Abstract

Debris flows cause recurrent interruptions and permanent damages in rural road networks, representing significant economic losses. Embankments are road assets frequently exposed to debris flows, especially in mountainous areas. The potential risk of infrastructure exposed to debris flows can be assessed in terms of the probability of expected damage based on fragility curves. The aim of the study is to develop fragility curves for road embankments exposed to debris flows representative to the expected physical damage and capacity loss. Two conceptual models are proposed to describe the impact and erosion of debris flows that run perpendicularly to road embankments. Probabilistic models are then developed in terms of limit state functions and the simulation of potential scenarios. The resulting models are finally fit to log-normal distributions and compared to historical data. Headcut erosion has higher probabilities of occurrence compared to sliding failure caused by the impact of debris flow. Lower road embankments present higher probabilities of failure to the impact of debris flows, especially for dense flows. Whereas, longer interaction times of less dense flows increase the probability of headcut erosion. Two-lane roads may present 50% more probabilities of headcut erosion compared to multilane roads for similar debris flows intensity.

摘要

碎石流导致农村道路网络反复中断和永久性损坏，造成重大经济损失。路堤是经常受到泥石流影响的道路资产，尤其是在山区。基础设施遭受泥石流的潜在风险可以根据脆弱性曲线的预期损坏概率进行评估。该研究的目的是为暴露于泥石流的道路堤防制定脆弱性曲线，以代表预期的物理损坏和容量损失。提出了两个概念模型来描述垂直于路堤的泥石流的影响和侵蚀。然后根据极限状态函数和潜在场景的模拟开发概率模型。生成的模型最终适合对数正态分布并与历史数据进行比较。与泥石流冲击造成的滑动破坏相比，切头侵蚀的发生概率更高。较低的路堤在泥石流的影响下失败的可能性更高，特别是对于密集流。然而，密度较低的流的较长交互时间会增加水头侵蚀的可能性。对于类似的泥石流强度，与多车道道路相比，双车道道路可能出现 50% 以上的切头侵蚀概率。较低密度流的较长交互时间会增加切头侵蚀的可能性。对于类似的泥石流强度，与多车道道路相比，双车道道路可能出现 50% 以上的切头侵蚀概率。较低密度流的较长交互时间会增加切头侵蚀的可能性。对于类似的泥石流强度，与多车道道路相比，双车道道路可能出现 50% 以上的切头侵蚀概率。