活动断裂区域隧道工程震后修复关键技术研究

Key Techniques and Countermeasures for Tunnel Repair Projects after Earthquake while Tunneling through Active Faults

研究目的:针对近年来强震对地下工程造成的安全影响,通过实际案例剖析,明确震害类型并提出震后隧道结构安全评估方法,明确地震引起的结构破坏范围及其程度,提出围岩劣化条件下衬砌结构抗震验算思路,提出灾后隧道修复或结构补强方法,进一步从衬砌结构设计方面,提出增强隧道韧性适应大变形地层位错能力的措施。研究结论:(1)提出了活动断裂区域隧道震害三种形式,建立了隧道震害评估方法,明确结构型震害与变形型震害的分级原则;(2)基于地震引起围岩劣化与地震烈度提高,提出隧道抗震验算分析方法,明确具体抗震薄弱区域;(3)明确震后隧道整体修复方案,包含洞身临时加固方案与衬砌结构永久补强方案;(4)基于常用隧道抗错断措施存在的缺陷,从衬砌类型选择、仰拱结构与新型节段式衬砌等方面,提出更为有效的应对地层大变形需求的抗错断措施;(5)本研究成果可为震后地下工程的评估与修复提供参考。

Research purposes:As for the safety influences on underground engineering after strong earthquake,the safety assessment method for tunnel structure was put forward based on case analysis.The scope and extent of structural damage caused by earthquake was identified,and the seismic calculation method of lining structure after the degradation of surrounding rock was presented and the tunnel renovation and structural reinforcement were proposed correspondingly.Finally,the enhance measures for tunnel adaptability of large stratum deformation were put forward in terms of the design of the second lining.Research conclusions:(1)The assessment method for tunnel hazard induced by earthquake in active fault was established.The classification principle of structural and deformation type earthquake damage was made.(2)Based on the degradation of surrounding rock and the increase of earthquake intense,the seismic analysis of tunnel and the specific seismic weak area were put forward correspondingly.(3)The overall tunnel renovation method afer earthquake was proposed,including the temporary reinforcement method for tunnel body and the permanent reinforcement of tunnel lining.(4)Considering the defect of anti-fault measures in common,based on the selection of lining type,arch structure,new type of segmental lining and so on,the more effective anti-fault measures to meet the large stratum deformation were put forward.(5)The research results can serve as references for the evaluation and repair of underground engineering after earthquake.