Wave-soil-pipe coupling effect on the untrenched pipeline stability on sands is for the first time investigated experimentally. Tests are conducted in the U-shaped water tunnel, which generates an oscillatory how, sim...Wave-soil-pipe coupling effect on the untrenched pipeline stability on sands is for the first time investigated experimentally. Tests are conducted in the U-shaped water tunnel, which generates an oscillatory how, simulating the water particle movements with periodically changing direction under the wave action. Characteristic times and phases during the instability process are revealed. Linear relationship between Froude number and non-dimensional pipe weight is obtained. Effects of initial embedment and loading history are observed. Test results between the wavesoil-pipe interaction and pipe-soil interaction under cyclic mechanical loading are compared. The mechanism is briefly discussed. For applying in the practical design, more extensive and systematic investigations are needed.展开更多
深海管线通常铺设于海床表面,在自重和铺管作业的影响下会嵌入海床,其嵌入深度w_(ini)显著影响海床对管线的侧向土阻力。现有研究多聚焦于嵌入深度较浅情况(w_(ini)=0.1D~0.5D,D为管径),而最新调查表明,部分管线嵌入深度已超过0.5D。为...深海管线通常铺设于海床表面,在自重和铺管作业的影响下会嵌入海床,其嵌入深度w_(ini)显著影响海床对管线的侧向土阻力。现有研究多聚焦于嵌入深度较浅情况(w_(ini)=0.1D~0.5D,D为管径),而最新调查表明,部分管线嵌入深度已超过0.5D。为揭示更大嵌入深度下管-土相互作用机制,采用径向基点插值法-网格重剖分和小应变插值技术(radial point interpolation method-remeshing and interpolation technique with small strain,简称RPIM-RITSS)数值方法,对嵌入深度为0.1D~1.0D的管线开展了管-土侧向相互作用大变形数值分析。通过与已有相关离心机试验及数值结果对比,验证了该数值方法的有效性。在此基础上,深入分析了管线嵌入深度和重量对其侧向屈曲模式和土阻力的影响,据此提出了适用于嵌入深度为0.6D~1.0D的残余侧向屈曲土阻力预测模型,以期为深海管线的侧向稳定性和安全评估提供参考。展开更多
基金The project supported by the National Natural Science Foundation of China (19772057,19772065) and by the Chinese Academy of Sciences (KZ951-A1-405-01)
文摘Wave-soil-pipe coupling effect on the untrenched pipeline stability on sands is for the first time investigated experimentally. Tests are conducted in the U-shaped water tunnel, which generates an oscillatory how, simulating the water particle movements with periodically changing direction under the wave action. Characteristic times and phases during the instability process are revealed. Linear relationship between Froude number and non-dimensional pipe weight is obtained. Effects of initial embedment and loading history are observed. Test results between the wavesoil-pipe interaction and pipe-soil interaction under cyclic mechanical loading are compared. The mechanism is briefly discussed. For applying in the practical design, more extensive and systematic investigations are needed.
文摘深海管线通常铺设于海床表面,在自重和铺管作业的影响下会嵌入海床,其嵌入深度w_(ini)显著影响海床对管线的侧向土阻力。现有研究多聚焦于嵌入深度较浅情况(w_(ini)=0.1D~0.5D,D为管径),而最新调查表明,部分管线嵌入深度已超过0.5D。为揭示更大嵌入深度下管-土相互作用机制,采用径向基点插值法-网格重剖分和小应变插值技术(radial point interpolation method-remeshing and interpolation technique with small strain,简称RPIM-RITSS)数值方法,对嵌入深度为0.1D~1.0D的管线开展了管-土侧向相互作用大变形数值分析。通过与已有相关离心机试验及数值结果对比,验证了该数值方法的有效性。在此基础上,深入分析了管线嵌入深度和重量对其侧向屈曲模式和土阻力的影响,据此提出了适用于嵌入深度为0.6D~1.0D的残余侧向屈曲土阻力预测模型,以期为深海管线的侧向稳定性和安全评估提供参考。
