汶川地震对道路工程选线的影响

The Impact of Wenchuan Earthquake on Railway Route Selection

研究目的:研究如何在工程建设的源头——选线阶段通过合理的选线,从而达到科学地减震防灾的目的。研究结论:(1)在高烈度震区特别是断裂带附近选线时,当以路基通过时应尽量平行通过且不能位于断裂带内,当需要跨越断裂带时尽量垂直通过,隧道洞门边仰坡不应垂直断裂带布置;(2)选线应尽量绕避危岩落石分布广泛的地段;(3)线路宜避开断裂带,难以绕避时,应在断裂带较窄处以简易工程垂直通过,可以低矮路基、短桥矮桥等工程通过;(4)线路通过峡谷时应考虑堰塞湖、不稳定斜坡体、滑坡、岩堆、泥石流等潜在不利因素的影响,合理选择线位标高;(5)当工程毗邻的自然坡体稳定性较差,影响到工程安全时,应进行加固和绕避不稳定体的方案比选;(6)线路通过高烈度震区时尽量多设隧道,少做桥、路结构物;(7)不设或少设陡坡傍山桥、路结构物,不设或少设小半径曲线,特别是不良地质重灾群发区域。

Research purposes： The research is done on how to reasonably select railway route at very beginning of the construction for achieving the goal of scientific prevention of earthquake and reduction of disaster. Research conclusions：（ 1 ） When the railway route selection is conducted in high seismic intensity region, especially around fault zone, the track should pass through the highly intense earthquake region in parallel outside of the fault zone, and when the track has to pass through the fault zone, it should pass through the fault zone vertically as much as possible and the inverted slope around the tunnel port should not be vertical to the fault zone. （2）The railway track should keep away from the area where lots of rocks may fall in wide range. （ 3 ） The track should keep away from the fault zone as much as possible. If the track has to pass through the fault zone, it should pass the narrow area of the fault zone with low subgrade and low bridge. （4） When the track passes through valley, the reasonable track elevation should be selected on consideration to the potential unfavorable factors, such as barrier lake, unstable sliding body, sliding slope, talus and mudflow. （5） When the railway construction is conducted adjacent to the unstable slope to affect the construction safety, the comparison should be made between the plan of reinforcing the unstable slope and the plan of the track keeping away from the unstable slope. （6） When track passes through the high seismic intensity region, more tunnels should be built, and less bridge and road structure should be built. （7） No or less bridge in steep slope and near mountain, road structure and small curve radius track should be built, especially in unfavorable geological area.