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Advancements in industry and increased energy demands have led to the construction of onshore and offshore platforms. The stability of these platforms is a major challenge for geotechnical engineers. Expandable anchors have recently been proposed to address this issue. Researchers have investigated the bearing capacity of anchors with different shapes and plate numbers using experimental and numerical methods. The use of a suitable method for numerical modeling of expandable anchors is necessary to determine their performance. The current study evaluated the bearing capacity of multi-plate anchors using the coupled Eulerian-Lagrangian, discrete element, and finite element methods and compares their results. The effect of an increase in the number of plates (to three), the distance between plates, the plate shape (square or circular), and the soil density (80% or 60%) on the bearing capacity of the anchors was determined. The results showed that the Eulerian model was in very good agreement with the experimental results and that the square anchor exhibited a higher bearing capacity than the circular anchor. An equation is proposed for the calculation of the bearing capacity of expandable anchors. [ABSTRACT FROM AUTHOR]

The critical penetration depth and failure displacement of vertically loaded anchor (VLA) have already been investigated. However, only few investigations focused on the double-plate VLA. Therefore, based on the finite element method, the critical penetration depth for the double-plate VLA was obtained, which is approximately 6.0 times the width of the upper fluke of the double-plate VLA. According to the reduced-scale model tests, the failure displacement of the double-plate VLA with different included angles and dimensions of the bottom fluke under shallow-embedded and deep-embedded conditions was obtained. Furthermore, the failure displacement of double-plate VLA with 30° included angle and the dimension of bottom fluke equal to that of upper fluke under shallow-embedded and deep-embedded condition is 0.29 and 0.67 times the width of upper fluke, respectively. Based on the empirical bearing capacity formula for VLA model, an improved bearing capacity formula for double-plate VLA model has been put forward; by means of the improved bearing capacity formula, the coefficient of bearing capacity for double-plate VLA under shallow-embedded and deep-embedded condition is obtained to be 5.013 and 4.106, respectively. [ABSTRACT FROM AUTHOR]

Although fiber reinforced polymers (FRPs) have become the most widely used material to strengthened existing concrete structures in shear, premature debonding of externally bonded FRP remains a significant cause of material under-utilisation. In an effort to suppress debonding failure, research has shown that the use of ±45° bidirectional fabric patch anchors can delay the occurrence of FRP debonding. However, most research to date on patch anchors has been based on joint-level tests and the data available on full-scale beam applications has been very limited. One means by which additional data can be generated on the performance of patch anchors when applied to full-scale beams is using finite element simulations. This paper presents a 2D and 3D non-linear finite element model calibrated using available data on prestressed T-beams strengthened in shear with FRP laminates and patch anchors. The models captured the failure modes, strains in the FRP and crack patterns of the specimens very well and predicted the failure load for the control, strengthened and anchored specimens within a margin of difference of 6–9%, 4–13% and 1–2%, respectively. Parametric studies involving variation of concrete strength and FRP thickness were conducted to generate additional data and the research findings are presented. [ABSTRACT FROM AUTHOR]

This paper presents numerical solutions for determining the uplift capacity of strip plate anchors embedded at different positions either from the toe or crest of cohesive-frictional soil slope. Finite element method based on lower bound theorem of limit analysis in combination with second-order cone programming has been used for obtaining the solutions. Dimensionless uplift factors are used for estimating the ultimate uplift resistance of anchors due to contribution of cohesion, unit weight and angle of internal friction of soil. For different edge-distance of anchor either from the crest or toe of the slope, computations are carried out for different combinations of internal friction angle of soil, angle and height of sloping surface, normalised strength of soil, and embedment ratio of anchors. The uplift capacity has been found to remain the same within a zone extending from the middle of the slope towards both toe and crest of sloping ground. [ABSTRACT FROM AUTHOR]

