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The conventional Mohr–Coulomb (M-C) failure criterion is commonly used in existing studies to determine the ultimate pullout capacity of plate anchors buried in cohesive-frictional soils. However, this criterion overestimates the tensile strength of these soils by assuming a linear failure envelope (in both compression and tensile regimes) within the normal-shear stress space. In this study, the ultimate pullout capacity of horizontally buried plate anchors in cohesive-frictional soils was determined, accounting for the effect of tensile strength cutoff. The study proposed a series of semianalytical solutions utilizing the kinematic horizontal slice approach and investigated the ultimate pullout capacity of four different anchor shapes, including circular, square, rectangular, and strip anchors. The impact of nonassociated flow rule on the results was also examined. It has been observed that the results obtained using the M-C failure criterion with a tension cutoff are significantly lower than those obtained using the conventional M-C failure criterion. The difference between both results increases as soil cohesive strength increases and anchor burial depth decreases. These findings clearly demonstrate that eliminating tensile strength from the strength envelope leads to a more conservative estimate of plate anchor pullout capacity. The study emphasizes changes in anchor failure surfaces for various parameter combinations and provides results that are consistent with specific solutions reported in the literature. Practical Applications: The study investigates using plate anchors to enhance the stability of both onshore and offshore structures, including transmission towers, guyed masts, chimneys, and mooring platforms. These structures often encounter significant vertical pullout forces. The research establishes a theoretical framework for calculating the ultimate vertical pullout capacity of plate anchors with various shapes (strip, rectangular, and circular) when buried in cohesive-frictional soils. A crucial aspect of this analysis involves incorporating the specified/limited value of tensile strength in cohesive-frictional soils when assessing the ultimate pullout capacity of plate anchors. This consideration is vital for ensuring a safe and conservative design, especially for structures subject to uplift forces. The findings provide valuable insights for engineers and practitioners, offering a reliable method to optimize the usage of plate anchors in the design of pullout-resistant structures. [ABSTRACT FROM AUTHOR]

The existing research on anchor foundations has predominantly focused on their axial load-carrying capacity, disregarding their resistance to the combined uplift and lateral forces during operation. To address this gap, the present study employs a three-dimensional finite-difference analysis to examine the behavior of horizontal anchor foundations buried in sand under the influence of uplift and lateral loads. The novelty of this work lies in the application of combined loading on the shaft head and the subsequent evaluation of both vertical and horizontal displacements of the foundation. The results reveal that the displacements are notably more significant in the horizontal direction. Furthermore, the paper presents a detailed analysis of the foundation's failure mechanisms under various combinations of vertical and horizontal forces. It is observed that pure vertical forces induce an uplift shear failure, whereas pure horizontal forces lead to a rotational failure. Based on the results, a failure envelope in the V:H loading plane is proposed for the horizontal anchor foundation subjected to oblique loads. [ABSTRACT FROM AUTHOR]

Plate anchors have great advantages that are useful in deep or ultradeep water mooring systems. The keying behaviors have a deep effect on the embedment loss and pullout capacity of strip plate anchors. In this paper, the effect of soil remolding on the keying behaviors of strip plate anchors is studied by large deformation finite-element (LDFE) analysis. First, the LDFE results are compared with centrifugal test results, theoretical solutions, and LDFE data from previous literature, showing good agreement. Then, a series of LDFE cases is studied to investigate the effects of the padeye offset, load eccentricity, soil sensitivity, and initial embedment depth on the embedment loss and pullout capacity of plate anchors during the keying process. The LDFE results show that different load eccentricity corresponds to different soil failure mechanisms, and both padeye offset and soil remolding will reduce the pullout capacity of plate anchors. Finally, an equivalent soil strength is introduced considering rate effect and soil remolding of clay. A combined factor and an equivalent ultimate pullout capacity are used to estimate the ultimate embedment loss and pullout capacity of strip plate anchors in uniform clay, respectively. [ABSTRACT FROM AUTHOR]

