Search

As an emerging foundation structure for offshore wind turbines, bucket foundations with superior bearing capacities and efficient construction procedures have attracted significant attention in China. Thick-walled bucket foundations with concrete skirts can effectively reduce the cost and prevent the buckling problem of steel skirts during construction, transportation, and installation. However, great challenges are encountered during the sinking process, and the accurate calculation of sinking resistance is a critical process. Static-pressure tests of thin-walled and thick-walled models in sand were performed to measure the penetration resistance and soil pressure at the sidewalls and ends. The horizontal-soil-pressure coefficients of different models were calculated, and the end and skin-friction coefficients in the cone-penetration test method are recommended. The drag-reduction effects of the anti-drag ring and pressure-pull-out loading method were examined, and the drag-reduction effect was evident for the bucket foundation. The drag-reduction effect of the pressure-pull-out loading method is mainly reflected in the end zone. [ABSTRACT FROM AUTHOR]

The increase in losses in the inlet device leads to an increase in specific fuel consumption. When integrating the inlet device and the propeller or propfan, it is necessary to take into consideration their interaction to ensure the maximum efficiency of the power plant. The object of this study is a coaxial propfan with the channel of the inlet device. The results reported here are of practical value: a methodology for designing a bucket S-shaped channel of the inlet device of a power plant with a turboprop engine has been developed. The dependence of the coefficient of preservation of the total pressure of the inlet device on the height and speed of flight was obtained, which makes it possible to take into consideration the influence of the propfan of a turboprop engine. A comparison of the characteristics of the ring-type and bucket S-shaped channel of the inlet device of the power plant with the turboprop engine was carried out. Specifically, it was found that the change in flight conditions has a less significant effect on the change in the coefficient of preservation of the total pressureof the ring-typeinlet device than the bucket one. A comparative assessment of the obtained results of mathematical modeling of the flow in the bucket S-shaped channel of the inlet device, taking into account the influence of the propfan, with the results of flight tests of the ring-type inlet device of the prototype is given. The comparative evaluation shows that the use of a bucket inlet device, instead of a ring-type inlet device, makes it possible to increase the full pressure recovery factor by 5–7 %. Thus, there is reason to argue that replacing the ring-type with a bucket inlet device will minimize hydraulic losses at the inlet to the engine and reduce the uneven flow at the inlet. That, in turn, will improve engine efficiency. [ABSTRACT FROM AUTHOR]

In this work we analyse bucket increasing tree families. We introduce two simple stochastic growth processes, generating random bucket increasing trees of size n, complementing the earlier result of Mahmoud and Smythe (1995, Theoret. Comput. Sci.144 221–249.) for bucket recursive trees. On the combinatorial side, we define multilabelled generalisations of the tree families d-ary increasing trees and generalised plane-oriented recursive trees. Additionally, we introduce a clustering process for ordinary increasing trees and relate it to bucket increasing trees. We discuss in detail the bucket size two and present a bijection between such bucket increasing tree families and certain families of graphs called increasing diamonds, providing an explanation for phenomena observed by Bodini et al. (2016, Lect. Notes Comput. Sci.9644 207–219.). Concerning structural properties of bucket increasing trees, we analyse the tree parameter $K_n$. It counts the initial bucket size of the node containing label n in a tree of size n and is closely related to the distribution of node types. Additionally, we analyse the parameters descendants of label j and degree of the bucket containing label j, providing distributional decompositions, complementing and extending earlier results (Kuba and Panholzer (2010), Theoret. Comput. Sci.411(34–36) 3255–3273.). [ABSTRACT FROM AUTHOR]

The final and third bucket is the patient, their pathophysiology, clinical status and the task/s pertaining to that patient's care. Since its origins during times of antiquity, the basis of surgical practice and teaching has largely been focused on the mastery of technical skills. The underlying concept is retained, however in place of "task" this has been replaced by "patient" to consider not just the tasks required for the patient, but the inherent patient-related factors. Applying the "three buckets" theory of situational awareness to surgical training: an updated framework. [Extracted from the article]

In this paper, we describe a prototypical crawler vehicle developed for "Hairo Sozo Robocon," i.e., the 4th creative robot contest for decommissioning conducted in 2019. The rules of this robot contest required a high turning ability on a flat floor and high mobility through the inner space of a pipe. In addition, the robot needed to salvage objects from a floor placed 3.2 meters underneath itself. We developed a multi-articulated tracked vehicle to provide high mobility in both contexts. The vehicle was equipped with a sensorless salvaging bucket inspired by a traditional sampler sounding weight. [ABSTRACT FROM AUTHOR]

