第三方活动冲击荷载作用下近海管道损伤机理及风险评估研究现状

平台坠物、船舶抛锚等第三方活动引起的冲击损伤是近海管道失效的主要原因，时刻威胁中国海洋油气开发系统的安全性。为保障近海油气管道安全运行，围绕冲击荷载作用下管道损伤及失效评估这一中心问题，从管道损伤机理研究、含冲击损伤管道安全评估、管道工程项目风险评估3个方面总结了国内外研究发展现状，明确了影响结构安全的关键问题，并对未来研究工作提出建议。挖沟埋深为管道防护冲击损伤的有效手段，土体强度是防护效果关键因素，应重点关注土体强度空间变异性问题；管道冲击损伤主要为平滑凹陷和弯折凹陷，对于后者应进一步确定其在内压荷载下的剩余强度及疲劳强度；风险评估中失效判据对于结果有显著影响，需构建考虑多种安全性评估准则的失效判据体系。

A review on the damage mechanism analysis and risk assessment for offshore pipelines subjected to impact loads from third-party activities

Impact damage caused by third-party activities of dropped objects from platform operation and ship anchoring is the primary cause for offshore pipeline failures, which threatens the safety of offshore oil and gas exploitation system. Aiming at the research on damage and failure risk assessment for offshore pipelines subjected to impact loads, the state of arts of the relevant studies from three aspects was reviewed, including the damage mechanism analysis, safety evaluation of the damaged pipelines, and risk assessment. The influential factors on structural safety were identified, and the future research work was recommended. It is shown that: trench and burial are an effective practice in providing shelters for pipelines from impact damage, and soil strength is the dominant factor that influences the protection efficiency. Further studies should concern the natural characteristic of the spatial variabilities for soil strength, which influences the soil failure modes and the damage extent for pipelines. Damages for impacted pipelines can be classified into two categories, plain dent and folded dent. For the latter, the residual strength and fatigue strength subjected to internal pressures remain to be further evaluated to achieve a reliable safety assessment. For the risk assessment, the failure criterion proves to have a significant impact on the results. Thus, it is highly recommended to develop a failure criterion system, that considers multiple safety evaluation criterions for various categories of pipeline damages of the potential scenarios.