Abstract The shield tunneling above an existing line has been a commonly encountered problem in urban construction in recent years. It is obvious that the over-crossing tunneling will adversely affect and even damage the existing tunnels if the induced deformation exceeds the design limit of tunnel structures. In order to obtain a better understanding of the effects of the above-crossing tunneling on the existing tunnels and provide a quick and effective tool for evaluating the behaviors of underlying tunnels prior to construction, in this study a simplified analytical method is proposed. In this model, the tunnel is represented by a series of short beams resting on a Winkler foundation connected by tensile springs, compressional springs and shear springs, so that the rotational effect and shearing effect of the joints between lining rings can be captured. Our new model is compared with some existing models, such as Euler–Bernoulli beam and a series of short beams connected only by shear springs, by comparing their predictions with the field-measured longitudinal deformation of two Shanghai subway tunnels. Results of these case studies show that the predictions of our model are much closer to field monitored data than those existing models. In addition, a parametric analysis is also conducted to investigate the influences of the different factors, including advancing distance, clearance distance and stiffness of joints, on the behaviors of the existing tunnels.

中文翻译：

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上穿盾构隧道引起既有隧道响应的解析解

摘要 既有线路上盾构隧道施工是近年来城市建设中普遍遇到的问题。显然，如果超跨隧道施工引起的变形超过隧道结构的设计极限，将对既有隧道产生不利影响，甚至破坏。为了更好地了解上穿隧道对既有隧道的影响，并为在施工前评估下伏隧道的行为提供一种快速有效的工具，本研究提出了一种简化的分析方法。在这个模型中，隧道由一系列短梁代表，这些短梁搁在 Winkler 基础上，由拉伸弹簧、压缩弹簧和剪切弹簧连接，从而可以捕捉衬环之间接头的旋转效应和剪切效应。我们的新模型与一些现有模型进行了比较，例如欧拉-伯努利梁和一系列仅由剪切弹簧连接的短梁，通过将它们的预测与两条上海地铁隧道的现场测量纵向变形进行比较。这些案例研究的结果表明，与现有模型相比，我们模型的预测更接近现场监测数据。此外，还进行了参数分析，研究了前进距离、净空距离和节点刚度等不同因素对既有隧道行为的影响。例如欧拉-伯努利梁和一系列仅由剪切弹簧连接的短梁，通过将它们的预测与上海两条地铁隧道的现场测量纵向变形进行比较。这些案例研究的结果表明，与现有模型相比，我们模型的预测更接近现场监测数据。此外，还进行了参数分析，研究了前进距离、净空距离和节点刚度等不同因素对既有隧道行为的影响。例如欧拉-伯努利梁和一系列仅由剪切弹簧连接的短梁，通过将它们的预测与上海两条地铁隧道的现场测量纵向变形进行比较。这些案例研究的结果表明，与现有模型相比，我们模型的预测更接近现场监测数据。此外，还进行了参数分析，研究了前进距离、净空距离和节点刚度等不同因素对既有隧道行为的影响。