The paper presents a combined experimental and numerical investigation of the bending response of lap welded joints in pressurized steel water pipelines. It is motivated by the structural performance of large-diameter steel pipelines used for water transmission in seismic and geohazard areas, where the pipeline may be subjected to severe permanent ground-induced actions. A series of large-scale four-point bending experiments on lap welded joints has been performed, and rigorous finite element numerical models have been developed for conducting extensive numerical simulations. The numerical models account for the bell forming process and the corresponding residual stresses, as well as the presence of initial geometric imperfections on the pipeline wall. A very good comparison has been found between experimental results and numerical simulations in terms of both global response and local strains developed at the vicinity of the weld. The finite element models are also employed for elucidating some interesting features of lap welded joint behavior under severe bending deformation, towards determining the joint strength, its deformation capacity and the evolution of strain at different deformation stages. The experimental and numerical results indicate that lap welded joints, can sustain a significant level of bending deformation and strain, without loss of pressure containment, and can be used in geohazard areas, where severe permanent ground-induced strains on the pipeline wall are expected to develop.

本文对钢制输水管道中搭接接头的弯曲响应进行了实验和数值研究的组合。它是受地震和地质灾害地区用于输水的大口径钢管的结构性能影响的，在这些地区，钢管可能会遭受严重的永久性地面诱发作用。在搭接焊缝上进行了一系列大规模的四点弯曲实验，并开发了严格的有限元数值模型来进行广泛的数值模拟。数值模型考虑了钟形成型过程和相应的残余应力，以及管道壁上存在初始几何缺陷。在整体响应和焊缝附近产生的局部应变方面，已经在实验结果和数值模拟之间找到了很好的比较。有限元模型还用于阐明搭接焊接接头在严重弯曲变形下的一些有趣特征，以确定接头强度，变形能力和不同变形阶段的应变演化。实验和数值结果表明，搭接焊接接头可承受较大程度的弯曲变形和应变，而不会损失压力，并且可用于地质灾害区域，在该区域中，地面上预计会出现严重的地面永久应变。开发。有限元模型还用于阐明搭接焊接接头在严重弯曲变形下的一些有趣特征，以确定接头强度，变形能力和不同变形阶段的应变演化。实验和数值结果表明，搭接焊接接头可承受较大程度的弯曲变形和应变，而不会损失压力，并且可用于地质灾害区域，在该区域中，预计在地面上管道壁会产生严重的永久性地面应变。开发。有限元模型还用于阐明搭接焊接接头在严重弯曲变形下的一些有趣特征，以确定接头强度，变形能力和不同变形阶段的应变演化。实验和数值结果表明，搭接焊接接头可承受较大程度的弯曲变形和应变，而不会损失压力，并且可用于地质灾害区域，在该区域中，预计在地面上管道壁会产生严重的永久性地面应变。开发。