Prestress loss of anchor cables can cause a change in the internal force for the support structure of a foundation pit or slope, which may cause engineering accidents. The coupling effect between an anchor cable and the creep of rock and soil is the main factor that leads to the loss of prestress of the anchor cables. However, the traditional Hooke–Kelvin (H-K) viscoelastic model could not accurately predict the long-term loss of prestress. To solve this problem, based on the H-K viscoelastic model, a new H-3K viscoelastic model was proposed, consisting of two generalized Kelvin bodies connected in parallel, and its creep equation and relaxation equation were also derived. Focusing on slope engineering in Longnan City, Gansu Province, China, the prestress of anchor cables calculated by the proposed model were compared with the monitoring data. The result that the H-K creep coupling model is more accurate in predicting prestress loss of anchor cables in the initial stage, but from a long-term perspective, the H-3K creep coupling model provided a more accurate prediction. By connecting more generalized Kelvin bodies in parallel, stress shared by the elastic body can be reduced and stress loss due to anchor cable relaxation can be approximately compensated for to make the prediction results closer to the monitored values. However, when there are more than three Kelvin bodies in parallel, the model prediction results will change only slightly. Therefore, the H-3K creep coupling model is sufficient for practical engineering. [ABSTRACT FROM AUTHOR]

An important research topic in reinforcing deep soft soil slopes is the pullout distribution of a long anchor with multiple grout bulbs under various factors. The nonlinear variation between the compaction effect and grout bulb diameter was first quantitatively described using an exponential model. The pullout force of a long anchor with multiple grout bulbs was then calculated using a modified model considering the compaction effect. After verification based on the model test data, a parametric analysis was carried out on the elastic modulus of the anchor rod, grout bulb diameters, bulb numbers, and bulb sequences. The results indicated that a larger elastic modulus leads to a more obvious hardening behavior and a lower mobilized displacement of the pullout force. The grout bulb diameter significantly influences the ultimate pullout force and the mobilized displacement of the pullout force. Although the bulb number affects the ultimate pullout force and the distribution of the pullout force, the mobilized displacement of the pullout force does not change. For a long anchor with multiple grout bulbs, the sequence of the bulb diameters has a significant impact on the ultimate pullout force and the distribution and mobilized displacement of the pullout force. [ABSTRACT FROM AUTHOR]

Nowadays, plate anchors have many applications in onshore and offshore projects. These plates can be used vertically or horizontally in their application. For the stabilization of retaining walls, vertical plate anchors are used, and some research on the performance of single plate anchors has been carried out. However, few studies have considered the effect of using multiplate anchors for mechanically stabilized earth walls, and therefore more research is required in this area. In the present study, the effects of the number of plate anchors, the inclination angle of plate anchors, the distances between plate anchors, and the change in the ratio of loading heel distance (d) to wall height (H) under constant strain loading was determined experimentally. To capture the type and location of the critical slip surface occurring in the wall and the effects of variables on the shape of a failure wedge, the particle image velocimetry (PIV) method was used. According to the results, the triple plate anchors indicated the lowest horizontal displacement and the highest bearing capacity compared with single and double plate anchors. By increasing the inclination angle of the plate anchors from 0° to 60°, the horizontal displacement increased, and alternatively, the bearing capacity decreased. By reducing the ratio of d/H from 0.4 to 0.2, the horizontal displacement of the wall increased and the bearing capacity decreased. Moreover, the PIV results showed that by increasing the inclination angle of the plate anchors, reducing the distance between the plates, and decreasing the ratio of d/H, the width of the critical slip surface and movement of soil particles increased. [ABSTRACT FROM AUTHOR]

Despite the widespread usage of the anchoring technique in geotechnical projects in Brazil, mainly in underground works and retaining walls, limited research has been carried out on the determination of load capacity in anchors. Ground anchored walls in Brazil are often dimensioned by methodologies that are not satisfactorily adapted to the reality of the national soil. In this context, this work proposes a simplified computational methodology for forecasting the load capacity of anchors in geotechnical projects. To this end, a fuzzy model is proposed using specific selected characteristics of the soils and geometry of tieback wall systems, whose measurements are easier to be obtained when compared with the load capacity measurement itself. For validation, calibration, and application of the model, the results of 40 performance tests (load tests) were used. Thirty-two samples were used to train the algorithm whereas eight were used to test the model. The results obtained using the proposed approach were close to the extrapolated values of the performance tests according to the existing empirical method, showing that the model is a viable alternative for the design of anchors. Finally, the methodology presented in this work seems to be a first step for the prediction of the anchor bearing capacity and therefore it will certainly benefit from the addition of new test databases of different locations around the world. [ABSTRACT FROM AUTHOR]

