Effects of embedment depth on the pullout capacity of bucket foundations in sand

2021 ◽  
Vol 237 ◽  
pp. 109643
Author(s):  
Vicent Ssenyondo ◽  
Seongho Hong ◽  
Taeho Bong ◽  
Sung-Ryul Kim
Keyword(s):  
Embedment Depth ◽  
Pullout Capacity

Horizontal Capacity of Embedded Suction Anchors in Clay

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
S. Bang ◽  
K. Jones ◽  
Y. S. Kim ◽  
Y. Cho
Keyword(s):  
Analytical Solution ◽  
Model Test ◽  
Soil Type ◽  
Embedment Depth ◽  
Centrifuge Model Test ◽  
Test Results ◽  
Pullout Capacity ◽  
Direct Function ◽  
Centrifuge Model ◽  
Factors Influencing

The embedded suction anchor (ESA) is a type of permanent offshore foundation that is installed by a suction pile. The primary factors influencing the horizontal pullout capacity of an ESA include the loading point, the soil type, the embedment depth, and the addition of flanges. The main purpose of this study is to develop an analytical solution that is capable of estimating the horizontal pullout capacity of ESAs with the loading point being anywhere along its length with or without flanges. An analytical solution has been developed to estimate the horizontal pullout capacity of embedded suction anchors in clay seafloor. Validation has been made through comparisons with the centrifuge model test results. Results indicate that the horizontal pullout capacity of the embedded suction anchor in clay increases, reaches its peak, and then starts to decrease as the point of the load application moves downward. The effect of flanges on the horizontal pullout capacity is also found to be significant. The horizontal pullout capacity is a direct function of the loading point. The horizontal pullout capacity increases as the loading point moves downward and the maximum pullout capacity is obtained when the loading point is approximately at the mid-depth. The increase in horizontal pullout capacity can be significant, i.e., more than twice in magnitude when the maximum pullout capacity is compared with that associated with the loading point near the top or tip.

scholarly journals Pullout Capacity Of Cylindrical Block Embedded In Sand

2018 ◽  
Vol 40 (1) ◽  
pp. 30-37
Author(s):  
Krzysztof Sternik ◽  
Katarzyna Dołżyk-Szypcio
Keyword(s):  
3D Model ◽  
Fe Analysis ◽  
Contact Friction ◽  
Embedment Depth ◽  
Pullout Capacity ◽  
Pullout Resistance ◽  
Pulling Forces ◽  
Pulling Force ◽  
Alternative Solutions ◽  
Cylindrical Block

Abstract Calculation of pullout capacity of anchoring concrete cylindrical block by finite element method is carried out. 3D model of the block assumes its free rotation. Alternative solutions with one and two pulling forces attached at different heights of the block are considered. Dependency of the ultimate pulling force on the points of its application, the block’s embedment depth as well as contact friction are investigated. Results of FE analysis and simple engineering estimations are compared. The maximum pullout resistance results from FE analysis when the rotation of the block is prevented.

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.

Numerical Investigation Into the Keying Process of a Plate Anchor Vertically Installed in Cohesionless Soil

2018 ◽  
Author(s):  
Nabil Al Hakeem ◽  
Charles Aubeny
Keyword(s):  
Peak Load ◽  
Offshore Structures ◽  
Cohesionless Soil ◽  
Soil Conditions ◽  
Embedment Depth ◽  
Pullout Capacity ◽  
Vertical Loading ◽  
Wide Range ◽  
Plate Anchor ◽  
Plate Anchors

Vertically driven plate anchors offer an attractive anchoring solution for floating offshore structures, as they are both highly efficient and suitable for a wide range of soil conditions. Since they are oriented vertically after installation, keying is required to orient the anchor into the direction of applied loading. Simulation of the keying process has not been extensively investigated by previous research, especially for cohesionless soil. Reliable prediction of irrecoverable embedment loss during keying is needed, since such loss can lead to significant reduction in the uplift capacity of the plate anchors. Large deformation finite element analyses LDFE method using RITSS (Remeshing and Interpolation Technique with Small Strain) were used to simulate the keying process of strip plate anchor embedded in uniform cohesionless soil. LDFE showed that the loss in embedment depth of plate anchor during rotation is inversely proportional to the loading eccentricity e/B. It was also found that the maximum pullout capacity occurs before the end of keying process at orientations between 60° to 85° degrees for vertical loading. Also, the LDFE study showed that reduced elastic soil stiffness leading to increased levels of displacement at which the peak load is approached.

scholarly journals Experimental Study of an Inflatable Recyclable Anchor

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Taoli Xiao ◽  
Yunlong He
Keyword(s):  
Bearing Capacity ◽  
Embedment Depth ◽  
The Novel ◽  
Low Carbon ◽  
Pullout Capacity ◽  
Force Transmission ◽  
Inflation Pressure ◽  
Foundation Pit ◽  
Anchor System ◽  
Repeated Use

