摘要
受到非线性波浪荷载的长期作用,浅水区海底管道附近的海床极易发生局部冲刷侵蚀和输移,从而导致管道悬空失稳。为保证海底管道稳定,需要确定管道的临界悬跨长度。基于莫里森公式给出浅水区管道悬跨段所受的波浪力,根据管道最大弯曲应力与材料许用应力的关系确定临界悬跨长度。依据实际工程选取材料参数,采用Flac 3D数值计算软件分析悬跨长度、波浪要素对海底管道受力分布的影响,给出跨中弯矩修正系数k的变化规律。结果表明:悬跨情形下结构弯矩的数值解大于理论公式解,但随着悬跨长度增加,二者差值有减小趋势;跨长相同时,波高增加、波长减小或周期增长将引起管道变形量和最大弯矩的增大;随着跨长的增大,最大弯矩将向悬跨端附近迁移,说明管道的破坏点位置与跨长有关。将分析结果应用于实际案例分析,可以为悬跨管道失效判断和维护时机的确定提供依据。
Under the long-term effect of non-linear wave load,the seabed near the subsea pipeline in shallow water area is very susceptible to local scour erosion and transport,which will result in suspension and destabilization of the pipeline.To maintain the stability of subsea pipeline,the critical suspended span length of pipeline must be de⁃termined.The critical suspended span length is determined by using the wave force sustained by the suspended sec⁃tion of pipeline in shallow water area as calculated by the Morison formula and also the relation between the maxi⁃mum bending stress of pipeline and the allowable stress of the material.The material parameters are selected ac⁃cording to practical engineering,the law by which the suspended span length and wave parameter will affect the stress distribution of subsea pipeline is analyzed by using the Flac 3D numerical calculation software,and the varia⁃tion pattern of the correction factor k of mid-span bending moment is calculated.As the results indicate:the numeri⁃cal solution of the bending moment of the suspended structure is greater than the solution generated by the theoreti⁃cal formula,but as the suspended span length increases,the difference between the two solutions shows a trend of decreasing.With the same span length,the increase of wave height,decrease of wave length or increase of period will cause the deformation and maximum bending moment of pipeline to increase.As the span length increases,the maximum bending moment will move near the span end,which indicates that the failure point position of pipeline is related to the span length.The analysis result is used for analysis of practical cases,to provide the basis for identifying the failure of suspended pipeline and determining the timing of maintenance.
作者
刘成
贾贝贝
陈舒阳
孙富学
LIU Cheng;JIA Beibei;CHEN Shuyang;SUN Fuxue(College of Civil Engineering,Nanjing Forestry University,Nanjing 210037;College of Architecture and Civil Engineering,Wenzhou University,Wenzhou 325035)
出处
《现代隧道技术》
CSCD
北大核心
2024年第1期165-173,共9页
Modern Tunnelling Technology
基金
国家自然科学基金资助项目(51508278).
关键词
海底管道
波浪力
悬跨长度
Flac
3D模拟分析
Subsea pipeline
Wave force
Suspended span length
Flac 3D simulation analysis
