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Simplified protective structure against debris flow for safe transportation in mountainous region

简化山区泥石流防护结构保障山区交通安全

基本信息

批准号：
22656105
负责人：
TOWHATA Ikuo
金额：
$ 2.29万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Challenging Exploratory Research
财政年份：
2010
资助国家：
日本
起止时间：
2010 至 2011
项目状态：
已结题

项目摘要

Damage investigations that were conducted after such significant earthquakes in mountainous regions as the Niigata-Chuetsu earthquake in 2004, the Kashmir earthquake in Pakistan, 2005, and the 2008 Wenchuan earthquake in China demonstrated that problems were caused not only by the strong shaking and related phenomenon but also the post-earthquake instability of mountain slopes that were affected by the shaking. The latter means that slope failures during the period of emergency rescue and re-construction, road transportation at the bottom of unstable slopes is vulnerable to slope failures and is often stopped in particular during rain falls. To protect such important emergency activities from the slope problems, some structural measure was considered necessary. It was thought important further that the planned structure does not have to be so safe as normal structures in sloping ground because the road transportation to be protected is not of the ordinary type but are the emergency veh … More icles whose safety demand is not very high under special situations. Hence, the present research intended to investigate a simple and portable tunnel structure that mitigates the effects of debris flow on road transportation. The central aim was the evaluation of the impact force between debris flow and a protective structure. Because a study on a real-scale structure undergoing debris flow is impossible, a small-scale model study was made. By changing the amount of debris, debris types, the length of a slope, its gradient, and friction of the slope surface, tests were repeated on the distribution of impact pressure, its time history, and bending moment in an affected structure. Accordingly, a regression analysis was made to obtain an empirical formula for those values. The concerned structures were a vertical retaining wall and a tunnel. In addition, an energy viewpoint was introduced to investigate in a more rational manner the mechanism of generation of significant impact force. Furthermore, a discrete element analysis was developed to numerically reproduce the impact phenomenon in a greater scale. These efforts were made to apply results from small-scale model tests to a greater proto type in the field. Less

2004年新泻-中越地震、2005年巴基斯坦克什米尔地震和2008年中国汶川地震等重大山区地震发生后的灾害调查表明，造成问题的不仅是强震及其相关现象，还有受强震影响的山坡震后失稳。后者是指在紧急救援和重建期间发生的边坡破坏，不稳定边坡底部的道路运输容易发生边坡破坏，特别是在降雨期间经常停止。为了保护这些重要的紧急活动不受斜坡问题的影响，一些结构措施被认为是必要的。此外，重要的是，规划结构不必像普通斜坡地面结构那样安全，因为要保护的道路运输不是普通类型的，而是紧急运输。更多的是在特殊情况下对安全要求不是很高的冰。因此，本研究旨在探索一种简单、便携的隧道结构，以减轻泥石流对道路运输的影响。其中心目的是评价泥石流与防护结构之间的冲击力。由于不可能对发生泥石流的真实结构进行研究，因此进行了小尺度模型研究。通过改变堆积物的数量、堆积物类型、边坡长度、坡度和边坡表面摩擦力等因素，对受影响结构的冲击压力分布、冲击压力时程和弯矩进行了反复试验。因此，进行了回归分析，以获得这些值的经验公式。有关的结构是一个垂直挡土墙和一个隧道。此外，还引入了能量的观点，更合理地探讨了显著冲击力的产生机理。此外，采用离散元分析方法在更大尺度上数值再现了冲击现象。这些努力是为了将小规模模型试验的结果应用于实地的较大原型。少