The ultimate pullout capacity of anchors in frictional soils

2006 ◽  
Vol 43 (8) ◽  
pp. 852-868 ◽  
Author(s):  
R S Merifield ◽  
S W Sloan
Keyword(s):  
Finite Element ◽  
Lower Bound ◽  
Limit Analysis ◽  
Numerical Study ◽  
Past Research ◽  
Pullout Capacity ◽  
Current Design ◽  
Pullout Load ◽  
Ultimate Pullout Capacity ◽  
Frictional Soils

During the last 30 years various researchers have proposed approximate techniques to estimate the uplift capacity of soil anchors. As the majority of past research has been experimentally based, much current design practice is based on empiricism. Somewhat surprisingly, very few numerical analyses have been performed to determine the ultimate pullout loads of anchors. This paper presents the results of a rigorous numerical study to estimate the ultimate pullout load for vertical and horizontal plate anchors in frictional soils. Rigorous bounds have been obtained using two numerical procedures that are based on finite element formulations of the upper and lower bound theorems of limit analysis. For comparison purposes, numerical estimates of the break-out factor have also been obtained using the more conventional displacement finite element method. Results are presented in the familiar form of break-out factors based on various soil strength profiles and geometries and are compared with existing numerical and empirical solutions.Key words: anchor, pullout capacity, finite elements, limit analysis, lower bound, sand.

Finite element limit analysis of pullout capacity of planar caissons in clay

2016 ◽  
Vol 75 ◽  
pp. 12-17 ◽  
Author(s):  
Suraparb Keawsawasvong ◽  
Boonchai Ukritchon
Keyword(s):  
Finite Element ◽  
Limit Analysis ◽  
Pullout Capacity

scholarly journals Ultimate Pullout Capacity of a Square Plate Anchor in Clay with an Interbedded Stiff Layer

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Tugen Feng ◽  
Jingyao Zong ◽  
Wei Jiang ◽  
Jian Zhang ◽  
Jian Song
Keyword(s):  
Finite Element ◽  
Empirical Formula ◽  
Soil Layer ◽  
Embedment Depth ◽  
Layered Soils ◽  
Pullout Capacity ◽  
Plate Anchor ◽  
Square Plate ◽  
Plate Anchors ◽  
Ultimate Pullout Capacity

Three-dimensional nonlinear numerical analysis is carried out to determine the ultimate pullout capacity of a square plate anchor in layered clay using the large finite element analysis software ABAQUS. An empirical formula for the pullout bearing capacity coefficient of a plate anchor in layered soils is proposed based on the bearing characteristics of plate anchors in single-layer soils. The results show that a circular flow (circulation field) is induced around the plate anchor during the uplift process and that the flow velocity and circulation field range are mainly affected by the properties of the soil around the plate anchor. The bearing characteristics of plate anchors in layered soils are influenced by factors such as the embedment depth of the plate anchor, the friction coefficient between the soil and the plate anchor, the thickness of the upper soil layer, and the thickness of the middle soil layer. The rationality of the finite element numerical calculation results and the empirical formula is verified by comparing the results from this study with results previously reported in the literature.

A note on vertical cuts in homogeneous soils

1993 ◽  
Vol 30 (5) ◽  
pp. 859-862 ◽  
Author(s):  
D.N. Singh ◽  
P.K. Basudhar
Keyword(s):  
Finite Element ◽  
Nonlinear Programming ◽  
Lower Bound ◽  
Limit Load ◽  
Cohesive Soils ◽  
Stability Number ◽  
Discrete Elements ◽  
Programming Technique ◽  
The Stability ◽  
Frictional Soils

In this note, the modified Lysmer method based on discrete elements and nonlinear programming technique has been extended to study the stability of a vertical cut in both homogeneous cohesive and cohesive–frictional soils to obtain lower bound solutions. For saturated clays under undrained condition, the calculated stability number (3.69) is closer to the upper bound value (3.78) than the lower bound value (3.64) reported in the literature until now. For cohesive–frictional soils, the obtained lower bound limit load compares well with that using a finite-element elastoplastic solution. Key words : lower bound, vertical cut, cohesive soils, stability number, discrete element, nonlinear programming.

Effect of anchor width on pullout capacity of strip anchors in sand

2011 ◽  
Vol 48 (3) ◽  
pp. 511-517 ◽  
Author(s):  
Vishwas N. Khatri ◽  
Jyant Kumar
Keyword(s):  
Finite Element ◽  
Linear Programming ◽  
Lower Bound ◽  
Granular Medium ◽  
Iterative Procedure ◽  
Friction Angle ◽  
Pullout Capacity ◽  
Anchor Plate ◽  
Uplift Pressure ◽  
Uplift Resistance

By incorporating the variation of peak soil friction angle ([Formula: see text]) with mean principal stress (σm), the effect of anchor width (B) on vertical uplift resistance of a strip anchor plate has been examined. The anchor was embedded horizontally in a granular medium. The analysis was performed using lower bound finite element limit analysis and linear programming. An iterative procedure, proposed recently by the authors, was implemented to incorporate the variation of [Formula: see text] with σm. It is noted that for a given embedment ratio, with a decrease in anchor width (B), (i) the uplift factor (Fγ) increases continuously and (ii) the average ultimate uplift pressure (qu) decreases quite significantly. The scale effect becomes more pronounced at greater embedment ratios.

scholarly journals Numerical Study on the Effect of Concrete Grade on the CFT Circular Column’s Behavior under Axial Load

2019 ◽  
Vol 5 (11) ◽  
pp. 2359-2376
Author(s):  
Baitollah Badarloo ◽  
Faezeh Jafari
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Design Method ◽  
Load Capacity ◽  
Pushover Analysis ◽  
Safety Level ◽  
Finite Element Software ◽  
Current Design ◽  
Load Pattern ◽  
Cft Column

Concrete-filled tubular (CFT) column improves the structure properties under different load pattern, so that it should be designed under two main load patterns (static and cyclic load) using current design method such as Finite Element Method (FEM) and analytical method (guideline equation). In this research, a CFT column with specific dimensions is modeled by using ABAQUS finite element software; the target of this study is to conduct a pushover analysis and also a hysteresis analysis under cyclic loading. Then, the concrete grade and percentage of column reinforcement were altered using the FEM, and eventually, compared with the results of analytical equations to measure the safety level of analytical equations. For this purpose, the CFT columns with C20, 30, 40 & 50 concrete cores were modeled with and without reinforcement, and the effect of concrete grade on the capacity of column was studied. In addition, MATLAB software was used to obtain beta index and load capacity design for the CFT column. The results demonstrated that the columns designed in accordance with the AISC have a good performance under the cyclic and static loading. The safety level of design equations ranged between 3 and 5, and the columns could resist higher loads (about 2.5-3.5 times) through the design by ABAQUS.

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