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On 3 October 2013, a global failure occurred in one of the stabilised sections of a deep excavation in Shahrak-e gharb in Tehran. The excavation was supported by ground anchors with enlarged reinforced concrete thrust blocks and sprayed concrete facing. The failure occurred despite the system passing conventional limit equilibrium design and satisfying requirements in terms of allowable displacements. The case of Shahrak-e gharb was modelled using Abaqus in order to understand the soil deformation leading to the failure condition. It was found that a near-surface zone of weaker fill material was responsible for the failure. As the displacements during construction and the soil failure mechanisms were well matched by the numerical model, the case study was considered to be a validation case for the numerical model and a parametric study on the extent to which anchoring bypassed the weaker surface soil was performed. This study showed that proper embedment into competent soils is important as excessive strains can still develop if the anchor bond zone is insufficiently confined, potentially leading to progressive collapse.

The purpose of this paper is to describe the variability of soil rheological properties based on research carried out using load tests of ground anchors under complex geotechnical conditions. The heterogeneity of soil should always be considered when designing geotechnical constructions. In the present case, the earthwork created at the Warsaw Slope revealed an embankment of anthropogenic origin, located in a geologically and geomorphologically complex area of the Vistula valley slope. Excavation protection was anchored mainly in soils of anthropogenic origin. When the acceptance tests of the ground anchor were completed, the subsoil randomness was confirmed using nondirect, geostatistical methods. A standard solid rheological model with nonlinear fitting to the data was used. This model was established to describe the creeping activity of the ground anchor more accurately. The characteristics of man-made embankments were described using the parameters obtained with the rheological model of the subsoil.

This paper presents a case study and numerical simulations of a corner of a deep excavation in Tehran supported by soldier piles and ground anchors. This study focuses on the differences between 2D...

In urban areas, properly designed deep excavation support systems are essential for any new underground construction adjacent to the existing buildings. Diaphragm walls are widely used in India as deep excavation support system to facilitate strut-free excavation as well as to limit the soil movement of surrounding areas due to excavation. In this paper, a ten-story new commercial development required a three-level basement excavation of 12.5 m (max.) from the existing ground level (EGL). Project site consists of mixed soil condition with silty clay of varying consistency followed by dense sand underlain by a weathered rock layer. A 600 mm thick rectangular D wall panel with temporary ground anchors was used to support deep excavation wherever sufficient setback is available. In the same site, one of the corners has a restricted setback which demanded 8 m cantilever wall with high structural rigidity. Hence, T-shaped diaphragm wall panels of 600 mm thick were adopted as a permanent cantilever wall. Numerical modeling of the retention system was analyzed using WALLAP and PLAXIS 2D software. The wall deflections were monitored through inclinometers. This paper reviews the performance of cantilever diaphragm wall and rectangular panel wall with single anchor for 8 m excavation depth. Cantilever T-shaped diaphragm wall proved to be effective and stable system, where tie back is not feasible.

