Twin tunnel excavations can seriously affect the integrity of buried pipelines. In this investigation, centrifuge model tests and numerical simulations were carried out to study the brittle damage of buried pipelines induced by side-by-side twin tunneling. In the numerical model, the pipelines were simulated as peridynamics (PD) shell structures, the surrounding soil was represented as a series of independent Winkler springs, and the modified Gaussian curve was incorporated as displacement-controlled boundary conditions on the springs to simulate the sequential excavation of side-by-side twin tunneling. The effectiveness of the numerical method was assessed by comparing with the centrifuge model test results. Due to the interactions of two tunnels, the fracture characteristics were more complex for twin tunneling compared with the case of single tunneling. The fracturing point induced by the second tunneling could deviate from the second tunnel centerline. The first tunneling without inducing damage can suppress the damage initiation and propagation in the pipeline under the second tunneling. A pipeline with a smaller diameter and a higher critical energy release rate in sandy soils with a lower friction angle and a shallower burial depth has a higher capacity to resist damage under twin tunneling, showing a greater initial fracture angle.

中文翻译：

---

基于离心机和数值模拟的并排双隧道埋地管道损伤分析

双隧道开挖会严重影响埋地管道的完整性。本次研究通过离心机模型试验和数值模拟，研究并排双隧道对埋地管道的脆性损伤。在数值模型中，管道被模拟为近场动力学（PD）壳结构，周围土壤被表示为一系列独立的温克勒弹簧，并结合修正高斯曲线作为弹簧上的位移控制边界条件来模拟顺序并排双隧道开挖。通过与离心机模型试验结果的比较，评估了数值方法的有效性。由于两个隧道的相互作用，双隧道的断裂特征比单隧道的情况更加复杂。第二次隧道开挖引起的破裂点可能会偏离第二隧道中心线。第一次掘进不会引起损伤，可以抑制第二次掘进下管道内损伤的萌生和扩展。直径较小、临界能量释放率较高的管道在摩擦角较小、埋深较浅的砂土中具有较高的双隧道抗损伤能力，表现出较大的初始断裂角。