The current practice for estimating the penetration resistance of suction bucket foundations requires breaking down the penetration resistance into tip and skirt resistance components. Cone penetration test (CPT)-based methodology correlates these components to the cone resistance measurements through empirical coefficients. In this study, an experimental campaign involving suction installation, jacking, and pullout tests on suction buckets with a large aspect ratio (i.e., L/D = 1, where L is the skirt length and D is the diameter) atop sand deposits of varying relative densities was performed to identify the important factors that are involved in the installation procedure but are not well understood. The following factors were studied: the influence of the friction area in caissons of round and modular shapes, the dilative behavior of sand, the soil–structure interface friction angle, and the penetration depth. The experimental results of the jacking installation tests indicated that a larger friction area significantly increased the penetration resistance; however, this effect was completely diminished when foundation suction-assisted penetration was used. Based on these results, modified friction resistance and tip resistance factors in the empirical expressions accounting for the relative density and penetration depth were proposed. Finally, the required suction pressure was back-analyzed by utilizing these empirical relations, reduction factors, and the critical pressure. [ABSTRACT FROM AUTHOR]

Suction bucket foundation is a novel and cheaper foundation used in marine structures, such as offshore wind turbines, breakwater and oil platforms. Compared with a single bucket foundation, tetrapod bucket foundations can bear larger loads because of the group effects. However, the vertical, horizontal and moment capacity factors of tetrapod bucket foundations have not been presented in existing specifications. A series of three-dimensional finite-element analyses were conducted to investigate the group effects on uniaxial capacities and failure mechanisms of tetrapod bucket foundations in undrained clay considering various foundation separation distance ratios, embedment depth ratios, soil-strength heterogeneity indices and load direction angles. Generalized formulas for undrained uniaxial capacities of tetrapod bucket foundations were proposed in order to establish a bridge connecting the capacities of tetrapod bucket foundations and those of the single bucket foundation, which can provide a reference for industrial designs of capacities of tetrapod bucket foundations. The results show that the vertical group effect factor of tetrapod bucket foundations is basically not affected by the foundation separation distance ratio, embedment depth ratio, soil-strength heterogeneity index and load direction angle, which can adopted 0.9 based on a conservative estimation. The normalized horizontal and moment group effect factors of tetrapod bucket foundations are both affected by the separation distance ratio, embedment depth ratio and soil-strength heterogeneity index, but the moment group effect factor is also obviously affected by the load direction angle. The value of the horizontal and moment capacity factors of tetrapod bucket foundations are about 2.3 and 13.8 times that of a single bucket foundation, respectively, when the separation distance ratio is 3.5, embedment depth ratio is 1.0 and soil-strength heterogeneity index is 10, which have both been significantly enhanced. A value of 3.5 is suggested for the separation distance ratio to attain good capacities and a relatively high global stiffness for the tetrapod bucket foundations. [ABSTRACT FROM AUTHOR]

Reinforcement Learning (RL) requires many interactions with the environment to converge to an optimal strategy, which makes it unfeasible to apply to wheel loaders and the bucket filling problem without using simulators. However, it is difficult to model the pile dynamics in the simulator because of unknown parameters, which results in poor transferability from the simulation to the real environment. Instead, this paper uses world models, serving as a fast surrogate simulator, creating a dream environment where a reinforcement learning (RL) agent explores and optimizes its bucket-filling behavior. The trained agent is then deployed on a full-size wheel loader without modifications, demonstrating its ability to outperform the previous benchmark controller, which was synthesized using imitation learning. Additionally, the same performance was observed as that of a controller pre-trained with imitation learning and optimized on the test pile using RL. • Created a fast simulator for the bucket filling problem using world models and data from operators. • Optimized a controller in the fast simulator and deployed it directly to the machine. • The optimized controller outperformed benchmark methods in a field-test. [ABSTRACT FROM AUTHOR]