This study evaluates load variations in instrumented prestressed ground anchors installed in a bored pile retaining wall system in sandy soil. Data were collected from instrumentation assembled in the bonded length of three anchors, which were monitored during pullout tests and during different construction phases of the retaining wall system. Instrumentation consisted of electrical resistance strain gauges positioned in five different sections along the bonded length. Skin friction distributions were obtained from the field load measurements. Results showed that the skin friction followed a non-uniform distribution along the anchor bonded length. The mobilized skin friction concentrated more intensely on the bonded length half closest to the unbonded length, while the other half of the bonded length developed very small skin friction. The contribution of the unbonded length skin friction to the overall anchor capacity was significant and this should be accounted for in the interpretation of routine anchor testing results. Displacements applied to the anchor head were sufficient to mobilize the ultimate skin friction on the unbonded length, but not on the bonded length. Performance of loading-unloading stages on the ground anchor intensified the transfer of load from the unbonded length to the bonded length. Long-term monitoring of the anchor after lock-off revealed that the load at the anchor bonded length followed a tendency to reduce with time and was not significantly influenced by the retaining wall construction phases. resumo: O presente estudo avalia as variações de carga em ancoragens protendidas instrumentadas, instaladas em uma estrutura de contenção composta por estacas escavadas em solo arenoso. Os dados foram coletados a partir de instrumentação disposta no trecho ancorado de três ancoragens, monitoradas durante ensaios de arrancamento e durante diferentes etapas construtivas da contenção. As ancoragens foram instrumentadas com extensômetros elétricos de resistência em cinco seções distintas posicionadas ao longo do trecho ancorado. Distribuições de atrito lateral foram obtidas a partir das medições de carga em campo. Os resultados revelaram uma distribuição não uniforme do atrito lateral ao longo do trecho ancorado. O atrito lateral mobilizado concentrou-se mais intensamente na metade do trecho ancorado mais próxima ao trecho livre, ao passo que uma parcela muito pequena de atrito lateral foi mobilizada na outra metade do trecho ancorado. A contribuição do atrito lateral no trecho livre para a capacidade de carga da ancoragem foi significativa, o que deve ser levado em consideração na interpretação dos resultados de ensaios de rotina em tirantes. Os deslocamentos aplicados na cabeça da ancoragem foram suficientes para mobilizar o atrito lateral último no trecho livre, porém não no trecho ancorado. A execução de estágios de carga-descarga na ancoragem contribuiu para intensificar a transferência de carga do trecho livre ao trecho ancorado. O monitoramento de longo-prazo da ancoragem após incorporação do carregamento revelou que a carga no trecho ancorado seguiu uma tendência de redução ao longo do tempo, não tendo sido significativamente influenciada pelas etapas construtivas da contenção.

The article describes the technical features and advantages of using screw anchors in transport construction. Ground anchors with screw piles are assumed to be the best anchor design currently in use. It is known that screw piles not only do not violate the soil during immersion, but, as shown by numerous tests, soil compaction occurs. The design of a pile-screw anchor of increased horizontal susceptibility is presented, which allows to increase the carrying capacity of a conventional screw pile, with expansion of the functional capabilities of the screw anchor as a whole. In particular, the article discusses a method of determining the bearing capacity of a pile-screw anchor of increased horizontal stability. Method of analytical calculation of its bearing capacity on horizontal loads is given. The essence of the calculation method consists in determining the values of the bearing capacity of its structural elements: a screw pile for pulling out and a thrust plate for compressing on the ground under the influence of a horizontal load. It is assumed that this method allows theoretically determining the maximum permissible horizontal load on the pile-screw anchor. Theoretical recommendations on application of pile-screw anchor in different soil conditions are given.

The paper presents the results of the monitoring of construction for the unique residential building of 310 m high with 4-storey underground parking. One of the unique projects is the housing estate called “Abu-Dhabi Plaza” which started in 2011 in Nur-Sultan city. High-rise buildings pose new challenges for engineers, especially in the design of above-ground structures, bases, and foundations. The basement walls are formed with reinforced concrete diaphragm wall panels, which were supported with ground anchors. The shoring system analyses had been designed using PLAXIS 2D, which can assess in detail of the deformations that occur in soil. In the course of excavating a thick layer of soft, weak soil in St. Petersburg, Russia, instabilities were encountered in a 21 m long sheet pile excavation fence made of AU Arcelor 18. In light of the rather large depth (12 m) and areal extent (150 m by 80 m) of the excavation, such instabilities presented a significant challenge for the geotechnical engineers. This paper reviews the results of soil property tests performed in conjunction with the construction of the aforementioned large excavation, as well as the neighboring buildings. The need for continuous monitoring of geotechnical conditions using the methods of static sounding, to assess the zone of construction influence and to forecast the mutual influence of the structure being constructed on the surrounding buildings, is discussed. Finally, the raft foundation has recommended for future high-rise buildings to be constructed on competent residual soils.

