钻井船插桩对邻近平台桩基影响的数值分析

发布时间：2018-06-20 05:29

本文选题：钻井船插桩 + 邻近桩　；参考：《天津大学》2014年硕士论文

【摘要】：自升式钻井船在海洋油气勘探中运用广泛,当钻井船在导管架固定平台附近插桩作业时,会不可避免的对邻近平台的桩基稳定产生不利影响,有必要对钻井船桩靴贯入对邻近平台桩基产生的影响进行分析评价。本文对钻井船插桩对邻近平台桩影响的问题进行了研究。首先运用耦合的欧拉-拉格朗日(CEL)方法模拟了钻井船插桩过程,并将桩靴受到的插桩阻力与SNAME规范求得的插桩阻力解对比,探讨CEL方法在模拟钻井船插桩问题的可行性,结果表明:CEL方法的插桩阻力计算结果和SNAME计算得到的插桩阻力解较为接近,且能反映出泥面土体隆起,土体回淤等土体运动的实际现象。其次分析了CEL有限元模型中不同计算参数取值对钻井船桩靴受到的插桩阻力计算结果的影响。结果表明:不同欧拉体深度和桩靴与土体之间摩擦系数取值对CEL有限元计算结果的影响较小;不同插桩速率对CEL有限元计算结果的影响较大;插桩过程需要考虑土体重力的影响。然后利用CEL方法对钻井船插桩对不同桩头约束条件下受影响桩的影响进行分析,通过与离心模型试验结果进行对比,验证了该方法的可行性。并针对钻井船插桩对邻近桩影响的问题,对欧拉体的设置范围对计算结果的影响进行了研究,结果表明:(1)在插桩对邻近固定桩头受影响桩的CEL有限元分析中,若插桩深度小于0.75倍桩靴直径,可将欧拉土体范围设置成插桩深度以下1-1.25倍桩靴直径;若插桩深度大于0.75倍桩靴直径,将欧拉土体范围取为插桩深度以下0.5倍桩靴直径是恰当的。(2)在插桩对邻近自由桩头受影响桩的CEL有限元分析中,若插桩深度小于0.5倍桩靴直径,可以将欧拉土体的范围设置为泥面以下1.5-2.5倍桩靴直径;若插桩深度大于0.5倍桩靴直径,将插桩深度与插桩深度以下0.5-1倍桩靴直径范围内的土体均设置成欧拉土体较为合理。最后,运用修正的应变路径法并结合地基反力法可以对钻井船插桩对邻近桩的影响进行分析,结果表明:这种理论简化方法计算结果较离心模型试验结果偏于保守,只能定性的进行分析。
[Abstract]:The jack up drilling ship is widely used in the offshore oil and gas exploration. When the drilling ship is inserted near the fixed platform of the jacket, it will inevitably have an adverse effect on the stability of the pile foundation of the adjacent platform. It is necessary to analyze and evaluate the effect of the penetration of the pile boots on the pile foundation of the adjacent platform. The problem of the influence of the near platform pile is studied. First, the coupled Euler Lagrange (CEL) method is used to simulate the pile driving process of the drilling ship, and the feasibility of the CEL method in simulating the drilling of the drilling vessel is discussed. The results show that the plug resistance of the CEL method is proved to be the resistance of the plugged pile in the CEL method. The calculation results are close to that obtained by the SNAME calculation, and it can reflect the actual phenomena of soil movement such as soil uplift and siltation of soil. Secondly, the influence of different calculation parameters in the CEL finite element model on the calculation results of pile drag resistance of the drilling ship is analyzed. The results show that the depth of different Eulerian body and the depth of the Euler body are different. The coefficient of friction coefficient between pile boots and soil has little influence on the results of CEL finite element calculation; different inserting pile speeds have great influence on the results of CEL finite element calculation; the influence of soil gravity is considered in the pile insertion process. Then, the influence of the drilling ship inserting pile on the affected pile under the constraints of different pile heads is analyzed by using the CEL method. Compared with the centrifuge model test results, the feasibility of the method is verified. The effect of the setting range of the Euler body on the calculation results is studied. The results show that (1) the depth of the inserted pile is less than 0.75 in the CEL finite element analysis of the adjacent fixed pile head receiving the shadow pile. The diameter of a double pile shoe can be set to the diameter of the 1-1.25 double pile shoe diameter below the depth of the pile. If the depth of the pile is greater than 0.75 times the diameter of the pile boots, it is appropriate to take the Eulerian soil range to 0.5 times the diameter of the pile shoe below the pile depth. (2) in the CEL finite element analysis of the adjacent free pile head, the depth of the plug is less than 0.. 5 times the diameter of the pile shoe, the range of the Euler soil can be set to 1.5-2.5 times the diameter of the pile shoe below the surface of the mud. If the depth of the pile is greater than 0.5 times the diameter of the pile boots, the soil of the soil in the diameter of the 0.5-1 times of the pile shoe diameter below the depth of the pile is more reasonable. Finally, the modified strain path method is used to combine the foundation inverse method. The force method can be used to analyze the influence of the drilling vessel inserting pile on the adjacent pile. The results show that the calculation results of this theoretical simplified method are more conservative than the centrifugal model test results, and can only be analyzed qualitatively.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1

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