ISSN 1000-3665 CN 11-2202/P

    考虑颗粒破碎的砂土中鱼雷锚贯入离散元分析

    Discrete element analysis of torpedo anchor penetration into calcareous sands considering particle breakage

    • 摘要: 鱼雷锚作为一种新型深海锚固装置,在海洋油气开发等工程中应用广泛,但目前关于钙质砂海床中鱼雷锚贯入特性的研究较为匮乏。基于离散元方法,对钙质砂地基中的鱼雷锚贯入过程进行了数值分析,通过与已有室内试验结果的对比验证了数值模型的可靠性,数值模拟重点分析了鱼雷锚贯入过程中锚周土体颗粒破碎的演化规律及其对锚体贯入特性的宏细观影响。结果表明:在鱼雷锚贯入过程中,锚尖及锚端周围土体破碎严重,锚侧颗粒破碎相对较弱,颗粒破碎数量随着贯入深度的增加而增加;颗粒速度场分布基于锚体中心轴基本对称,随着贯入深度的增加,颗粒速度场分布范围扩大,颗粒运动速度峰值在贯入过程中先增加后下降;随着贯入深度增加,应力峰值先增加后逐渐减少,在翼板开始接触土体后,应力峰值达到最大值。研究结果可为岛礁工程动力锚贯入设计提供参考。

       

      Abstract: As a new type of deep-sea anchorage device, the torpedo anchor is widely used in deep-sea oil and gas exploitation projects, but few attentions have been paid to the torpedo anchor penetrating into coral deposits. Based on the discrete element method, the penetration process of torpedo anchor into calcareous sands is numerically analyzed. The reliability of the numerical model is verified by comparing with the existing indoor test results. The numerical simulation focuses on the evolution of particle breakage of soils around the anchor during the penetration process, and its macro and micro effects on the anchor penetration characteristics are also discussed. The results show that in the process of torpedo anchor penetration, the soil around the anchor tip is seriously broken, while the particle breakage at the anchor side is relatively weak. The particle breakage quantity increases with the increase of penetration depth, and the distribution of particle velocity field is basically symmetrical along the central axis of the anchor body. With the increase of penetration depth, the distribution range of particle velocity field expands, and the peak particle velocity first increases and then decreases during the penetration process. The peak value in the stress concentration area first increases and then decreases, when the penetration depth increases. After the flange starts to contact the soil, the stress within the soil reaches the maximum. The research results can provide references for the design of dynamic anchor penetration in island and reef engineering.

       

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