In Taiwan, the landforms are mainly dominated by mountains and hills. Thus, countless road sections of the freeways are impossible to avoid the state-of-the-practice problems such as slope cutting. In order to stabilize the freeway slope, ground anchor technique is often employed to improve the stability of cut slope. With the increasing service time of ground anchors, their performance on the freeway slopes is highly required to be assessed. There were many disasters on freeway anchored slopes in recent years, so ground anchor inspection has also received attention to a great extent. This paper introduces the concept of safety potential analysis and then utilizes the proposed model for an anchored slope. Specifically, the proposed safety potential analysis collects plain map, historical slope inspections, monitoring data, ground anchor inspections and maintenance practices, as well as further use the geographic information system to establish the proposed model. Finally, this paper provides the predicted result from safety potential analysis and suggests the dangerous area of the studied anchored slope to the government authorities for immediately response purpose.

Paper brings a review of creep slope movement phenomena, its damage to structures, and the applied stabilization techniques in urban locations. The holistic approach to such locations based on proper ground investigation and design of preventive and remedial measures is presented on three case studies in Brno, Czech Republic. The need to respect the given geological conditions is emphasized. The related non-structural preventive measures (preventing infiltration, not undercutting the slope toe), and structural remedial measures (underpinning, anchored pile walls) application in the specific condition are described. The process of numerical analysis of strengthening pile retaining wall supporting the cut constructed in the lower part of the sliding body is presented. The importance of residual soil strength parameters for analysis of landslides is emphasized also.

With increasing level of urbanization, new buildings are erected in close proximity to existing buildings or quite close to site boundaries. Such practice affects the complexity of retaining wall installation technology. When a retaining wall is installed close to an existing building, a street or a steep slope, the stability of the wall has to be ensured first. There are cases when a retaining wall has to be strengthened by creating a permanent or temporary support, i.e. by installing ground anchors. According to literature analysis, the major problem is that a profile stops without reaching its designed depth (Van Baars). Merifield et al. distinguish three major types of anchors: circular, square and rectangular. They emphasise that anchor surface unevenness does not impact anchor resistance. According to Nagar, most frequently anchors disintegrate due to excessive tensile strength of the anchor. The increase of this force is related to tensile strength measured in anchor testing. In this paper, three types of retaining walls with ground anchors are considered: pile wall, Berlin Wall, and sheet piling with excavation depth of 6 m. The conditions are selected as follow: when walls are installed in clay soils, sandy soils, sandy soils at high groundwater levels, and when the wall is installed next to the building. Mechanical resistance and stability of construction incline are calculated by means of GEO5 software. A survey was designed basing on the calculation results and the selected evaluation criteria. In the survey geotechnical engineers rated 18 different cases. The relevance of criteria is determined by employing the entropy method after the primary results of the survey are summarised; afterwards a multiple criteria decision analysis carried out using the utility function. The multi-criteria assessment results indicate the most rational type of a retaining wall for the chosen conditions. This article is based on master thesis topic “Research on Installation Technologies of Retaining Walls with Ground Anchors”.

Current permanent ground anchor standards require the use of double-protection systems encapsulating the steel strands, in order to ensure a serviceable design life. In recent years, where steel reinforcement use was restricted due to aggressive ground conditions, carbon-fibre-reinforced polymer (CFRP) reinforcement was successfully used as a durable construction alternative. While CFRP strands have been researched and developed for use in prestressed concrete members such as bridge construction, minimal research has been devoted to developing CFRP strands for use in high-capacity ground anchors. This paper presents research work investigating CFRP strand performance when exposed to extreme aggressive environments. A series of 6-month-long experiments were conducted in an unstressed state, studying the absorption and physical effects as well as the ultimate tensile performance of the CFRPs over a range of accelerated conditions including temperature (30 and 60°C) and aggressive solutions (alkaline, acidic). Based on experimental results, the levels of corrosion protection systems required for CFRP anchor systems are critically assessed. The results highlight the importance of identifying the CFRP strand resin matrix before it can be implemented in a ground anchor system.

