崩塌滑坡堵江堰塞湖灾害链铁路减灾选线策略

青藏高原南缘是崩塌滑坡堵江形成堰塞湖灾害链的高风险区,而我国铁路缺乏应对堰塞湖灾害的经验。铁路灾后改建工程线路优化设计将产生直接减灾效益,而新建铁路在选线阶段就采取一些主动减灾策略,也是风险调控的重要手段。为此,以中巴经济走廊中拟建哈维连至喀什铁路Attabad堰塞湖段为研究对象,根据堰塞湖灾害特点,通过将改建工程分段设计,并对不同改建线路方案进行技术经济指标比较,完成该段改建线路设计。基于上述工作,提出以有利地形控制溢流口开挖深度、宜尽量利用既有工程、在离开湖区后集中展线尽快与既有线联接、有条件时可提高限制坡度等灾后绕湖铁路选线设计要点与高位选线、酌情预留提高限坡措施的条件、尽量不跨河等新建铁路减灾选线设计策略,希望为铁路应对崩塌滑坡堵江堰塞湖灾害链提供参考。

Railway Alignment Design in High Risk Area of Landslide and Collapse Damming with the Chain of Quake Lake Disasters

The southern margin of the Qinghai-Tibet Plateau is a high-risk area where the collapse and the landslides are likely to block the river and form a chain of dammed lake disasters. But there is less experience in China to deal with dammed lake disasters in railway construction. The line optimization design of the post-disaster reconstruction project will greatly contribute to disaster mitigation, and it is also a significant means of risk control to adopt some active disaster mitigation strategies during the new railway route design. In this paper, the Attabad Lake area of the proposed railway from Kashgar to Havelian is selected as the study area. By comparing the technical and economic indicators of different reconstruction line schemes, some major points are put forward such as the existing projects should be used as much as possible, the extending line should be connected with existing lines as soon as possible after leaving the dammed lake area. New railway route design proposes that the line should be located on a higher altitude, limiting gradient should be increased, and the construction of cross-river railway should be avoided as much as possible. The findings of this study provide some references for the railway to deal with the problems caused by the dammed lake.