• • Syphons perturb tip-times in many rain gauges. • • Short-term intensity cannot confidently be estimated. • • Syphon artefacts arise at intensities <2 mm h−1 to >300 mm h−1. • • In short-term intensity studies, the syphon should be removed. Tipping-bucket rain gauges (TBRGs) are widely used globally to record rainfall amounts over nominated accumulation durations such as 15-minute rainfall, hourly rainfall, and daily rainfall. To reduce the under-estimation of rainfall amounts that results from high rates of inflow to the tipping buckets in intense rainfall, small syphons are commonly installed between the rain-collecting funnel and the bucket mechanism. The syphon is designed to regulate the inflow, reducing the systematic error inherent in the basic TBRG mechanism. The inter-tip times (ITTs) of a TBRG are often used as a source of rainfall intensity data, since the ITTs provide the highest temporal resolution possible from such gauges. However, the influence of the syphon is generally neglected in this approach to intensity estimation. Experimental results are presented here from a high-quality TBRG fed with known rates of water inflow, simulating rain of various constant intensities. Tests were replicated with the syphon installed, and with it removed. Results confirm that the syphon significantly perturbs the sequence of ITTs, causing apparent fluctuations in intensity that do not in fact exist. At least two factors contribute to this. The first is the lack of correspondence between syphon and bucket volumes, such that more than one syphon operation may be needed to fill one bucket. The second factor is the continued inflow to the syphon during its emptying cycle. This lengthens the time required for the syphon to cycle, as well as worsening any mismatch between the amount of water discharged through the syphon to the tipping-bucket mechanism and the bucket capacity. In fact, there can be no fixed relationship between the syphon discharge volume and the capacity of a TBRG bucket. Therefore, one syphon emptying cycle can deliver more than the nominal 0.2 mm needed to trigger a tip event, such that the varying excess (dependent on the rainfall intensity) drains to the second bucket, which in turn tips earlier than would be expected. Consequently, even at constant intensity, the ITTs display increased variability, with widely-varying apparent intensities among successive ITTs. The variance among ITTs is shown always to be greater in data from a syphon-equipped TBRG than from a "straight-through" (no-syphon) gauge, such that the reliability of intensity data obtained from the ITTs of a syphon-equipped TBRG are reduced by the presence of the syphon. [ABSTRACT FROM AUTHOR]

To ensure that the hexagonal bucket foundation (HBF) for offshore wind turbines (OWTs) can be immersed and landed safely at different installation water depths, an experimental study with a 1:60 scale model was conducted to investigate the motion characteristics of the HBF during the immersion process. Self-stability tests, free decay tests, and motion response tests in regular waves were performed. Then, a numerical immersion model of the HBF considering different gas ratios is proposed and verified by comparing with experimental results, indicating that the accuracy of the numerical method improves as the gas ratio decreases. The synthesized experimental and numerical results show that the stability of the HBF decreases significantly at the immersion depth up to 17.7 m. Moreover, for a broader application of the HBF in transitional water (the water depths of 20–50 m), a novel immersion technology utilizing a combined system of hoisting and mooring (CSHM) is proposed. A numerical HBF-CSHM coupling immersion model is established to investigate the feasibility of this proposed method, focusing on effects of different wave conditions and the layout of the CSHM on the motion responses of the HBF at different immersion depths. The results show that the CSHM is feasible and effective in reducing the response amplitude of the HBF for both vertical and rocking motions at the sudden change in the area of waterplanes, compared with the conventional hoisting method. The rotational and translational responses patterns of the HBF with the wave period are different. In addition, the HBF tends to suffer from higher motion responses in State II and state III during the whole immersion process, which can be effectively reduced by setting the initial angle of the mooring wires to the vertical to 20°. • Experimental and numerical study on motion characteristics of the HBF during the immersion process were performed. • A novel immersion technology utilizing a combined system of hoisting and mooring was proposed for transitional water. • Motion responses of the immersion system for bucket foundation in waves was research. • Determine the risk status of the HBF during the immersion process in transitional waters. [ABSTRACT FROM AUTHOR]

The soil surrounding bucket foundations that are subjected to vertical cyclic loading would become softened but not consolidated. This would reduce the uplift resistance and even cause foundation failure. The paper firstly investigates the development, especially the dissipation of excess pore pressure and base suction (the suction between the bucket lid and soil) under vertical cyclic loading through 1 g model tests. The test results demonstrate that although base suction can bear 54 % of the uplift resistance of the bucket foundation at the beginning, the upward movement of foundation causes cracks at the soil surface, which accelerates excess pore pressure dissipation and leads to faster foundation failure. Therefore, the base suction should not be considered in the foundation design under long-term cyclic uplift loading. Then, an amended kinematic hardening model that can consider the strain softening effect of soil is employed to obtain the uplift resistance under vertical monotonic and cyclic loadings for various soil softening parameters and cyclic load level (the ratio of cyclic mean load to the monotonic ultimate uplift resistance). Through extensive fatigue analyzes with tens of thousands or even hundreds of thousands of cyclic loadings in each analysis, it is concluded that the fatigue cyclic number increases as the cyclic load level decreases or softening parameters (ξ 95 and δ rem) increase. A prediction formula of fatigue curve of bucket foundation is proposed and verified to predict the fatigue cyclic number. The prediction error is within 10 %, and the formula can provide a convenient reference for the design of bucket foundation. [ABSTRACT FROM AUTHOR]

