Impacts from falling objects can pose a major risk of failure for offshore pipelines. Appropriate protection measures are required to reduce this risk. To achieve this goal, a risk-based integrity model is proposed. Based on the surrogate model of genetic programming, the finite element analysis is cooperated with the probabilistic method to consider nonlinear effects on the failure probability. The required validations are performed to demonstrate the accuracy. The cumulative prospect theory is introduced to encapsulate the risk-attitudes in the consequence evaluation. This integrated model is further extended to determine an optimal protection strategy to obtain the maximum return on an investment, as well as ensure safety of the infrastructures. A case study is used to illustrate the methodology used to determine the burial depth, which is a primary protection measure. The parametric study showed that the soil property and pipeline wall thickness have a considerable influence on the risk. A comprehensive overview of the outputs from different risk-attitudes is also provided. This study can provide a reference for offshore pipeline safety design, and the proposed model can be used as a potential guideline for other researchers to develop customised risk assessment models.

掉落物体的冲击可能会给海上管道带来重大的故障风险。需要采取适当的保护措施以减少这种风险。为了实现这一目标，提出了一种基于风险的完整性模型。基于遗传规划的替代模型，将有限元分析与概率方法相结合，以考虑非线性对失效概率的影响。执行所需的验证以证明准确性。引入累积前景理论以在结果评估中封装风险态度。进一步扩展了该集成模型，以确定最佳保护策略，以获得最大的投资回报，并确保基础架构的安全。通过案例研究来说明确定埋葬深度的方法，这是主要的保护措施。参数研究表明，土壤性质和管道壁厚对风险有相当大的影响。还提供了来自不同风险态度的输出的全面概述。这项研究可以为海上管道安全设计提供参考，并且该模型可以用作其他研究人员开发定制风险评估模型的潜在指南。