Cable yarding systems transport logs hoisted off the ground by a system of cables and a carriage that moves along the cable. Ground anchors are used at the end points to maintain sufficient tension between the two ends points of the cable and keep it in the air during operation. Traditional anchoring methods employ tree stumps, but as shorter stand rotations result in younger weaker stumps and because of the inability to visually inspect root structures to calculate a stump’s anchoring capacity, alternative methods of anchoring are being used more frequently. In this paper, the capacity of an alternative anchoring method, known as equipment anchoring or mobile anchoring, is assessed for guyline and skyline applications. Some critical components that are observed to influence anchor capacity are equipment weight, slope, blade embedment, angle of cable pull, and soil type. An analytical design solution for mobile anchor capacity is compared with the results of over two dozen field tests to determine the effectiveness of predicting anchor capacity. In addition to estimating the capacity of mobile anchors, a relationship between skyline and guyline loading recorded on harvest operations is analyzed.

Securing of temporary hydrotechnical structures (water-filled, panel-mounted, and other types of dikes) of different heights by means of flat earth anchors and screw piles designed to protect population centers and infrastructure against large-scale floods is considered.

Ground anchors represent an important structural element in the area of geotechnical engineering. Despite their extensive usage, a design process of these elements is usually performed using simple empirical and semi-empirical methods, neglecting several important influencing factors. This paper gives an analysis of the factor of non-uniform distribution of skin friction resulting in a progressive failure of ground anchors. First, the finite element method in combination with a material model involving regularized strain softening is utilized. Next, an experimental program, including several investigation anchor load tests, was carried out. The goal of this program was to confirm preliminary conclusions drawn from numerical studies and to obtain relevant data for further back analysis. After, there is then described a newly developed application based on the load transfer method, in which all the findings from numerical computations and experimental measurements are incorporated.

A series of dynamic centrifuge model tests was conducted to investigate the effects of reinforcement on the seismic behaviour of hillside embankments consisting of sandy soils and resting on stiff base slopes. In total, three types of seismic reinforcements, namely, large-scale gabions, drainage-reinforcing piles, and ground anchors with pressure plates, were employed in the tests. The test results showed that: (1) the seismic performance of both lower and higher embankments was remarkably improved by installing large-scale gabions at the toe as they restrained the completion of the formation of sliding planes; (2) the installation of drainage-reinforcing piles at the embankment toe was rather effective in reducing the overall earthquake-induced deformation due to their high permeability and restraint effect against sliding displacement at the reinforced region; and (3) the embankments improved by ground anchors with pressure plates were not vulnerable to earthquake-induced damage due to their constraint effects even under high water table conditions. The improvement effects by the above-mentioned three types of reinforcements were presented by evaluating the global safety factors based on the results of a series of triaxial compression tests.

A ground anchor is used to withstand tensile stresses caused by loading both the natural load of the soil and external pressures, then passing the force into the ground. It is generally used to retain tensile form and lateral power structures in constructing walls, foundations, transmission towers, pile, floating docks, mooring dolphin, and offshore buildings. Various ground anchors have been widely used, such as drag, helical, circular-shaped plates, and squares. Especially for massive plate anchors, installation is complicated because it must be excavated first before installation. A challenge in engineering is especially on cohesive soil conditions (soft soil). With these considerations, it is necessary to develop innovative models that are easier to install but still have a large enough tensile capacity. This research analyzes the tensile capacity by using ground anchor folding type to overcome building problems on cohesive soil. The test was tensile capacity with four leaves and a Variation of depth-the performance of this folding type anchor based on the tensile capacity and the anchor. The results obtained in this study; the greater area of the element occurred a significant increase in tensile capacity.

Guler, Erol/0000-0002-3492-387X; WOS:000445635700006 In this study, pullout performance tests were conducted on five prestressed ground anchors having different tendon bond and unbonded lengths. The tendon bond lengths of the tested anchors varied from 4 to 10m, whereas the unbonded lengths were in the range of 8-16m. The tests were performed separately on a dense, gravelly sandy soil slope with an inclination of 90 degrees in Cottbus, Germany. The anchors were inclined downwards at an angle of 15 degrees below the horizontal. The results indicated that three of the five anchors did not satisfy the acceptance criteria as outlined in DIN 4125 Standards. According to the acceptance criteria, the line that was composed of the elastic displacements of the unbonded length had to remain between two specific limit lines. Although the elastic displacements of the unbonded tendons were taken into account for the acceptance of the anchors, the length of the unbonded tendon did not have a significant effect on stability. The anchors having unbonded lengths of 8, 13, and 15m failed, whereas the anchors with unbonded length of 9 and 16m were accepted after the termination of the performance tests. However, the tendon bond length was proved to be an important parameter that contributed to the acceptance of the tested anchors. Test results indicated that anchors having tendon bond lengths longer or shorter than 6m were rejected.

