松砂中螺旋锚上拔承载力及破坏模式数值分析  

Numerical Analysis of the Uplift Capacity and the Failure Mode of Helical Anchors In Loose Sand

作　　者：袁驰 张新 郝冬雪[1] 陈榕[1] 

机构地区：[1]东北电力大学建筑工程学院

出　　处：《东北电力大学学报》2019年第6期50-57,共8页Journal of Northeast Electric Power University

基　　金：吉林省科技厅优秀青年人才基金项目(20170520105JH)

摘　　要：基于ABAQUS有限元软件,采用耦合欧拉拉格朗日法处理大变形问题,模拟松砂中锚板直径D=0.4 m,最大埋深H=12D,最大锚盘间距S=6D的18个螺旋锚上拔过程.分析锚盘埋深及间隔对上拔承载力及破坏模式的影响,并与已有理论公式进行对比.研究表明:很松状态的砂中,对于单锚盘螺旋锚,当埋深比H/D≤4时,破坏面以倒锥台形开展至地表,滑裂面倾角为5°~10°,将该倾角代入已有理论公式获得的上拔承载力与数值结果接近;当埋深比H/D>6时,破坏面局限在地表以下,形似气泡状.对于双锚盘螺旋锚,当锚盘间距比S/D=6时,发生独立破坏模式;当锚盘间距比S/D<4时,盘间土体破坏面为整体柱状,锚盘发挥效率较小,上拔承载力降低,因此建议螺旋锚间隔比S/D至少为4.In this paper,based on the ABAQUS finite element software,the Coupling Euler Lagrange method to deal with the problem of large deformation is adopted in loose sand to simulate the uplift process of 18 helical anchors which the plate diameter(D) is 0.4 m,the max embedment depth(H) is 12D,and the max spacing(S) between the plates is 6D.The influences of the embedment depth and the spacing of helcial plates on the uplift bearing capacity and failure mode are analyzed,also compared with the existing theoretical formulas.It shows that in the very loose sand,for the single helical anchor,when the relative embedment ratio H/D<4,the failure surface is a truncated cone developed to the surface.The inclination angle of the truncated cone is 5°~10°.The simulation values are close to the estimated values of the existing theoretical formulas which replace the inclination angle.When the relative embedment ratio H/D>6,a bubble failure surface is formed under the ground.For the double helical anchor,when the spacing ratio S/D=6,the efficiency of helical anchors is more than 90%,and the independent failure mode occurs.When the spacing ratio S/D<4,the efficiency of the helical anchor and the uplift bearing capacity are decrease,and the global failure mode occurs.Therefore,it is recommended that the spacing ratio S/D should be greater than 4.

关 键 词：螺旋锚基础 上拔承载力 破坏模式 耦合欧拉拉格朗日(CEL)法 

分 类 号：TU432[建筑科学—岩土工程]