength (), and total dissipated shear energy to the steady state () increased against increasing density of the sample. Given the same initial density, , and decreased with the increases of FC. Using intergranular void ratio () and equivalent intergranular void ratio (), we found that plots of , and against merged to a relatively narrow domain, indicating can serve as a comprehensive indicator for evaluating the FC's effects on undrained shear behavior. An optimum existed for the mixtures, which corresponds to the minimal brittleness index , that is used for analyzing liquefaction associated with post-failure behavior. The in the log scale continuously decreased with increasing . We inferred that the addition of fine particles could change the inter-particle force transfer. When the FC increases, a greater proportion of fines can actively engage in the forces transferring structure as active fine particles, resulting in increasing liquefaction potential and reducing the energy dissipation throughout the entire shearing process of the saturated mixtures, thereby facilitating the fluidization and mobility of landslides. This study provides an evaluation of the full liquefaction process of fines-rich mixtures and further explains the fines' role in the high mobility of fluidized landslides based on the energy dissipation view.

中文翻译：

---

非塑性细砂混合物在大剪切位移下的不排水剪切行为研究

由于灾难性的破坏和流动性高、移动距离长，流化滑坡造成了重大危险。许多流化滑坡中含有丰富的非塑性细粒，其中相对细粒颗粒的含量为 30%–40%。然而，细颗粒在这些滑坡的引发和运动中的作用尚不清楚。为了研究非塑性细粒含量 (FC) 对混合物不排水剪切行为的影响，对不同重量比例的非塑性细粒 (= 0.035) 的硅砂 (= 0.16 mm) 混合物进行了不排水环剪试验。 mm) 具有不同的初始密度。我们发现液化潜力随着细粉含量的增加和初始密度的降低而增加。峰值强度 ()、稳态强度 () 和稳态总耗散剪切能 () 随着样品密度的增加而增加。给定相同的初始密度， 和 随着 FC 的增加而减小。利用粒间空隙率（）和等效粒间空隙率（），我们发现 、 和 的图合并到一个相对较窄的区域，表明可以作为评估 FC 对不排水剪切行为影响的综合指标。混合物存在一个最佳值，它对应于最小脆性指数，用于分析与失效后行为相关的液化。对数尺度中的 随 的增加而不断减小。我们推断，细颗粒的添加可以改变颗粒间的力传递。当FC增加时，更大比例的细粉可以作为活性细颗粒积极参与力传递结构，导致液化潜力增加并减少饱和混合物整个剪切过程中的能量耗散，从而促进流体的流化和流动性山体滑坡。本研究对富含细粉的混合物的完全液化过程进行了评估，并根据能量耗散的观点进一步解释了细粉在流化滑坡高流动性中的作用。