Traditional suction bucket foundations incur high maintenance costs and are susceptible to corrosion, resulting in a diminished bearing capacity over prolonged service. The suction bucket foundation, constructed with a glass fibre-reinforced polymer (GFRP), introduces a novel approach to iteratively optimise conventional steel bucket foundations. In this study, three-dimensional finite element models of the GFRP bucket-soil interaction were established using the VUMAT subroutine, which incorporates the stress-strain damage relationship of GFRP materials. The mechanical response during installation was analyzed for different fibre-laying angles(A) and wall thicknesses(t) of the GFRP bucket, and the results were compared with those of a steel bucket. The results indicated increased circumferential stress, radial deformation, and out-of-roundness of the GFRP bucket as the fibre laying angle increased. Deformation and stress of the bucket skirt remained low at A of 0–45°. When A ≥ 60°, the matrix's damage area significantly increases, with the minimum damage occurring at 45°. For A ≤ 30°, it approaches the maximum radial deformation of an equivalent-sized steel suction bucket. As the wall thickness increased, the circumferential stress, radial deformation, and out-of-roundness of the GFRP bucket skirt gradually decreased. When the GFRP bucket t was four times that of the steel bucket, its radial deformation was approximately equal. • Provide new reference for the renewal and replacement of traditional suction buckets. • Critical control parameters for the response of GFRP suction bucket were determined. • GFRP material subroutine was written and applied. • Parameter coupling effect of GFRP suction bucket was considered and determined. [ABSTRACT FROM AUTHOR]

The suction bucket jacket foundation has become a widely choice for supporting offshore wind turbines. Assessing the installation of the suction bucket foundation (SBF) is important as it significantly affects the stability of the offshore wind system and the overall project cost. Currently, experience with suction bucket jacket foundation installations primarily revolves around stiff clay and dense sand, drawing insights from North Sea projects (e.g. the design method reported by DNV-RP-C212). However, there is a shortage of publicly available knowledge concerning SBF installations in the South China Sea, characterised by deep-covered mud (i.e. very soft clay) and extensive layered soils. Existing design parameters may not adequately address these challenges, highlighting the need for a site-specific installation design method. This study introduces a tailored approach for evaluating design parameters of the SBF installation in the seabed conditions of the South China Sea. Utilising field data from 19 suction bucket jacket installations across the region, the proposed method undergoes rigorous validation and testing. The findings of this study aim to contribute to the advancement of offshore SBF installations in the intricate geological setting of the South China Sea. By presenting the SBF installation design method, the research offers practical guidance for both the evaluation of suction bucket jacket foundation installations and the optimisation of turbine locations in the region. • Unique field installation data and Methodology: Study on SBF installations in South China Sea introduces new evaluation method, adapted to the unique seabed conditions of the region, validated with 19 regional installations. • Two-Phase Installation Process and Challenges: The paper outlines SBF installation phases: self-weight, suction penetration. Emphasizes accurate suction pressure assessment for proper installation, avoiding issues. • Proposed New Evaluation Method: A novel CPT-based approach classifies design parameters using normalised velocity and drainage conditions, enhancing accuracy for South China Sea seabed. [ABSTRACT FROM AUTHOR]

This study investigates the behavior of suction bucket foundations during seismic loading induced soil liquefaction through shaking table experiments using both steel and 3D printed mini buckets. The pore water pressure response of the soil inside and around the mini buckets was monitored, and the results show that excess pore water pressure ratios greater than 1.0, indicating liquefaction occurred inside and around the buckets. In order to verify whether the soil plug liquefies under seismic loading, a floating ball experiments was specifically designed. The findings suggest that behavior of suction bucket foundations may differ from that of gravity-based foundations when experiencing soil liquefaction, owing to their unique semi-enclosed geometric structure and suction installation method. The appropriately weighted steel mini bucket has the advantage of being less prone settlement in the liquefied soil, making it suitable as a monitoring platform for soil liquefaction. • This study investigates the behavior of suction bucket foundations during seismic loading induced soil liquefaction through shaking table experiments using both steel and 3D printed mini buckets. • According to the response of suction bucket foundations under seismic load, the suction bucket foundations exhibit unique behavior compared to gravity-based foundations when experiencing soil liquefaction. • The pore water pressure response monitored inside and around the mini buckets, as well as the floating balls inside the buckets, could both verify that liquefaction occurred entirely under seismic loading. • The research offers a novel approach to monitoring excess pore water pressure response of soil during seismic shaking, enhancing the understanding of soil liquefaction processes. [ABSTRACT FROM AUTHOR]

