【摘要】 利用动力时程法对盾构隧道进行抗震分析时,计算时间长,工作量大,土体本构以及阻尼的选择困难,不利于工程设计广泛应用。为了解决这些困难,借鉴地上结构静力推覆分析方法的思想,并结合盾构隧道的地震响应主要由周围土体的地震响应所控制的这一特点,改进了静力推覆方法中的水平加载模式,提出了适用于盾构隧道抗震分析的静力推覆分析方法,并引入了隧道倾斜度的概念来衡量隧道的抗震性能。此法通过对计算模型施加沿地层深度方向分布的倒三角侧向水平位移,来模拟地震对盾构隧道的作用,概念清楚,考虑了隧道与周围土体的相互作用,避免了在动力时程分析中所涉及的土体本构和阻尼的选择、计算模型边界条件等复杂问题,大大降低了盾构隧道抗震分析的难度,同时,可以得到隧道的抗震能力曲线。与动力时程分析的对比结果表明,在弹性阶段,此法的计算结果合理,具有较高的精度,适用于盾构隧道抗震设计。更多还原

【Abstract】 The dynamic time-history analysis of shield tunnel seismic design needs long computed time and massive work.The dynamic constitutive model and damp for soils are difficult to determine.Its wide application in practical project is hindered by these problems.In order to solve these difficulties,a modified pushover method for shield tunnel which is developed from pushover method of structure on the ground is put forward;and inclination of shield tunnel is introduced to assess its seismic performance.Since the seismic responses of shield tunnel are determined by the surrounding soils;the horizontal loading model is improved.In this method,the seismic action on shield tunnel is simulated by applying the inverted-triangular lateral horizontal displacement on the model along the depth.The complex problems existed in the dynamic time-history analysis,such as the dynamic constitutive model and damp of soil,the boundary condition,are avoided;and the interaction between tunnel and soil is able to consider in this method.The seismic performance capacity curve also could be obtained by this method.The comparison results with dynamic time-history analysis show that the calculation result of the modified pushover method is reasonable and accurate in the elastic stage.It is an appropriate method for seismic design of shield tunnel.更多还原