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泥石流对坡面土壤侵蚀强度研究是泥石流动力过程研究的重要组成部分,而沿程障碍物的存在对其侵蚀强度具有重要影响。基于宾汉模型理论推导建立了有、无障碍物下泥石流侵蚀坡面土壤本构模型,以南京老山某区域为研究对象,建立室内边坡模型,人工模拟泥石流侵蚀坡面土壤过程,进行速度、坡面土壤侵蚀形态及堆积范围相关分析。研究发现:无障碍物下,泥石流一直处于加速运动状态,坡面松散颗粒受剪切力作用而发生移动,从而产生坡面侵蚀,在水平距离60 cm处侵蚀土壤最深达到25 cm,堆积体为叠式堆积扇;障碍物的存在对泥石流具有分流和拦挡作用,分流后的运动体速度和质量均减小,低于同时刻下无障碍物情况,最终在堆积区形成两个堆体;障碍物位置越靠上,分流和质量分配发生越早,新的速度和冲击力越小,沿程携带固体物质能力越弱,坡面土壤在侵蚀坑的深度变化越不明显,对下游坡面土壤的保护效果越好;对比障碍物沿轴向逆时针旋转0°和15°,两种情况下的质量分配比和堆积面积比近似相等,分别为1∶1和1∶2,虽然在15°下右侧分配质量较多,但动能不及左侧,故侵蚀能力较弱,对下游区域的保护效果较明显。
Debris flow on the slope soil erosion intensity is an important part of the process of debris flow dynamics, while the presence of obstacles along the path of its erosion intensity has an important impact. Based on Bingham model theory, the soil constitutive model of debris flow erosion slope with and without obstructions was deduced. Taking a section of Laoshan in Nanjing as an example, an indoor slope model was established to simulate the process of debris flow erosion on the slope soil. Correlation Analysis of Slope Soil Erosion Morphology and Accumulation Range. The results show that under the condition of no obstacle, the debris flow always accelerates, and the loose particles on the slope move by the shear force, resulting in slope erosion. The depth of soil erosion reaches to 25 cm at the horizontal distance of 60 cm, Stacked stacking fans. The presence of obstacles has the effect of diversion and blockage on the debris flow. The velocity and mass of the moving body after shunt reduction are lower than those without obstacles at the same time, and eventually form two piles in the accumulation area. The higher the position is, the earlier the shunt and mass distribution occurs. The lower the new velocity and impact force, the weaker the ability to carry solid material along the path. The less obvious the change of soil depth in the erosion pits is, The better the protective effect, the comparative obstacles rotate 0 ° and 15 ° counterclockwise in the axial direction. The mass distribution ratio and stacking area ratio are approximately equal in both cases, respectively, at 1: 1 and 1: 2, although at 15 ° The right side of the distribution of more quality, but the kinetic energy is less than the left, so the erosion of weak, more effective protection of the downstream area.