海底管线整体屈曲过程中土体水平向阻力模型研究  

A soil resistance model for subsea pipeline global lateral buckling analysis

作　　者：刘润[1] 刘文彬[1,2] 洪兆徽 王乐[1] 

机构地区：[1]天津大学水利工程仿真与安全国家重点试验室,天津300072 [2]中交天津港湾工程研究院有限公司,天津300222

出　　处：《岩土力学》2015年第9期2433-2441,共9页Rock and Soil Mechanics

基　　金：国家重点基础研究发展计划(No.2014CB046800);国家自然科学基金优秀青年基金(No.51322904);高等学校博士学科点专项科研基金资助课题(No.2013032110074)

摘　　要：高温、高压作用下不埋或浅埋的海底管线较易发生水平向整体屈曲,土体对管线的阻力决定了管线的变形形态及变形后的应力状态,因此,确定管线受到的土体阻力对准确地分析管线的整体屈曲有重要意义。开展了基于渤海砂性土体的系列室内模型试验,测定了不同埋深条件下管线受到的土体阻力,建立了随埋深条件而变化的土体动态阻力模型,揭示了埋深对土体阻力峰值和最终稳定值的影响。由于ABAQUS内置的罚函数接触模型无法实现管-土界面的动态摩擦特性,开发了子程序VFRIC,在管线温-压联合作用下的整体屈曲分析中成功引入了建立的土体动态阻力模型,实现了土体阻力大小与管线位移相关的动态接触特性模拟,从而较为真实地反映了管线整体屈曲过程中受到的土体阻力变化过程。研究表明,不同土体阻力模型对管线整体屈曲分析结果影响显著,在动态阻力模型中由于土体阻力存在峰值和衰减过程,因此计算得到的管线整体屈曲临界轴力明显提高,管线屈曲变形更为集中,最大弯矩和应变也相应增大。High temperature and high pressure can lead to a lateral global buckling of unburied or shallowly buried submarine pipelines. Because soil resistance determines the deformation and stress distribution of post-buckling pipelines, it is important to characterize the soil resistance in the pipeline global buckling analysis. A series of model tests based on the sand sampled from Bohai Gulf is conducted. The soil resistance to pipelir^es with different buried depths are measured. A dynamical soil resistance model varying with the buried depth of pipeline is developed, and the influence of buried depth on peak soil resistance and final soil resistance is analyzed. As the built-in penalty interaction model in ABAQUS software cannot simulate the dynamical friction in pipe-soil interaction, a user-defined subroutine VFRIC is developed to implement the established soil resistance model and used to simulate the variation of soil resistance with pipeline displacement for accurate pipeline global buckling analysis. The study shows that the soil resistance model can significantly affect the results of post-buckling pipeline. Because the dynamical soil resistance model has a peak value and an attenuation process, the critical buckling force of post-buckling pipelines with dynamical soil resistance model is larger than pipeline with constant soil resistance, the deformation of post-buclding pipelines with dynamical soil resistance model is more concentrated, and the maximum bending moment and strain are larger.

关 键 词：海底管线 水平向整体屈曲 土体阻力模型 ABAQUS二次开发 子程序VFRIC 

分 类 号：TU411[建筑科学—岩土工程]