The frame beam anchor plate (FBAP) is a new supporting structure to reinforce backfill. The current studies of slope stability concentrate on homogeneous isotropic dry or saturated slopes according to two-dimensional assumptions. In engineering practice, however, the soils are heterogeneous and anisotropic and exhibit evident unsaturated characteristics, and the failure surface shows obvious three-dimensional (3D) characteristics universally. A new method for evaluating the 3D stability of unsaturated soil slopes reinforced with FBAPs is established in this paper. The upper-bound analytical solution of slope safety factor (Fs) is derived based on the energy balance equation incorporated with the 3D spiral failure mechanism and the gravity increase method (GIM). Comparisons verified the effectiveness of the methodology and the optimization program. The influence of unsaturated characteristics, support structure design parameters, and seismic force on the 3D slope stability is evaluated through parameter analysis. The results show that the shear strength prediction model is crucial in slope stability assessments. The stability of slopes can be significantly improved by about 29%–52% by using FBAPs. Seismic action has a significant negative impact on the slope stability. When kh increases from 0 to 0.3, Fs generally decreases by about 40%–55%. [ABSTRACT FROM AUTHOR]

An h-type prestressed anchor cable antislide pile is suggested for dealing with large-scale landslide disasters. At present, the internal force calculation of h-type antislide piles includes a great deal of cumbersome and complex calculus and graph multiplication processes, and the research on the action mechanism of prestressed anchor cables is insufficient. To simplify the calculation process, this study proposes an improved calculation method for the internal force and displacement of the h-type prestressed anchor cable antislide pile. A method to simplify the h-type antislide pile into a plane rigid frame calculation model is proposed, and the action of the anchor cable is added to the pile structure in the form of an unchanged tension. Then, the pile is divided into a loaded section and an anchorage section with the sliding surface as the boundary. Based on the engineering case, the results of internal force and displacement obtained through an improved calculation method, numerical simulation method, and graph multiplication method are compared and analyzed to verify the accuracy and applicability of the improved method. Finally, based on the improved calculation method, the internal force and displacement characteristics of piles are analyzed and compared under different support modes, including h-type pile, h-type with single-row anchor cable, and h-type with double-row anchor cables, and the support characteristics of the h-type prestressed anchor cable antislide pile are investigated. The results show that the tension of the anchor cable can effectively reduce the bending moment and displacement of piles. Compared with the h-type antislide pile, adding two prestressed anchor cables can reduce the maximum positive and negative bending moments of the front and rear piles by 14.8%, 14.5%, 9.4%, and 8.7%, respectively, and reduce the horizontal displacement of the top of the rear pile by 21.7%. [ABSTRACT FROM AUTHOR]

Helical anchors are receiving more attention these days due to their economic and environmental advantages. However, the behavior of these structures requires further investigation. One of the critical areas requiring further attention is their failure mechanism under monotonic loading conditions. This study presents the results of centrifuge testing of half-models of helical anchors behind a Perspex window, performed to visualize the failure mechanism of screw anchors using particle image velocimetry analysis. The density change that is a result of installation disturbance was simulated by a novel technique. The results showed that embedment depth had a great influence on the failure mechanism of the anchors. The critical embedment depth ratio determined was H/D = 4–5 that separated the shallow and deep behavior of the anchors. Soil was mobilized as a reverse truncated cone in the shallow mode, while a flow-around mechanism was formed in the deep mode. The inclination of the mobilized zone on both sides of the helix was close to the critical state friction angle (29°) in shallow mode. The inclination of the failure surface was related to the dilation angle of the sand in the deep mode. A minimum distance of 3D was recommended to minimize the interaction of adjacent helical plates in a multihelix anchor. In addition, a distance of 4D was suggested to minimize the interaction of adjacent helical anchors in a group. [ABSTRACT FROM AUTHOR]

The load-transfer mechanism of tensioned anchors is primarily concerned with in-service performance, which depends on the bond–slip behavior of anchoring interface. Because the interface bond–slip behavior is conventionally modeled using epistemic experience of specific researchers and/or back analysis of specific in situ testing results, it is challenging to develop a straightforward load-transfer analysis with extensive applicability. A generalized load-transfer modeling framework was implemented in this work by incorporating a versatile interface bond–slip model that can be derived from experimental characterization of respective types of element-anchoring interface. The adhesion and friction were modeled with interface slip to constitute the interface bond using rational and exponential functions, respectively. The pullout tests on element-scale and large-scale specimens of a typical anchor type (i.e., tensioned steel tube embedded in cemented soils) were carried out to calibrate the parameters of the interface model and to validate the predicting capability of the modeling framework, respectively. In addition, the versatility of this load-transfer modeling framework was examined for two other anchor types reported in the literature (i.e., tensioned rock anchor and tensioned GFRP anchor embedded in sands). The consistent good agreements between predictions and measurements of these anchor types verified the effectiveness and applicability of the generalized load-transfer modeling framework. Based on the load-transfer analysis for the tensioned steel tube in model testing, a parametric study was performed to investigate the impact of axial stiffness and bond length on load-transfer responses of the tensioned anchor. [ABSTRACT FROM AUTHOR]