Soil anchors are among the most widely used reinforcements to stabilize unstable soil mass or stabilize and anchor structures built in onshore and offshore regions. Anchors are generally installed in soil and rocky environments by penetration and embedment methods. These methods are classified into two main groups of grouted and mechanical anchors. In the present study, Expandable Mechanical Plate Anchors (EMPLAs), a new generation of mechanical anchors, are introduced and their bearing capacities are evaluated. EMPLAs can be implemented, locked, and activated in the soil more cheaply and with a lower driving force. Previous studies have validated the efficiency of these anchorages based on the experimental test results. Here, it is tried to evaluate the effect of properties of anchor plates such as their shape and curvature on the locking mechanism, as well as the ultimate bearing capacity of reinforcement and drop rate of locking force under a constant pullout speed rate. Furthermore, the ultimate bearing capacity of the anchors is calculated using two methods of 1) the well-known theories for calculating the tensile bearing capacity of plate anchors in cohesionless soil and 2) numerical modeling using finite element software. The results from both methods showed that the plate curvature intensity had a great impact on the plates opening rate and, consequently, faster locking and activation of the reinforcement at the higher embedment depth. Eventually, the effective zone of the soil at the top of the expandable plates during a 90° rotation of the plates and lockage of the reinforcement was monitored using the Particle Image Velocimetry (PIV) technique. [ABSTRACT FROM AUTHOR]

This paper presents an improved plasticity force-resultant model for anchors deeply embedded in clays, developed from large deformation finite element analyses. The current available force-resultant models for anchors are mainly developed from small strain finite element analysis while experimental approach has not been used due to technical challenges. The advantage of large deformation finite element analysis is that it provides much more data points to fit the yield surface than small strain finite element analysis, in addition to avoiding excess mesh distortion problems. Furthermore, the flow rule or normality can be effectively checked in the large deformation finite element analysis and further used to improve the fitting quality. After validated against retrospective simulations, the better performance of the developed plasticity force-resultant model is demonstrated by comparing with available experimental observations from centrifuge test. [ABSTRACT FROM AUTHOR]

Numerical solutions have been obtained for the vertical uplift capacity of strip plate anchors embedded adjacent to sloping ground in fully cohesive soil under undrained condition. The analysis was performed using finite element lower bound limit analysis with second-order conic optimization technique. The effect of anchor edge distance from the crest of slope, angle and height of slope, normalized overburden pressure due to soil self-weight, and embedded depth of anchor on the uplift capacity has been examined. A nondimensional uplift factor defined as Fcγ owing to the combined contribution of soil cohesion (cu), and soil unit weight (γ) is used for expressing the uplift capacity. For an anchor buried near to a sloping ground, the ultimate uplift capacity is dependent on either pullout failure of anchor or overall slope failure. The magnitude of Fcγ has been found to increase with an increase in the normalized overburden pressure up to a certain maximum value, beyond which either the behavior of anchor transfers from shallow to deep anchor or overall slope failure occurs. [ABSTRACT FROM AUTHOR]

Current floating structures require more reliable and higher anchoring capacities because of their increased size. A suction anchor is one of the most popular anchors for a floating system. In this study, the behavior of a suction anchor installed in cohesionless soil was investigated when the anchor was subjected to mainly a horizontal load. Three-dimensional finite element numerical analyses were carried out using ABAQUS, and three centrifuge tests were performed to calibrate the numerical analyses. A parametric study with different dimensions and loading points for the suction anchor was conducted. The horizontal capacity of the suction anchor was estimated, and the soil reaction distribution was analyzed when the load was applied at the optimal point. Based on the results, an analytical equation for calculating the horizontal capacity of a suction anchor was proposed that can be easily adopted for design. [ABSTRACT FROM PUBLISHER]

Objective: Develop a finite element (FE) model of a skull to perform biomechanical studies of maxillary expansion using bone anchors (BA). Materials and methods: A skull model was developed and assigned material properties based on Hounsfield unit (HU) values of cone-beam computerized tomography (CBCT) images. A 3 mm diameter cylindrical BA was modelled and inserted in the palatal bone. A 4 mm transverse displacement was applied on the anchor. An evaluation on the effect on local stresses of BA implantation inclination angle was performed. Results: Proper displacement results and strain-stress trends for the expansion process were present. Stress distribution patterns were similar as reported in the literature. No significant difference between BA inclination angles was found. Conclusion: This work leads to a better understanding and prediction of craniofacial and maxillary bone remodelling during ME with BA treatments and is a first step towards the development of patient specific treatments. [ABSTRACT FROM AUTHOR]