Natural frequencies and foundation displacements are vital for the safe operation of offshore wind turbines because of their dependence on the equivalent stiffness of foundations. To investigate this dependency, a finite element method based on substructures is proposed for wide and shallow bucket foundations (aspect ratios of 0.25–1). The equivalent stiffness coefficient (k i) is defined to analyze the influences of the relative skirt flexibility, foundation size, and soil parameters on the equivalent stiffness. The results highlight the predominant impacts of the relative skirt flexibility and aspect ratio on the equivalent stiffness coefficients of bucket foundations. Conversely, certain factors, such as bucket diameter, skirt thickness, and soil modulus, have minimal influences on the equivalent stiffness coefficients. The significance of the Poisson's ratio of the soil is particularly notable, especially concerning the vertical stiffness coefficients. Based on finite element calculations, an empirical formula for bucket foundation equivalent stiffness is proposed and effectively utilized for predicting natural frequencies and evaluating foundation displacements. • A method of calculating equivalent stiffness based on the substructure is proposed. • Relative skirt flexibility and aspect ratio emerge as the primary influencing factors. • Bucket diameter, skirt thickness, and soil modulus have minimal influences on equivalent stiffness coefficients. • The significance of the Poisson's ratio of the soil is notable. • An empirical formula for equivalent stiffness calculation is proposed. [ABSTRACT FROM AUTHOR]

Large-diameter monopiles have been widely used for constructing offshore wind turbines. The bearing capacity of a monopile foundation is a significant research problem. In this study, a new type of foundation, known as the pile–bucket foundation, was investigated to improve the bearing capacity of monopiles. A finite element software was used for establishing several numerical models of monopile and pile–bucket foundations to analyze the reinforcement afforded by the bucket attached to the monopile foundation. Furthermore, considering that offshore wind turbines are prone to resonance under the excitation of wind and wave loads, the natural frequencies of the monopile and pile–bucket foundations were determined and compared using both analytical and numerical methods. The results show that compared to the monopile foundation, the pile–bucket foundation has a significantly higher bearing capacity, mainly for large bucket diameters. The natural frequencies of the pile–bucket foundations are slightly higher than those of the monopile foundations. The addition of the bucket can effectively improve the natural frequency without changing the diameter of the monopile and thus saving the foundation cost. [ABSTRACT FROM AUTHOR]

Identification of the basic parameters of static stability (BPSS) of the slewing superstructure is the key step in solving the problem of its static stability, as well as static stability of the entire bucket wheel excavator (BWE). Specificity of the slewing superstructure examined in this paper lies in the kinematic breakdown system (KBS) which prevents the loss of static stability on the counterweight side. Development of a unique method for the formation and two-step validation of the calculation models for this particular design concept was the main objective of the presented research. A two-step validation of the analytical models is conducted based on the experimental results. As the outcome, the final calculation model formed in such manner represents an accurate basis both for the proof of static stability and for the monitoring of the BPSS during exploitation. By comparing the results of the control weighing and the referent values of the final calculation model it was concluded that the existing double-walled bucket wheel represents a 'weak point' of the considered BWE. [ABSTRACT FROM AUTHOR]

This study investigates the dynamic pressure at the flip buckets of chute spillways, which is one of the most important design parameters of these structures. First, the dimensionless parameters affecting pressure were determined by dimensional analysis. Following that, according to the characteristics of selected dams with chute spillways leading to flip buckets, certain Froude number intervals of inflow to the flip bucket, as well as the chute slope angle, radius, and flip bucket curvature angle were selected for analysis. The combination of these parameters resulted in a total of 137 models simulated in FLOW-3D to obtain bottom pressure and maximum pressure values in the flip bucket. Next, based on the dimensionless parameters considered, equations were proposed to determine the bottom pressure and maximum pressure in the flip bucket downstream of the chute, using multiple regression analysis. Using the numerical modeling run results, along with multiple regression analyses, the unknown coefficients of the dimensionless pressure relationship were determined, and final equations for the bottom pressure and maximum pressure were presented. The correlation coefficient and Mean Absolute Percentage Error (MAPE) values of the proposed equations for determining the bottom pressure and maximum pressure were 0.94 and 0.96, and, 6.75% and 8.49%, respectively. These values indicate the appropriate accuracy of the proposed equations. In the proposed equations, the Froude number, relative curvature, chute slope angle, takeoff angle, and flip bucket's curvature angle, respectively, had the highest impacts on the bottom pressure and maximum pressure. [ABSTRACT FROM AUTHOR]

Scour risk assessment considering reaction force at foundation was proposed and applied to newly developed pentapod suction bucket support structures for a 5.5 MW offshore wind turbine under ultimate limit state environmental load. Scour hazard was obtained according to scour depth by using an empirical formula, which is the function of marine environmental conditions such as significant wave height, significant period, and current velocity. Fragility of the pentapod support structure was evaluated using the bearing capacity limit state criterion under ultimate limit state load case. Scour risk was assessed by combining the scour hazard and the fragility. Finally, scour risk of the developed pentapod suction bucket support structure under ultimate limit state has been assessed. [ABSTRACT FROM AUTHOR]

