Abstract This paper proposes using geofoam blocks to improve the safety of buried steel pipelines under permanent ground deformation due to strike-slip fault rupture. Since these geofoam blocks are deformable, they can compress during fault rupture and thus reduce the pressure imposed on the pipeline by the surrounding soil. This means that the pipe can sustain a higher level of tectonic deformations. For the pipeline system adopted in this study, the geofoam blocks consist of two 1 m thick blocks at each side and another on the top of the pipeline. The effectiveness of this configuration is then assessed in comparison to the conventional buried pipeline by three dimensional numerical simulations that consider the interaction between soil and structure and the impact of critical parameters such as the pipeline-fault trace crossing angle, geofoam blocks thickness and the internal pressure of the pipeline. The results indicated that the geofoam blocks reduced the axial tensile strain of non-pressurised pipeline from the unacceptable 4.16% to the safe level of 0.75% when the crossing angle was 135°. In addition, geofoam blocks successfully decreased the maximum ovalisation parameter and compressive strain of the non-pressurised pipeline from 0.237 and −25.8% to 0.065 and −0.47%, respectively when the crossing angle was 65°.

中文翻译：

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用于保护遭受走滑断层破裂的埋地管道的土工泡沫块

摘要 本文提出使用土工泡沫块来提高地下钢质管道在走滑断层破裂引起的永久地面变形下的安全性。由于这些土工泡沫块是可变形的，它们可以在断层破裂期间压缩，从而降低周围土壤对管道施加的压力。这意味着管道可以承受更高水平的构造变形。对于本研究中采用的管道系统，土工泡沫块由每边两个 1 m 厚的块和管道顶部的另一个块组成。然后通过考虑土壤和结构之间的相互作用以及关键参数（例如管道-故障轨迹交叉角）的影响的三维数值模拟，与传统埋地管道相比，评估这种配置的有效性，土工泡沫块厚度和管道的内部压力。结果表明，当交叉角为135°时，土工泡沫块将非承压管道的轴向拉伸应变从不可接受的4.16%降低到0.75%的安全水平。此外，土工泡沫块成功地将非加压管道的最大椭圆化参数和压缩应变从 0.237 和 -25.8% 分别降低到 0.065 和 -0.47%，当交叉角为 65°时。