This study first explores the impact on adjacent structures caused by a shield-machinebored tunnel in loose sand; observed displacements of structures have been reported that have rarely been examined in the past. Further, considering the difficulty of the reasonable prediction in advance of the ground convergence during tunnelling, a new method for the numerical investigation of the three-dimensional deformations induced by a tunnel in said ground conditions is developed, which is associated with the properties of backfill grout and pressure in the grouting zone, and a hardening soil-small strain model is selected for the simulation of soil behaviors. The influences on the ground deformations caused by changes in the operation parameters, such as the face and backfill grouting pressure as well as the elastic modulus of the backfill grout, are also explored. Finally, the strain level of the soil caused by tunnelling is examined and compared with the results from previous works, and a detailed discussion is provided.

中文翻译：

---

散沙中盾构掘进隧道三维性能的数值研究

这项研究首先探讨了散砂中的盾构机掘进隧道对相邻结构的影响。据报道，过去观察到的结构位移很少被检查。此外，考虑到隧道施工过程中地面收敛之前难以进行合理预测的困难，开发了一种新的数值研究隧道在所述地面条件下引起的三维变形的方法，该方法与回填的性质有关在灌浆区灌浆和施加压力，并选择一个硬化土-小应变模型来模拟土的行为。由于工作参数的变化（例如面层和回填注浆压力以及回填浆液的弹性模量）对地面变形的影响，也进行了探索。最后，研究了隧道引起的土壤应变水平，并将其与以前的工作结果进行了比较，并提供了详细的讨论。