Adaptability analysis and evaluation system for directional drilling of submarine pipelines crossing soil layers

To address construction risks posed by complex soil-structure interactions and dynamic marine conditions during horizontal directional drilling (HDD) of submarine pipelines, this study proposes a geotechnical adaptability evaluation system, driven by multi-source data and optimised using intelligent algorithms. Marine environmental data including ocean current velocity and wave height are acquired via marine sensors, while geotechnical instruments provide critical subsurface data on soil mechanical properties and stratigraphy. These datasets are consolidated into a unified real-time database to support coupled analysis. A multi-physics simulation model is established to assess soil layer suitability, predict pipeline mechanical behaviour, and evaluate casing vibration throughout the HDD process. Key construction parameters such as mud viscosity, borehole pressure, and pipeline stress gradients are dynamically optimised within a closed-loop framework using a modified adaptive genetic algorithm, facilitating accurate prediction and process regulation. The system was validated on the Huangzeshan-Yushan submarine crude oil pipeline project in Zhoushan, China. Field application yielded significant improvements: borehole collapse incidents were reduced by 70%, pullback failures by 81%, and pipe sticking events by 83%. Moreover, safety factors in critical zones improved by over 15%, mud reuse exceeded 74%, project duration was shortened by 26.5%, and total costs decreased by 34.5%. These results demonstrate that the system improves safety, efficiency, and cost-effectiveness in complex submarine pipeline construction, while offering scientific decision support for related engineering applications.