Public transport systems such as subway transit tunnels are prone to terrorists' bombing attacks in recent years.Segmental lining is the most common type of liners adopted with the increasing use of TBM (tunnel boring machine) in tunnel constructions in urban areas.The most apparent difference between segmental tunnel lining and an integral one lies in the existence and distribution of joints that bind several types of segments in a ring and rings in the longitudinal direction of a tunnel,which are connected by pre-stressed jointing bolts.Due to the effects of joints,the overall rigidity and loading capacity of segmental lining are relatively low,compared with that of an integral one,also the deformation and damage mechanism are different.Assuming the scenarios of internal explosion under a case of terrorist attack,few research results could be traced on the internal explosion capacity of segmental tunnel linings.In this paper,it began with the analysis of full-scale test results of segmental tunnel linings under the condition of internal explosion,the deformation and failure patterns of segmental tunnel lining were outlined,and the key factors and positions that dominate the damage of a lining were figured out.Then attempts were made,by adding flexible damping cushions on the joints,to relieve the damage degree of contact area of bolts,thus optimizing segmental lining structure's internal explosion capacity.At last,numerical simulations were performed and it was shown that,the localized failures of joint areas of tunnel segments could be relieved effectively after introduction of this method,so the internal explosion resistance performance of segmental lining structures could be optimized and hence improved.%地铁等城市隧道是恐怖爆炸袭击的主要目标之一.盾构管片隧道由不同类型的预制混凝土管片通过接头处的紧固螺栓拼装而成的.由于接头的存在,与整体式衬砌结构相比,其整体刚度和承载水平比较弱,变形和破坏机理与整体式衬砌结构不同.考虑内爆炸的恐怖袭击条件,目前关于管片隧道衬砌结构抗内爆炸的研究成果很少.从分析全尺寸管片内爆炸试验结果人手,分析了内爆炸荷载作用下管片衬砌结构变形和破坏规律,梳理出控制衬砌结构破坏的关键因素和关键位置,提出一种在接头螺栓处添加柔性垫圈来降低与螺栓接触区域管片的破坏程度的方法,以期达到优化衬砌结构抗内爆炸性能的目的.最后采用数值模拟方法,对所提出了抗爆减爆工程措施进行了分析研究.结果表明,该方法可以有效减小管环在接头处的局部破坏,提高管片衬砌的抗内爆炸性能.
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