Sand liquefaction under seismic load causes severe failure of bucket foundations for offshore wind turbines. This study conducted shaking table tests for two different types of bucket foundations: mono bucket foundation (MBF) and composite bucket foundation (CBF). Furthermore, five groups of EI-Centro seismic waves with different intensities were applied. The excess pore water pressure and acceleration of the foundation soil were measured. The influences of bucket foundations on the seismic behavior of sand were explored by comparing the excess pore water pressure and acceleration at different positions. Moreover, the seismic responses of two types of bucket foundations were compared, and the effects of bulkheads in CBF on the seismic performance of foundation soil were clarified. The test results show that the seismic response of the soil inside the bucket is clearly suppressed compared with the soil outside the bucket, and thus the risk of liquefaction is lower. Furthermore, the seismic response of the CBF is significantly weaker than that of the MBF, and the anti-liquefaction performance of the CBF soil foundation is better. This implies that CBFs are safer than MBFs during earthquakes. [ABSTRACT FROM AUTHOR]

Cellular Bucket Brigades (CBBs) can absorb the impact of velocity variability on throughput, which makes them perform better than traditional Bucket Brigades under random worker velocities. However, the throughput of CBBs may decrease because of blocking and/or halting at discrete workstations. Among the various solutions, collaboration has emerged as an interesting candidate because it can substantially reduce the impact of blocking and halting. To improve the throughput of the existing collaborative model, two types of collaboration models are proposed from different perspectives. One of the problems addressed is that the existing collaborative model performs unsatisfactorily to achieve higher throughput in some cases due to its design, and another is that it has complex worker operation principles and many unproductive movements. A comparison of the proposed and existing models shows that the proposed models achieve outstanding improvements in throughput figures. [ABSTRACT FROM AUTHOR]

To improve the bearing capacity of offshore wind turbine foundation, a pile-bucket composite foundation with bucket foundation and steel piles was designed. Based on the limit equilibrium method, the theoretical formula of horizontal bearing capacity of pile-bucket composite foundation was proposed with considering different pile numbers. The finite element analysis model was established to analyze the bearing capacity of pile-bucket composite foundation with different pile numbers, pile diameters and arrangements. The results show that the ultimate bearing capacity of pile-bucket composite foundation can be effectively improved for the same steel amounts of foundation. Compared with single bucket foundation, the bearing capacity of bucket foundation with 1 pile is increased by 44.27%, and the bearing capacity of bucket foundation with 3 piles is increased by 35.76%, while the bearing capacity of bucket foundation with 4 piles is increased by 34.73%. Obvious wedge-shaped equilibrium plastic strain is appeared in the soil foundation of the passive area. The more obvious the equilibrium plastic strain is, the higher the load sharing ratio of foundation soil is, and the higher the bearing capacity of foundation is. The high stress area of foundation is mainly concentrated in the top cover of foundation. [ABSTRACT FROM AUTHOR]

Purpose: In regions of the world where resources can limit medical care (limited-resource settings, LRS), most meniscal tears are often treated with meniscectomy. A simple, low-cost option for meniscal repair has been developed. We sought to evaluate patient reported outcomes (PROMs) and clinical failure rates of bucket handle meniscus tears (BHTs) treated with meniscal repair in a LRS. Methods: We prospectively enrolled patients over 18 who were treated for BHT with meniscal repair in a LRS. Meniscal repair was primarily accomplished using an outside-in technique. Pre-injury and final follow-up PROMs were recorded. Clinical failure was defined as the need for re-operation or symptoms that prevented the patient from returning to recreational activities or work responsibilities. Results: Nineteen patients with a mean age of 25.4 years were eligible. Two patients sustained a clinical failure (10.5%). At mean follow-up of 40.6 months, there was significant improvement in all PROMs from baseline. Subgroup analysis revealed no significant difference in the failure group compared to the success group in number of knots used, pre-injury Tegner score, number of devices used, suture type, or technique. Conclusion: Bucket-handle meniscal tears can be repaired using a low-cost technique resulting in satisfactory healing rates and excellent outcomes. [ABSTRACT FROM AUTHOR]

This study presents finite element analysis (FEA) results of suction buckets subjected to vertical sustained uplift loads, focusing on the suction pressure and the displacement responses. The accumulative seepage of water and the heave of the soil in the bucket are the key components of the displacement. The accumulative seepage of water is modelled using a layer of soft elastic material (water elements) beneath the bucket lid. The model is first used to investigate the suction pressure and the displacement responses under drained, partially drained, and undrained conditions. The components of the displacement are subsequently explained under different drained conditions. A critical uplift force is then defined when heave of the soil occurs. The influences of the key parameters on the displacement rates are analyzed. The fitting equations of the displacement rates with and without heave of the soil are presented, and the results calculated by equations are compared with those from available centrifuge tests and previous FEA. [ABSTRACT FROM AUTHOR]

