板锚在双层黏土中埋深损失的大变形有限元分析  

Large Deformation Finite Element Analysis on Buried Depth Loss of Plate Anchors in Double‑layer Clay

作　　者：高鹏 张雷克[1] 赵燕兵 GAO Peng;ZHANG Leike;ZHAO Yanbing(College of Water Resources Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学水利科学与工程学院,山西太原030024

出　　处：《防灾减灾工程学报》2023年第4期658-665,673,共9页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(51741909);山西省应用基础研究计划项目(201901D211020)资助。

摘　　要：海洋工程中,海床土体分层现象对吸力嵌入式板锚(SEPLA)在海床中的旋转调节过程有着不可忽视的影响。基于耦合的欧拉‑拉格朗日(CEL)法,建立起用于分析板锚在双层黏土中埋深损失的有限元模型。通过与已有离心机试验及数值计算结果对比,验证模型的有效性。在板锚初始埋深不变的情况下,考察不同系缆点距上下层土体分界线距离(d)及强度比(s_(u1)/s_(u2))对板锚在双层黏土中埋深损失的影响,通过分析板锚周围土体的流动机制,明确了锚在双层黏土中埋深损失增大的原因,并建立起板锚埋深损失经验公式。结果表明,在s_(u1)/s_(u2)<1的双层黏土中,随着d的增大,板锚的埋深损失先增大后减小,并存在一极大值ΔZ_(max),该极值比板锚在下层均质土中埋深损失大74.2%-81.1%,在工程中较为危险;在s_(u1)/s_(u2)>1的双层黏土中,随着d的增大,板锚的埋深损失逐渐减小;d≤-0.5B与d≥1B时,板锚的旋转过程分别仅受上层土体与下层土体的影响。In offshore engineering,the stratification of seabed soil has an important influence on the keying process of suction embedded plate anchor(SEPLA)in the seabed.Based on the coupled Eulerian-Lagrangian(CEL)method,the finite element analysis model is established for analyzing the embedment loss of plate anchors.By comparing the results of the centrifuge test and numerical method,the efficiency of the finite element model is verified.With the same initial buried depth,the embedment loss of plate anchors is analyzed considering the influences of the distance between the shackle and the soil boundary(d)and the strengths ratio of the overlying soil to the underlying soil(s_(u1)/s_(u2)).By analyzing the soil flow mechanism around plate anchors,the reason for the increase of embedment loss is identified.In addition,an empirical formula is established for the embedment loss of plate anchors.It concludes that for the double-layer clay of s_(u1)/s_(u2)<1,the buried depth of the anchor increases and then decreases as the value of d increases,and there exists a maximum value of ΔZ_(max),which is 74.2%~81.1%larger than the embedment loss of the anchor in the uniform soil,indicating a more dangerous situation in the engineering practice.For the double-layer clay of s_(u1)/s_(u2)>1,the buried depth of the anchor decreases as the value of d increases.For d≤-0.5B and d≥1B,the keying of plate anchors is only affected by the overlying and underlying soil,respectively.

关 键 词：双层黏土 板锚 埋深损失 大变形有限元 经验公式 

分 类 号：P751[交通运输工程—港口、海岸及近海工程]