This paper, consisting of full-scale pullout tests and theoretical analyses, focuses on the behavior of ground anchors under ultimate load conditions. Three ground anchors with a bonded length of 4 m were built in slightly weathered limestone and tested until their ultimate load capacities were passed. The test data indicated that two of the anchors performed well with the ultimate load capacities being nearly 3 times of the design values. The remaining anchor performed below expectation, which was diagnosed of poor grouting. Furthermore, an analytical framework was developed considering the elastoplastic stress-strain relationship at the anchor-rock interface. The developed model revealed that the bond stress was not uniform along the entire bonded length when the ultimate state was reached; instead, the bonded length was composed of plastic and elastic zones. The length of elastic zone was not significantly influenced by the increased load, while the plastic zone extended with the increase of the load. The average ultimate bond stress over the entire bonded length was a function of anchor diameters and bonded length. Thus, current recommended presumptive ultimate bond stresses should be used with caution if the anchor is very short ( 12 m).

In this paper, the stabilisation of a 60 m-high natural slope located in Fujian Province in southeast China is analysed using finite-element and limit equilibrium methods. The strength reduction finite-element analysis was able to capture the behaviour of the slope before stabilisation and its performance after stabilisation. The factors of safety obtained with the two different approaches are compared and discussed in this paper. Deformation analysis was also conducted to investigate the serviceability of the slope during the stabilisation construction activities. The results show that the combination of slope flattening and ground anchors was able to provide the required stabilisation while satisfying serviceability requirements, as the deformations at the crest and toe of the slope were within tolerable limits.

An anchored sheet wall is commonly used in retaining deep excavations. Anchor force is one of the critical design parameters in practice. Based on the kinematical admissible failure mechanism, a limit analysis approach to determine the anchor force is presented. The explicit formula for the anchor force is given, which makes it easy to calculate using a simple calculation program such as MS Office Excel. Anchor force is mainly influenced by seven parameters: the internal friction angle; cohesion of the soil; wall friction angle; surcharge on the ground surface; dip angle of the anchor; penetration depth of the wall; and depth from the anchor force action point on the wall to the ground surface. The relevant quantitative calculation can be performed by the proposed method. In addition, the design anchor force under a specified design safety factor and the anchor forces of multiple rows of anchors are also illustrated in this paper. To verify that the method is reasonable, the predicted and measured anchor forces are compared in two classical soil-nailed wall experiments. The result shows that the presented method is applicable.

This paper deals with numerical and experimental investigations of specific problems of guided wave propagation in ground anchors, focussing on recognizing the phenomenon of the energy transfer between anchor components. Particular attention is paid to characteristic features of guided waves propagating in free and embedded parts of the tendon, at the interface between the tendon and the surrounding anchor body, as well as waves diffracted on the start of the anchor body. Anchors with variable lengths and diameters of the anchor body, as well as anchors with non-reflecting boundary conditions, are analysed numerically. Experimental measurements are conducted on laboratory models of ground anchors of different fixed lengths. The study shows that the detailed recognition of the phenomenon of the transfer of the wave energy between the tendon and the anchor body is crucial for the appropriate application of the guided wave propagation method for non-destructive inspection of ground anchors. The obtained results indicate that the three most important geometric parameters, i.e. the anchor body length, the free length of the tendon and the thickness of the anchor body, can be determined on the basis of wave propagation signals recorded at the free end of the anchor.