This paper describes an investigation into the performance and pullout capacity of a new inflatable anchor system embedded in deep excavation engineering. The proposed inflatable recyclable anchor system consists of a rubber pneumatic bag, movable steel plate, and force transmission bar, which can all be recycled after use. By conducting a number of field pullout tests, it is found that the pullout bearing capacity of the proposed anchor is related to the inflation pressure, the length of the rubber pneumatic bag, and the embedment depth. It is found that, with the exponential increase of inflation pressure or length of the rubber pneumatic bag, the pullout bearing capacity of the novel inflatable anchor increases exponentially. The proposed inflatable recyclable anchor can meet the bearing requirements of traditional grouted anchors. Moreover, the proposed anchor not only has better supporting effects than traditional grouted ones, but it also has the advantages of recyclability, repeated use, and rapid formation of anchorage force. It is a new green and low-carbon anchorage, so it will have good application prospects in temporary foundation pit slope engineering.

scholarly journals Numerical and Experimental Investigation on Concrete Splitting Failure of Anchor Channels

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 502-522
Author(s):  
Anton Bogdanić ◽  
Daniele Casucci ◽  
Joško Ožbolt
Keyword(s):  
Construction Industry ◽  
Failure Mode ◽  
Current Trend ◽  
The United States ◽  
Embedment Depth ◽  
Test Results ◽  
Concrete Members ◽  
Splitting Failure ◽  
Edge Distance ◽  
Numerical Parametric Study

Concrete splitting failure due to tension load can occur when fastening systems are located close to an edge or corner of a concrete member, especially in thin members. This failure mode has not been extensively investigated for anchor channels. Given the current trend in the construction industry towards more slender concrete members, this failure mode will become more and more relevant. In addition, significantly different design rules in the United States and Europe indicate the need for harmonization between codes. Therefore, an extensive numerical parametric study was carried out to evaluate the influence of member thickness, edge distance, and anchor spacing on the capacity of anchor channels in uncracked and unreinforced concrete members. One of the main findings was that the characteristic edge distance depends on the member thickness and can be larger than 3hef (hef = embedment depth) for thin members. Based on the numerical and experimental test results, modifications of the design recommendations for the splitting failure mode are proposed. Overall, the authors recommend performing the splitting verification separately from the concrete breakout to design anchor channels in thin members more accurately.

scholarly journals Behavior of Offshore Pile in Calcareous Sand—Case Study

2021 ◽  
Vol 9 (8) ◽  
pp. 839
Author(s):  
Tarek N. Salem ◽  
Nadia M. Elkhawas ◽  
Ahmed M. Elnady
Keyword(s):  
Load Capacity ◽  
High Stress ◽  
Embedment Depth ◽  
Shear Stresses ◽  
Northern Coast ◽  
Compression Tests ◽  
Calcareous Sand ◽  
Element Analysis ◽  
Mixing Ratios

The erosion of limestone and calcarenite ridges that existed parallel to the Mediterranean shoreline forms the calcareous sand (CS) formation at the surface layer of Egypt's northern coast. The CS is often combined with broken shells which are considered geotechnically problematic due to their possible crushability and relatively high compressibility. In this research, CS samples collected from a site along the northern coast of Egypt are studied to better understand its behavior under normal and shear stresses. Reconstituted CS specimens with different ratios of broken shells (BS) are also investigated to study the effect of BS ratios on the soil mixture strength behavior. The strength is evaluated using laboratory direct-shear and one-dimensional compression tests (oedometer test). The CS specimens are not exposed to significant crushability even under relatively high-stress levels. In addition, a 3D finite element analysis (FEA) is presented in this paper to study the degradation offshore pile capacity in CS having different percentages of BS. The stress–strain results using oedometer tests are compared with a numerical model, and it gave identical matching for most cases. The effects of pile diameter and embedment depth parameters are then studied for the case study on the northern coast. Three different mixing ratios of CS and BS have been used, CS + 10% BS, CS + 30% BS, and CS + 50% BS, which resulted in a decrease of the ultimate vertical compression pile load capacity by 8.8%, 15%, and 16%, respectively.

scholarly journals Design of plate and screw anchors in dense sand: failure mechanism, capacity and deformation

2019 ◽  
Vol 92 ◽  
pp. 16010
Author(s):  
Benjamin Cerfontaine ◽  
Jonathan Knappett ◽  
Michael Brown ◽  
Aaron Bradshaw
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Failure Mechanism ◽  
Progressive Failure ◽  
Vertical Direction ◽  
Shear Plane ◽  
Design Methods ◽  
Embedment Depth ◽  
Limiting State ◽  
Dense Sand

Plate and screw anchors provide a significant uplift capacity and have multiple applications in both onshore and offshore geotechnical engineering. Uplift design methods are mostly based on semi-empirical approaches assuming a failure mechanism, a normal and a shear stress distribution at failure and empirical factors back-calculated against experimental data. However, these design methods are shown to under- or overpredict most of the existing larger scale experimental tests. Numerical FE simulations are undertaken to provide new insight into the failure mechanism and stress distribution which should be considered in anchor design in dense sand. Results show that a conical shallow wedge whose inclination to the vertical direction is equal to the dilation angle is a good approximation of the failure mechanism in sand. This shallow mechanism has been observed in each case for relative embedment ratios (depth/diameter) ranging from 1 to 9. However, the stress distribution varies non-linearly with depth, due to the soil deformability and progressive failure. A sharp peak of normal and shear stress can be identified close to the anchor edge, before a gradual decrease with increasing distance along the shear plane. The peak stress magnitude increases almost linearly with embedment depth at larger relative embedment ratios. Although further research is necessary, these results lay the basis for the development of a new generation of design criteria for determining anchor capacity at the ultimate limiting state.

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