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盾构隧道衬砌由于各种类型接头的存在而与整体式衬砌的力学特性存在较大差异。将盾构隧道衬砌结构看作由弹塑性铰链连接的刚性管片组成,考虑围岩介质的黏弹性,提出了爆炸地震波作用下盾构隧道动力分析的简化计算方法。采用该方法对南京地铁盾构段典型横断面进行了动力分析,研究了爆炸地震波入射角度、围岩介质特性及管片厚度对结构受力与变形的影响规律。分析结果表明:波入射角度对盾构隧道有很大影响,斜入射时结构的动力响应要大于垂直入射时结构的动力响应;围岩介质等级越高,围岩对隧道结构的约束越强,隧道的抗爆性能越好;管片厚度的增大会增大结构的内力,合理设置管片厚度有利于提高盾构隧道抗爆性能。
Shield tunnel lining due to the existence of various types of joints with the mechanical properties of the overall lining there is a big difference. Taking the shield tunnel lining structure as the rigid segment connected by elastic-plastic hinges, considering the viscoelasticity of the surrounding rock medium, a simplified calculation method for the shield tunnel dynamic analysis under the blasting seismic wave is proposed. This method is used to analyze the typical cross-section of Nanjing subway shield section, and the effects of blasting seismic wave incident angle, surrounding rock properties and the thickness of the slab on the stress and deformation of the structure are studied. The results show that the angle of incident wave has a great influence on the shield tunnel and the dynamic response of the structure is greater than that of the normal incident beam. The higher the surrounding rock grade, the stronger the constraint of the surrounding rock to the tunnel structure, The better antiknock performance of tunnel is. The increase of the thickness of the pipe will increase the internal force of the structure. The reasonable thickness of the pipe will help improve the antiknock performance of the shield tunnel.