In this research, pull-out experiments of model flip-type ground anchors (flip anchor, hereafter) were conducted in two-dimensional (plane strain) condition to investigate the fundamental pullout mechanisms of flip-type ground anchor. A transparent acrylic soil box was used as a soil box. Rectangular model flip anchors had the depth of 98 mm, and breadths, B, of 48 mm or 80 mm, so that the depths of the soil box and the model anchors were the same. The anchor was buried in the dry sand model ground and pulled-out. The experiments were carried out by changing embedment depth, h, initial positions of the anchor head (open or closed), and width of anchor head, B. Pull-out force, F, and pull-out displacement, w, were measured. The ground movements were observed using a PIV analysis. Based on the image analyses, ground failure pattern was simply modelled. The model simulated the tendency of the experimental values well. It would be expanded to three-dimension to design actual flip-type anchors.

Ground anchors have been playing an important role in reinforcing dykes, underground, stabilizing structures of earth retaining walls, subway stations, and anchoring abutments of bridge or in sea port, etc. In Vietnam, the design of ground anchors is generally based on the international design guidelines, in particular the Eurocode. As there is a diversity of current design practices in different countries, it is necessary to carefully verify and validate an international design of ground anchor before adopting it to Vietnam. This paper aims at presenting a series of full-scale pullout tests of ground anchors recently performed in several projects in Hanoi and Ha Long city, Vietnam. The testing results in terms of the ultimate load-holding capacity, the pullout performance and the skin friction are discussed and compared with the French design practice TA95 in order to evaluate as well as to improve its applicability in Vietnam.

Fully grouted ground anchors have been increasingly used as a part of foundation system to resist buoyant force in geotechnical practice. However, designs of fully grouted anchors are commonly based on the calculation of the ultimate pullout capacity along with safety factors, which results in unnecessary economic loss. This is partly due to the fact that it is impractical to predict the anchor performance without strong assumptions of how steel tendons, soils, rock, and grout can collectively resist pullout force or without detailed information of the ground parameters. As one of the promising fields within the framework of artificial intelligence, Machine Learning (ML) has been increasingly used to address geotechnical problems by giving computers the ability to learn without being explicitly programmed. Multivariate Adaptive Regression Splines (MARS) is an ML nonparametric algorithm that is based on a data-driven process. This paper presents the development of a MARS performance prediction model using data from 530 anti-floating anchor pullout tests in 8 different projects in weathered soils and rocks located in Shenzhen, China. In this study, MARS demonstrates the capabilities to capture the complex non-linear relationships in the anti-floating anchor pullout problem. In addition, it is shown that the displacement-based design procedure of the anti-floating anchor based on the MARS model is feasible if appropriate safety factors are adopted.

Drag anchor is an economical foundation option for offshore floating structures. Although there are studies on ultimate pullout capacity of drag anchors, the drag-in installation process is still not fully understood. The approach using yield envelopes for drag anchor under combined loading for the installation behavior prediction is promising. However, more needs to be done to understand anchor bearing behavior during the installation process. The current study focuses on the capacity of drag anchor under uni-directional vertical, horizontal and moment loading in uniform clay and the behavior of anchor fluke under combined loading. Finite element analyses are conducted for “wished-in-place” anchor fluke. The effect of anchor embedment depth and soil overburden pressure is investigated. The horizontal and rotational capacity factors for different embedment ratios and overburden pressure ratios, which have not been covered in the existing studies on anchor capacity, are provided here. The effect of anchor/soil interface breakaway condition on the capacity under the three uni-directional loading is also studied. Based on the understanding of drag anchor capacity under uni-directional loading, its behavior under combined loading is characterized by the yield envelopes for both shallow and deep anchor behavior. The current study provides a good understanding for the capacity of drag anchors. The yield envelopes can be used for the prediction of anchor trajectory with consideration of both shallow and deep anchor behavior.

The practice of design shows that the need to develop explanations, recommendations and examples of calculations to go with the essential requirements of the building rules. The author has set the task to simplify the use of the requirements for the design and construction of soil bases for cylinder open caissons. The objective of the work is to develop the fixing design of an underground structure of 24 m in diameter and 15.6 m in height, immersed in an antifriction jacket below the groundwater level to depth of 16,8 m, to prevent it from floating up. The article describes the geological structure and soil characteristics of St. Petersburg, a characteristic feature of which is the presence of groundwater horizons in the soils, complicating underground constraction. Recommendations and explanations are given as to how to forecast the forces of friction at the point of contact between the structure and the water-saturated soils. The constractive scheme of securing embedded structure from floating up has been developed. The methods of calculation and design of additional loads and ground anchors is described in detail. The results of calculation and analysis have been performed to verify the probability of the open caisson floating up due the action of the hydrostatic load. The main types of construction work are cementation of the antifriction cavity, building on the perimeter of the well of a reinforced collar rigidly connected with the front shaft, providing a sandy backfill as additional load for the well, anchoring the bottom of the well using vertical ground anchors. The paper may be of interest to designers working in the area of the design of underground structures.

