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、2008年中国汶川地震等山区重大地震后进行的损害调查表明，造成问题的不仅仅是强烈震动和相关现象。也包括受地震影响的山体边坡的震后失稳，后者是指抢险救援和重建期间边坡失稳、底部道路运输等。不稳定的斜坡容易受到斜坡破坏的影响，特别是在降雨期间，为了保护此类重要的紧急活动免受斜坡问题的影响，人们认为有必要采取一些结构措施，但规划的结构不必如此。由于所保护的道路交通不是普通类型，而是紧急车辆，在特殊情况下安全性要求不是很高，因此本研究旨在研究一种简单且安全的坡地结构。可减轻影响的便携式隧道结构中心目标是评估泥石流与防护结构之间的冲击力，因为不可能对遭受泥石流的真实规模结构进行研究，因此进行了小规模模型研究。根据碎片数量、碎片类型、斜坡长度、坡度和斜坡表面的摩擦力，对受影响结构中的冲击压力分布、时间历程和弯矩进行重复测试，从而得出回归结果。进行分析以获得这些值的经验公式。此外，还引入了能量观点，以更合理的方式研究显着冲击力的产生机制。此外，还开发了离散元分析，以在更大范围内数值再现冲击现象。这些努力是为了将小规模模型测试的结果应用于现场更大的原型。