穿越活动断裂带铁路隧道抗震关键技术

震害统计结果表明，当隧道穿越活动断裂带段时，结构震损尤为严重，尤其是位错量达到m级时，仅靠结构自身难以抵抗。为建立穿越活动断裂带铁路隧道抗震技术体系，通过现场调查对大梁隧道震害特征进行分析，采用模型试验及数值模拟方法研究穿越活动断裂带隧道变形破坏机制。研究表明： 1）现有铁路隧道抗震技术及工程措施可保证洞口、浅埋及洞身非活动断裂带段的隧道结构在地震作用下保持结构稳定，但目前尚无可靠的隧道结构形式可以抵抗大尺度位错。2）基于震害调查结果，通过理论分析提出穿越活动断裂带隧道设防分区。3）穿越活动断裂带隧道的破坏主要集中在强烈影响段及其两侧一般影响段，应针对2种区段的不同震害机制分别进行抗震设防。4）通过理论分析及文献调研，提出穿越活动断裂带隧道新型多级减震可变结构设计体系、隧道震后快速抢通方案。

Key Technology of Anti Seismic for Railway TunnelsCrossing Active Fault Zone

The existing statistics show that serious damages caused by shear strength during earthquake will appear when tunnels cross active fault zones. The tunnel structures cannot withstand large dislocations (over 1 m). Accordingly, to establish a key technology system of railway tunnels crossing active fault zones, the seismic damage characteristics of Daliang tunnel are analyzed through field investigation, and the deformation and failure mechanism of tunnel crossing active fault zone are examined by model test and numerical simulation. The results show that: (1)The existing anti seismic technology and engineering measures adopted for railway tunnels can guarantee the stability of tunnel structures in the portal, shallowly buried, and inactive fault zone sections during an earthquake, but there is not reliable tunnel structure can withstand large scale (meter level) dislocations. (2)Based on the results of earthquake damage investigation, the fortification zones of tunnels crossing the active fault zone are proposed through theoretical analysis. (3)The damage of tunnels crossing the active fault zone primarily concentrates on areas severely and generally impacted by the active fault dislocation, so fortification should be employed separately according to the different earthquake damage mechanisms. (4)Based on theoretical analyses and literature researches, a new multi stage shock absorbing structure and a rapid recovery plan are proposed for the railway tunnels cross the active fault zone.