Construction cranes are subject to a variety of external factors that affect stability and safety. Modern solutions do not provide sufficient stability and safety. To eliminate the threat from various factors, new support elements have been proposed. To assess the effect of soil anchors on the stability of a crane, a theoretical experiment was conducted, with various assumptions. The coefficient of cargo stability with ground anchors is determined and compared with the load stability factor with standard outriggers.

Vorgespannte Anker werden vorrangig zur Einleitung von hohen Zugkräften verformungsarmer Konstruktionen in den Untergrund verwendet. In der Praxis zeigt sich, dass oftmals Missverständnisse zur grundsätzlichen Wirkungsweise und zum Tragverhalten herrschen, womit derartige Anker häufig nicht bestmöglich eingesetzt werden. Im gegenständlichen Beitrag wird das System Boden-Anker durch ein gekoppeltes Federmodell abgebildet und die einzelnen Phasen – das Vorspannen sowie das Aufbringen äußerer Kräfte auf das System – grafisch anhand des aus dem Stahlbau für die Berechnung von vorgespannten Schraubenverbindungen bekannten Vorspanndreiecks dargestellt. Anhand des vorgestellten Modells wird insbesondere gezeigt, welchen Einfluss das Steifigkeitsverhältnis zwischen der durch den Boden repräsentierten Feder und jener des Ankers auf die Verteilung der Kräfte im System haben. Damit können auf einfachem Weg grundlegende Aussagen zum Tragverhalten und zur Dimensionierung vorgespannter Anker getroffen werden.

To solve the anti-float problems of underground buildings (structures) more economically, environmentally and effectively. The paper putted forward a construction technology of revolving conical pullout anchors based on researching and improving to the traditional pullout measures. That was a method that the conical anchor head was installed on the drilling pipe and screwed into the stable soil under the influence of drilling pipe. When pulling the drilling pipe, the fine aggregate concrete were poured into the edge. Furthermore, prestressed anchor cable should be strained which connected with the anchor head to keep a good connect with the beam so that it could improve pullout capacity. The conundrums of long construction period and high cost had effectively solved. This technique also had provided great reference values for the congener construction.

Torpedo anchors are used for station keeping of floating offshore platforms and fixing risers to the seabed in deep water. Their main benefit over other anchors is reduction in anchor installation cost via free falling in the water. A torpedo anchor has a steel cylindrical shaft with a conical tip and is ballasted in order to deepen the soil penetration and increase the anchor holding capacity. In order to address the installation effects on the soil strength and consequently the anchor pull-out capacity, first reconsolidation (set-up) of soil next to the anchor after installation is studied by a finite-element (FE) analysis of coupled deformation and fluid flow in porous media. The results of the set-up analysis indicate the rate of dissipation of excess pore-water pressure and soil-strength recovery. These are important considerations in predicting the anchor pull-out capacity at different times after installation. In the absence of a documented complete set of installation and set-up tests, the results are validated qualitatively using available albeit limited field test data.

Rapidly erectable, folding structures comprised of sandwich panels offer light-weight, energy efficient sheltering solutions. Field implementation requires better understanding of the impact of the erection conditions and fabrication errors on behavior, including (1) out-of-level ground conditions, (2) number/location of ground anchors, and (3) fabrication-related warping of panels. This paper investigates the behavior of a folding sandwich panel (fiber-reinforced polymer faces and foam core) structure using an experimentally validated finite element model to perform parametric studies that focus on variable out-of-level ground conditions, anchorages, and panel warping. Ultimately, this paper addresses research gaps required for field implementation and provides design recommendations.