This paper presents an investigation into the influence of the size of nongrouted anchor nails on the role of anchorage capacity in a flexible protected system. A lateral pullout test was used to examine the deformation, pullout capacity, and failure mode of anchor nails with different lengths and diameters. There could be three failure modes, namely rotation failure, bending failure, and tension failure. The theoretical models were established for different failure modes, and a corresponding solution for critical pullout force was derived. Moreover, the applicability of the theoretical models was verified by the consistency between the measured value and calculated value, which seems to show that the models could predict the displacement and the resistance of anchor nails under lateral force. With a fixed diameter, an increase in the length of the anchor nail contributes to a longer bending length, but the ratio of bending length to total length is consistent with the variation of the ultimate pullout capacity—both of which increase first and then decrease. On the contrary, length unchanged, the bending length and the ratio of bending length to total length decrease with a larger diameter, while the ultimate pullout capacity increases. [ABSTRACT FROM AUTHOR]

Considering the nonlinearity and heterogeneity of geotechnical materials, the ultimate pullout capacity of a shallow horizontal strip anchor plate is determined based on the upper-bound limit analysis theory and the nonlinear Mohr–Coulomb failure criterion. The ultimate pullout capacity and the soil rupture surface, as well as its stress distribution, are obtained by Euler equations and the Runge–Kutta process. The effectiveness of the variation method is verified by comparisons with existing results and numerical results. Furthermore, the effects of variation coefficients of geotechnical parameters and buried depth on the ultimate pullout capacity are analyzed. Results indicate that (1) the ultimate pullout capacity increases with the variation coefficients of the shear strength parameters, and opposite parameters result in symmetrical failure patterns. (2) The normal stress on the rupture surface is only related to the unit weight and depth. The proposed variation method provides a reliable and rigorous upper-bound solution of the pullout capacity of strip anchor plates embedded in nonhomogeneous materials, and it would provide a useful reference for the engineering design of anchor plates. [ABSTRACT FROM AUTHOR]

Pressure-dispersed compression anchor consists of several anchor units fitted with an end plate. Limited field tests have been conducted to investigate the performance of a pressure-dispersed compression anchor system in cohesive soil. This paper conducted a series of field pullout loading test of pressure-dispersed compression anchors in clay soils, considering the following influence factors of stressing sequence, grouting method and compensation load. The simultaneous stressing yielded less pullout capacity than the individual stressing because of the relatively large interaction between the units. With the increase of the load level, the movement ratio decreased with a gradually decreased rate, followed by a slight increase when the load level exceeded 0.7. The rebound stiffness declined as the load level increased and the individual stressing yielded smaller reduction in the rebound stiffness than the simultaneous stressing. The back calculation indicated that the effective anchor diameter was enlarged by 10% due to the post grouting with a grouting factor of 0.2. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study on the pullout behavior of a vertical plate anchor buried in sand under lateral loading, using the digital image correlation (DIC) technique. Based on image analysis, the influences of anchor embedment ratio, sand relative density, and sand–plate interface friction on the failure and deformation mechanisms were discussed. With lateral displacements, the plate anchor experienced passive soil pressure in the front and active soil pressure from the behind. It is observed that the passive failure surfaces varied from approximately linear to be curved and finally became locally rotational with increasing embedment ratios, which indicated that the failure mode transitioned from general shear to be local shear gradually. The failure process is progressive in nature, and the critical embedment ratio is sand-state dependent. With an increasing relative density of sand, the front passive failure zone became larger, whereas the scope of the active failure zone reduced. A wider range of soil may be mobilized by plate anchors of a greater interface frictional strength, leading to enhanced anchor capacity, and this effect decreased with increasing anchor embedment ratios and vanished for deep anchors. The test findings can provide useful visualized data for the development and verification of relevant theoretical models. [ABSTRACT FROM AUTHOR]