Copyright of Lietuvos Archeologija is the property of Lithuanian Institute of History and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bucket brigades are notably used to coordinate workers in production systems. We study a J‐station, I‐worker bucket brigade system. The time duration for each worker to serve a job at a station is exponentially distributed with a rate that depends on the station's expected work content and the worker's work speed. Our goal is to maximize the system's productivity or to minimize its inter‐completion time variability. We analytically derive the throughput and the coefficient of variation (CV) of the inter‐completion time. We study the system under two cases. (i) If the work speeds depend only on the workers, the throughput gap between the stochastic and the deterministic systems can be up to 47% when the number of stations is small. Either maximizing the throughput or minimizing the CV of the inter‐completion time, the slowest‐to‐fastest worker sequence always outperforms the reverse sequence for the stochastic bucket brigade. To maximize the throughput, more work content should be assigned to the stations near the faster workers. In contrast, to minimize the CV of the inter‐completion time, more work content should be allocated to the stations near the slower workers. (ii) If the work speeds depend on the workers and the stations such that the workers may not dominate each other at every station, the asymptotic throughput can be expressed as a function of the average work speeds and the asymptotic expected blocked times of the workers, and can be interpreted as the sum of the effective production rates of all the workers. [ABSTRACT FROM AUTHOR]

• We show that BucketSort runs in linear time with very high probability when the keys are chosen independently and uniformly at random from an interval. • The exponent in the probability depends on which subroutine is used to sort the elements in each bucket. Bucket Sort is known to run in expected linear time when the input keys are distributed independently and uniformly at random in the interval [ 0 , 1). The analysis holds even when a quadratic time algorithm is used to sort the keys in each bucket. We show how to obtain linear time guarantees on the running time of Bucket Sort that hold with very high probability. Specifically, we investigate the asymptotic behavior of the exponent in the upper tail probability of the running time of Bucket Sort. We consider large additive deviations from the expectation, of the form cn for large enough (constant) c , where n is the number of keys that are sorted. Our analysis shows a profound difference between variants of Bucket Sort that use a quadratic time algorithm within each bucket and variants that use a Θ (b log ⁡ b) time algorithm for sorting b keys in a bucket. When a quadratic time algorithm is used to sort the keys in a bucket, the probability that Bucket Sort takes cn more time than expected is exponential in Θ (n log ⁡ n). When a Θ (b log ⁡ b) algorithm is used to sort the keys in a bucket, the exponent becomes Θ (n). We prove this latter theorem by showing an upper bound on the tail of a random variable defined on tries, a result which we believe is of independent interest. This result also enables us to analyze the upper tail probability of a well-studied trie parameter, the external path length, and show that the probability that it deviates from its expected value by an additive factor of cn is exponentially small in Θ (n). [ABSTRACT FROM AUTHOR]

The bucket foundation is a new type foundation which is suitable for offshore wind turbines. The failure envelope is used to check the bearing capacity under combined loading conditions, especially for foundations with irregular shapes. Due to the coupling effect between horizontal and moment loads, the H-M failure envelope has an obvious asymmetry, which makes the established algebraic equation of the envelope form complex and inconvenient to apply. In this paper, an optimised failure envelope is proposed to reduce the coupling degree between horizontal and moment loads by moving the load reference point to the rotation centre of bucket foundation. Furthermore, the algebraic equation of the failure envelope is established based on the optimised envelope by using the depth of the bucket foundation rotation centre. The equation has fewer parameters and clearer physical meanings than the conventional one, which is convenient for engineering applications. [ABSTRACT FROM AUTHOR]

Bucket fill factor is of paramount importance in measuring the productivity of construction vehicles, which is the percentage of materials loaded in the bucket within one scooping. Additionally, the locational information of the bucket is also indispensable for scooping trajectory planning. Some research has been conducted to measure it via state‐of‐the‐art computer vision approaches, but their robustness against various environment conditions is not considered. The aim of this study is to fill this gap and six distinctive environment settings are included. Images captured by a stereo camera are used to generate point clouds before being structured into 3D maps. This novel preprocessing pipeline for deep learning is originally proposed and its feasibility has been validated through this study. Moreover, multitask learning is employed to exploit the positive relationship among two tasks: fill factor prediction and bucket detection. Therefore, after preprocessing, 3D maps are forwarded to a faster region with convolutional neural network incorporated with an improved residual neural network. The value of fill factor is acquired via a classification and probabilistic–based approach, which is novel, achieving an inspiring result (overall volume estimation accuracy: 95.23% and detection precision: 92.62%) at the same time. [ABSTRACT FROM AUTHOR]