In the present investigation, an attempt is made to explore the seismic response of two closely-spaced horizontal square and rectangular ground anchors embedded in non-homogenous c – soil deposit at different depths. The analysis is performed by using three dimensional finite difference program FLAC3D. Each anchor carries equal static safe working load without violating the ultimate uplift capacity under static condition. The soil is assumed to obey the Mohr–Coulomb failure criterion. The behaviour of single isolated anchor subjected to seismic loading is determined first to study the interaction effect between two nearby anchors. The horizontal acceleration response obtained from the Loma Prieta Gilroy (1989) earthquake is considered as the input horizontal excitation in the analysis. A parametric study is performed by varying the clear spacing (S) between the anchors at different embedment ratios (). The magnitude of vertical displacement of anchor plate, normal and shear stress developed at the anchor ...

The performance of retaining walls in Dublin Boulder Clay under undrained conditions is relatively well understood. These structures show very modest lateral movements; this is attributed to the inherent strength and stiffness of the boulder clay and the very slow dissipation of excavation-induced pore water suctions. There are few data available on the long-term behaviour of such walls, however, both in Dublin and elsewhere. The economic downturn in Ireland provided a unique opportunity to improve understanding of the long-term behaviour of these types of excavations. Several temporary works retaining walls remained in place for long periods due to work on the projects having been suspended. The paper gives details of several such projects but focuses on the performance of the 14 m high secant piled wall with a single row of ground anchors at Heuston South Quarter. It was designed as temporary works but remained in place for about 7 years, with movements increasing to over 50% more than those predicted at design stage. The paper will present a detailed account of the Heuston wall design, construction and performance and the subsequent remedial works, which were carried out to ensure its long-term stability.

In this study, we analyzed the methods and technologies used for constructing earthworks and military engineering in the latter period before the industrial revolution in Poland. The research object, the Warsaw Citadel, is a source of knowledge about military heritage from the aspect of conservation and protection of specific engineering achievements, which were dictated by early Russian geopolitical doctrine. Within the framework of the ongoing project of material heritage protection and popularization of history, the fortress has been transformed into a modern museum building. The new symbolic message of architecture was redefined, leaving behind the gloomy dominance elements in the scenery of the nearby city. In this study, reception tests of ground anchors were used for analysis. They were treated as a tool to determine the heterogeneity of fortification of historical earthworks. In the presented calculation procedure, limitations in the availability of geotechnical tests were overcome. Geological terrain layout and embankment excavation technology significantly impacted their quality and reliability. Currently, the embankments are slashed with anchored retaining walls. Ground anchors were used at short distances and were tested according to the national standard procedures. The results of the load tests are based on the physical properties of the subsoil, the conditions of contact with the supporting elements of the anchors, and the material properties. The soil interaction with the anchors is described using a rheological model, the constants of which were obtained using a fractional derivative model. The spatial variability of the rheological model parameters is presented using theoretical semivariograms matching the empirical data. The semivariograms explain the spatial correlation of the tested constants of the rheological model of the substrate with the anchors. The results of non-destructive testing were influenced by factors such as time and consolidation processes. The obtained results allowed us to directly draw conclusions about the repetitiveness of embankment features and indirectly about the quality of their construction.

The article describes the features of modeling monolithic trench “diaphragm wall” with ground anchors without the use of distribution beams on the progressive collapse caused by the failure of one of the anchors. In the simulation of the above calculation case, in the flat formulation commonly used in practice, it is assumed that the “diaphragm wall” is a continuous structure in the longitudinal direction, without taking into account the presence of vertical joints formed between the grippers when concreting the fence and the lack of connection between the longitudinal reinforcement of adjacent reinforcement spatial frameworks. The performed calculations show that the failure to take into account these circumstances leads to a significant reassessment of the ability of the “diaphragm wall” to redistribute the load from the broken anchor to the neighboring anchor and can lead to an incorrect assessment of the results of the calculation for a progressive collapse. The need to take into account the reduction of structural rigidity of the “diaphragm wall” due to the formation of cracks in two directions is also shown.