Vertical plate anchors are being widely used in the construction of earth retaining structures. In the present study, experimental and numerical investigations were carried out to develop an understanding of the behavior of geocell-reinforced vertical plate anchors in sand. The parameters studied include anchor embedment depth, strength of geocell reinforcement, and geocell-soil interface friction angle. It was observed that geocell reinforcement can significantly enhance the anchor capacity, both at shallow and deeper embedment. The unreinforced anchor, at an embedment depth of about seven times its height, tended to reach a critical stage beyond which the loadcarrying capacity did not increase much. However, with geocell reinforcement, this limitation was overcome and the pullout capacity continued to increase further. Moreover, a shallow anchor with geocell reinforcement could perform better than the unreinforced anchor placed deeper. The central portion of the geocell mattress close to the anchor plate actively sustains the loading, and the end portions serve in a secondary manner to mobilize passive resistance from the surrounding soil. For better performance improvement, the geocell-soil stiffness ratio should be in the range of 5-30. With increases of the geocell-soil interface friction angle beyond 1.8 times the soil friction angle, further increases in performance improvement tend to be negligible. [ABSTRACT FROM AUTHOR]

Plate anchors are embedded into the ocean floor to provide holding capacity for offshore structures. Anchor holding capacity is a function of both the anchor and soil properties. Although plate anchors have been widely studied experimentally and numerically, there is still no universally agreed-upon design approach, indicating that the problem physics remain elusive. In this work, discrete-element method (DEM) simulations were used to investigate the behavior of plate anchors during pullout in an effort to elucidate some of the microscale physical processes that influence overall system behavior. Macroscale assembly response was compared to published experimental results and empirical solutions. The influence of embedment ratio, anchor roughness, soil density, and anchor size on holding capacity was investigated, and system-scale results reasonably agreed with previously published work. Thus, observations of the simulated contact force network and particle velocity during uplift were used to provide insight into anchor failure mechanisms. Finally, the model was used to briefly explore the response of a cyclically loaded plate anchor embedded in a granular assembly. [ABSTRACT FROM AUTHOR]

The estimation of the undrained pullout capacity of plate anchors is vital for the design of offshore floating facilities and has been an active topic of research for several years. Most of the previous studies have proposed empirical relationships to predict the undrained pullout capacities of inclined anchors. Generally, the buoyancy effect is added to the shearing resistance to obtain the total capacity, which is less than or equal to the maximum capacity. In this paper, an alternative mechanism-based simple design methodology is proposed to estimate the undrained pullout capacity of inclined anchors. A series of finite-element analyses are performed for a range of anchor inclinations in soils with uniform and heterogeneous shear strength. The effects of anchor embedment, soil unit weight, and anchor-soil interface tensile capacity are studied in a systematic manner. A relationship has been developed to estimate the depth at which the anchor undergoes a transition in the failure mechanism from shallow to deep failure mode. Robustness of the proposed methodology is also examined for a generalized shear strength profile of the soil. The proposed model estimates pullout capacity with the maximum error being less than 5% for any soil or anchor property. [ABSTRACT FROM AUTHOR]

An experimental study on the load-carrying mechanism of vertical plate anchors is presented and discussed. It was found that, with a shallow anchor, the rupture surface reached the ground surface, leading to a general shear failure, whereas with deeper embedment, the rupture surface was localized around the anchor. Anchors placed close to the ground surface failed in linear rupture but, when embedded within the failure mechanism, were very close to the polar curve of a logarithmic spiral, which, however, tends to be nearly circular for deeper depths of embedment. The size of rupture surface increases with an increase in density of fill soil that mobilizes higher resistance, leading to enhanced anchor capacity. The critical embedment depth beyond which the anchor breakout factor does not change much is found to be approximately 7 times the anchor height for dense soil, whereas it is approximately 5 times the anchor height for loose soil. The anchor when placed below the critical depth, settlement, and heave on the fill surface tend to be marginal. [ABSTRACT FROM AUTHOR]

