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近海海底管线会在港口锚地处因船舶走锚而受到损害,碎石结构能够防护管线免受走锚的危害,因此研究碎石结构的防护机理对保护管线有重要意义。采用极限平衡方法分析了走锚状态下土楔对形状复杂的商用霍尔锚的作用力,提出了锚冠和锚爪的受力计算模式,采用3种不同几何相似比的模型锚在模型槽中进行了拖锚试验。模型试验的结果与计算结果相互吻合。锚体整体受力分析的结果表明,霍尔锚在从砂土进入碎石保护层后因力矩不平衡引起锚体翻转,使锚爪尖位置上移而远离埋设的管线,从而使管线避免走锚的伤害。该机理也通过模型试验得到验证。此外,不同试验锚重的归一化结果还说明,霍尔锚锚爪在碎石中的稳定入土深度约为爪长的0.45,拖曳力为2.5倍锚重,可为碎石结构设计参考。
Offshore seabed pipelines will be harmed by anchorage in the port because of the ship’s anchorage. The gravel structure can protect the pipeline from the danger of going to the anchor. Therefore, it is of great significance to study the protection mechanism of the gravel structure to protect the pipeline. The limit equilibrium method is used to analyze the force of the earth wedge on the complex shape of the commercial Hall anchor under the condition of the anchor. The force calculation model of the anchor crown and the anchor jaw is proposed. Three kinds of model anchors with different geometric similarity ratios In the drag anchor test. The results of the model test are consistent with the calculated results. The results of the overall stress analysis of the anchor body show that when the anchor bolt enters the gravel protective layer from the sand soil, the anchor body is reversed due to the moment imbalance, and the position of the anchor claw tip is moved away from the buried pipeline so as to prevent the pipeline from walking s damage. The mechanism is also verified by model tests. In addition, the normalized results of different experimental anchors also show that the stable anchoring capacity of Hall anchors in gravel is about 0.45 for the claw length and 2.5 times for the towing force, which can be used as a reference for the gravel structure design.