A tipping bucket is an accurate and reliable device that is used to measure runoff water flows, especially in small-scale catchments. However, the performance of the tipping bucket device depends on the magnitude of the runoff water flow, the dimensions of the tipping bucket and the accuracy of the calibration. This paper discusses technical guidelines that govern the design, construction, field installation, calibration and error minimisation of tipping bucket gauges used for runoff estimation in small-scale catchments under agricultural land-use systems. The proposed tipping bucket system is a cost-effective and simple device that can be fabricated in a basic mechanical workshop. The device proved to be a sensitive and reliable instrument on which accurate measurements can be read out easily with minimal maintenance. [ABSTRACT FROM AUTHOR]

The paper deals with the analysis of the dynamic response over time of the excavator boom during operation. For a start, we determined the variation in time of the forces acting on the rotor shaft, due to the excavation. These forces have high values and a slow variation over time, which depends on the rotation speed of the bucket wheel and the number of buckets installed on it. A virtual model of the BWE boom was proposed, for which the dynamic response in time due to the excavation forces was determined, for a point in the main cabin of the BWE. A virtual sensor has been attached to this point corresponding to seat of the operator. The simulation of the dynamic response over time was performed taking into account a global damping of 2% of the critical damping. The simulation was performed both for the excavation of a homogeneous material and for the case of a shock (a sudden appearance of an inclusion of hard material during the cutting of the homogeneous material). [ABSTRACT FROM AUTHOR]

This paper briefly outlines the design of replaceable cutting teeth of bucket chain excavator, which are attached to a holder with a detachable joint. The description of the rock cutting process is very complex, so the investigation of the effect of lateral forces is complicated through cutting tests. We use accordingly numerical analysis to examine some segments of the cutting process. Our main objective is to present the finite element analysis of cutting teeth in which the linear increase of the lateral force is taken into consideration. The finite element analysis is a powerful technique, which is enabled to compute the stress and displacement distribution in cutting teeth. The simulation results have shown that the maximum stresses decrease if the lateral force increases. The geometry of the optimized cutting teeth will be safe under the given loading conditions. [ABSTRACT FROM AUTHOR]

The southeastern Carpathian peat bogs are a widespread habitat in the subalpine floor of the Făgăraș Mountains. They are found in the area of glacial lakes and on valleys and slopes near the streams. On the smooth plateau with excess moisture of the Valea Rea there is a peat bog on an area of about 1 ha. Located at the base of the Viștea Mare and Moldoveanu peaks, the Valea Rea Bucket, modulated by glaciers that dug into the rock of the mountain, sheltered a plateau on which the place of gravel is taken by a swamp area with the appearance of a small delta, with an area of about one kilometer square and several small lakes and islands of vegetation. On the left, the Valea Rea Bucket is guarded by the Galbena Mountain and Roșu Peak (2465 m), on the right by the Valea Rea Edge and in front by the Viştea Mare (2527 m) and Moldoveanu (2544) massive, Moldoveanu being the highest peak in the country. Under the Moldoveanu peak there is a large lake, the Triangular Lake of Moldoveanu, which received this name due to its shape. Located at 2159 m altitude, it is located at the top of the glacial bucket and is fed by underground springs. From the Triangular Lake of Moldoveanu (Iezerul Moldoveanu) the water flows through the Budurile Văii Rele, in the most spectacular waterfalls in this area, to the Valea Rea stream, the main tributary of the Doamnei River. [ABSTRACT FROM AUTHOR]

This paper proposes a prediction model for three-dimensional spatio-temporal soil deformation in bucket excavation. The prediction model for soil deformation (PMSD) consists of two machine learning processes: the long short-term memory (LSTM) and convolutional autoencoder (Conv-AE). These processes use datasets obtained from an experimental apparatus for bucket excavation developed in this work. The apparatus equips multiple depth cameras that precisely capture time-series data of soil deformation in bucket excavation. The LSTM, an extension of a recurrent neural network, successively predicts three-dimensional soil deformation. The Conv-AE is incorporated to both ends of the LSTM in order to quasi-reversibly compress and reconstruct the datasets so that the computational burden of the LSTM is relaxed. Qualitative and quantitative evaluations of the PMSD confirm the feasibility of time-series prediction of three-dimensional soil deformation. The Conv-AE shows sufficient accuracy equivalent to the measurement accuracy of the depth camera. The prediction accuracy of the PMSD is about 10 mm in most of the cases. [ABSTRACT FROM AUTHOR]