The vertical pullout capacity of strip and circular plate anchors embedded horizontally in a layered sandy medium was computed by using the plane strain and axisymmetric lower-bound limit analyses in combination with finite elements and linear optimization. The soil medium below the anchor plate was assumed to be comprised of loose sand. Two different sand layers were considered above the anchor with different combinations of their internal friction angles. For several embedment ratios H=B, the variations of the pullout factors Fγ and Fq due to the components of soil unit weight and surcharge, respectively, were computed as a function of Hdense=H for different cases; here, H and Hdense imply (1) the depth of the anchor plate from ground surface and (2) the thickness of the dense sand layer, respectively. The pullout resistance increased continuously with an increase in Hdense=H. For a given H=B, with the same value of Hdense=H, the uplift resistance became greater for a case when the dense sand layer was kept just above the plate rather than placing it close to ground surface. Compared with strip anchors, the uplift factors became considerably greater for circular anchors. The effect of the variation of the unit weights of the two layers above the anchor plate on its pullout resistance was also explored. The results obtained from the analysis compare well with the available theoretical and experimental data. [ABSTRACT FROM AUTHOR]

Evaluation of the uplift capacity of plate anchors in saturated clay is an important aspect in the design of offshore foundation systems of various structures. In most of the literature reviewed, simple constitutive models such as Tresca or Mohr-Coulomb (MC) have been used in evaluating the plates' pullout capacity. There exists a need to study the pullout capacity of anchors using other advanced soil models and explore differences in computed behavior. In addition to the MC model, two other constitutive models are used herein to represent the soil behavior. These are Modified Cam-Clay and Soft Soil models. A series of finite-element analyses are performed using the three constitutive models. Undrained effective stress analyses are conducted to study the response of both strip and circular plate anchors in saturated soils. The capacities of plate anchors are assessed through the application of the displacement control approach. The effective stress parameters are correlated with the undrained shear strength, and Nc (dimensionless breakout factor) values from the three constitutive models are presented and compared with the lower bound solution, as well as with the data obtained from similar studies and experimental data available in the literature. Differences resulting from the characteristics of the three constitutive models are examined and discussed. [ABSTRACT FROM AUTHOR]

The present study addresses the effect of interference on the uplift capacity of two closely spaced horizontal strip anchors embedded in cohesionless soil. The analysis has been performed using the method of stress characteristics coupled with the limit equilibrium approach. The method consumes fewer assumptions and provides a zone in which the force equilibrium and plastic yield conditions are simultaneously satisfied for given boundary stresses. The effects of surcharge and unit weight of soil on the pullout resistance of anchors have been determined in terms of uplift capacity factors (Fq and Fγ) and are presented as functions of embedment ratio (λ) and angle of internal friction of soil (ϕ). Similarly, the interaction phenomenon of two closely placed anchors has been expressed in terms of efficiency factors (ξq and ξγ). A detailed parametric study has been carried out by varying the clear spacing (S) between two anchors, embedment ratio, and soil friction angle. The results of the numerical analysis are compared with the available theoretical and experimental data reported in the literature. [ABSTRACT FROM AUTHOR]

The uplift capacity of shallow horizontal strip anchors embedded in cohesionless soil has been obtained under seismic conditions. The limit equilibrium approach with log spiral failure surface together with modified pseudodynamic seismic forces has been adopted. In this modified pseudo dynamic approach, the soil is assumed to behave as a viscoelastic material overlying a rigid stratum and subjected to harmonic horizontal acceleration. This modified methodology satisfies the zero-stress boundary condition at the free ground surface. In the present methodology, the amplification of seismic acceleration depends on the soil properties and can be evaluated; hence, there is no need for assumption of any amplification value as is usually done in the literature. It is observed that the seismic acceleration distribution along the depth is highly nonlinear. The net seismic vertical uplift capacity factor for a unit weight component of soil (Fγd) is estimated. The results under static and seismic conditions are determined for various combinations of input parameters, such as soil friction angle, embedment ratio, and seismic acceleration. It is observed that the design value of Fγd decreases significantly with an increase in seismic acceleration. As expected, the seismic uplift capacity increases with an increase in embedment ratio and soil friction angle. Results in terms of nondimensional net seismic uplift capacity factor are presented in graphical form. In addition, the present results are compared and found to be in good agreement with a very few available similar results in literature. The present study reveals the lowest critical design values of seismic uplift capacity factor that may be used in seismic design of shallow strip anchors. [ABSTRACT FROM AUTHOR]

This paper presents numerical models and mathematical formulations to predict the pullout capacity of anchor plates with different inclination angles embedded in clay. The models were developed based on the failure mechanism deduced from laboratory testing and utilize the Mohr-Coulomb yielding criteria. Expression was given to estimate the maximum pullout resistance of plates with different dimensions and inclination angles embedded in various clayey soils. A comparison between results of finite-element analyses has been performed to find out the effect of different parameters. New two-variable functions have been presented to show the relationship between pullout resistance and embedment ratio with different inclination angles. In addition, an interesting relationship among pullout capacities of anchor plates at different inclination angles was found, and a new concept, ellipse of pullout capacity, has been pronounced. Finally, a new theory has been introduced to predict the pullout capacity of any anchor plates with different inclination angles and various depths, without any computer analysis and just by using the new proposed theory. [ABSTRACT FROM AUTHOR]

The vertical uplift capacity of an infinite numbers of rigid strip plate anchors placed in a group and embedded in sand, has been determined. An upper bound theorem of limit analysis in combination with finite elements and linear programming has been used to perform the analysis. All the anchors are loaded to failure simultaneously with the same magnitudes of the failure loads. For different clear spacing (S) between the anchors, the magnitude of the efficiency factor (ξγ) is determined; where ξγ is the ratio of the failure load for an interfering strip anchor, for given width (B) and depth (d), to that of an isolated strip anchor having the same width and depth. The magnitude of ξγ has been found to reduce substantially with a decrease in the spacing between the anchors. It was noted that a rigid soil wedge just above the anchor plate and bounded by planar rupture surfaces separates out and it moves with the velocity same as that of the anchor plate itself. The results available from the analysis were found to compare reasonably well with the available theoretical and experimental data from the literature. [ABSTRACT FROM AUTHOR]

This paper presents laboratory tests on a bond-type anchorage system and a full-scale ground anchor with fiber-reinforced polymer 9-bar tendons. A cement-based mortar filled steel tube was used to simulate a rock mass environment. Resistance strain gauges, fiber optic sensors, embedded strain gauges, and linear variable displacement transducers were used to monitor the behavior of the anchor and to study load transfer mechanism of the tendon to surrounding rock mass. The test results show that the developed bond-type anchorage performs well for post-tensing applications with the tendons. The tested anchor presents an acceptable tensile behavior for each loading stage investigated (up to a load level of 0.6ffu, where ffu=guaranteed capacity of the tendon) in accordance with existing codes. The anchor is similar in strain distribution profile to conventional steel anchors, except giving a shorter load transfer length. It is expected that the anchor require a minimum anchor bonded length of 2,000 mm with plain cement grouts. [ABSTRACT FROM AUTHOR]

This paper presents a plastic limit analysis of the lateral load capacity of suction caissons in an anisotropic, purely cohesive soil assuming conditions of rotational symmetry about the vertical or gravity axis. The formulation utilizes a form of the Hill yield criterion that is modified to allow for different soil strengths in triaxial compression and extension. Using this yield criterion, energy dissipation relationships are formulated for continuous and discontinuous deformation fields. These dissipation relationships are then applied to a postulated caisson failure mechanism comprising a wedge near the free soil surface (mudline), a two-dimensional flow-around failure at depth, and a hemispherical slip surface at the base of the rotating caisson. The plastic limit analysis predictions compared favorably to predictions obtained from finite-element simulations employing a Hill yield criterion. For the range of anisotropic undrained strength properties commonly reported for normally K0 -consolidated clays, parametric studies indicate that suction caisson horizontal load capacities predicted using a conventional approach (a von Mises yield surface fitted to the soil simple shear strength) will differ from anisotropic predictions by less than 10%. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the uplift behavior of horizontal strip plate anchors constructed at a distance to the slope crest. A series of uplift load tests was conducted in laboratory for scaled strip plate anchor models, which were buried in the horizontal ground or at different distances from a sand slope with various slope angles. Results imply that the distance from the anchor to the slope and the angle of the slope play an influential role in the failure mode and loading capacity. The loading mechanism of the strip plate anchor buried near a slope is equivalent to that of a strip plate anchor buried in horizontal ground when the edge-distance ratio reaches a critical value. The critical edge-distance ratio obtained by the proposed formula in this study is 0.9 or 1.9 for slope angles of 15° or 30°, respectively. Further, the geometric configuration of the failure surfaces can be approximated to be circular curves whose radius can be determined by the value of edge-distance ratio and slope angle. After that, an analytical method to calculate the uplift capacity considering the influence of edge-distance ratio and slope angle has been developed by using the limit-equilibrium method. All the error between the calculated results based on the theoretical solutions and the measurements from the laboratory tests is contained in 17.4% when the effect of sand dilatancy is considered. [ABSTRACT FROM AUTHOR]