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In Australian domestic structures, steel framing and sheathing panels are usually connected using screws. The ceiling diaphragm plays an important role in distributing lateral loads to the bracing walls. Shear connection tests could be used to observe the ceiling diaphragm performance without the complexity of testing full-scale isolated diaphragms. In this research, numerous inexpensive tests have been conducted to replicate representative tests to determine the parameters outlining the load-displacement behaviour for the screw connections between cold-formed steel framing members and plasterboard sheathing. All investigations of shear connection tests have focused on monotonic loading testing. These tests are aimed to determine the lower and upper bounds of the load-displacement curves for typical cold-formed steel framing-to-plasterboard screw connections in ceiling diaphragms. Finally, finite element (FE) models were developed by utilising these test results and predicted the performance of full-sized plasterboard-clad cold-formed steel framed ceiling diaphragms under lateral loading. [ABSTRACT FROM AUTHOR]

Fully grouted reinforced masonry (FGRM) walls, being an assemblage of hollow blocks with all cores grouted and vertical and horizontal reinforcements, offer unparalleled resistance to lateral and gravitational loading over their unreinforced counterparts. The Australian masonry standard AS 3700:2018 provides guidelines for the design of reinforced masonry walls to seismic or cyclonic loading with a minimum vertical and horizontal reinforcement ratio as low as 0.13% and 0.07%, respectively. The performance of FGRM shear walls in a building structure designed within the AS 3700:2018 provisions with a low reinforcement ratio has hardly been addressed by researchers. This paper investigates the structural performance of a three-story prototype FGRM building under quasi-static lateral loading applied severally from different directions. The assessment is carried out exclusively using an explicit finite element (EFE) model. The EFE model is briefly presented and the structural performance--that is, load capacity, stiffness, and displacement ductility--of the FGRM building and the component walls are discussed in detail. The structural performance of the walls of the prototype building is compared with similar walls (which were analyzed separately), and this comparison provides key insights on the influence of realistic end support conditions on the structural behavior of FGRM walls. It was found that the component walls of the prototype FGRM building experienced pure in-plane and out-of-plane loading, and their loaddisplacement relationship and failure pattern altered due to changes in the loading direction. [ABSTRACT FROM AUTHOR]

Granular columns are widely used to enhance the bearing capacity of weak soil. The filling material of columns is generally stone, gravel or sand. The use of industrial wastes such as steel slag in civil engineering applications not only reduces environmental pollution, but also leads to cost benefits. So far, many studies have been done on the behaviour of granular columns with and without geosynthetic encasement under vertical loads; however, very limited studies were conducted on the behaviour of waste granular columns with and without geosynthetic encasement under lateral loads. Therefore, this study aims to evaluate the lateral load capacity of steel slag granular columns reinforced with geosynthetic using a large direct shear test apparatus. Results demonstrated that the use of steel slag column improved the lateral load capacity of soil. The use of geosynthetic encasement in floating steel slag column could significantly enhance both the peak and critical state shear strength. The results indicated the viability of using steel slag column as a soil reinforcement providing sustainable and technical benefits mainly when using geosynthetic reinforcement. [ABSTRACT FROM AUTHOR]

Open caisson is a typical gravity-type anchorage for suspension bridge, especially when soft soils are encountered. It is necessary to study the time effect of open caisson subjected to long-term lateral loading, since consolidation occurs in soft soils that can change the behaviour. A model-scale experimental program was initiated on open caisson foundations under combined lateral incremental loading and sustained loading. The development of earth pressure, caisson displacement and tilt, and soil displacement was recorded. Three-dimensional finite element analysis was further conducted to facilitate thorough understanding of long-term behaviour of caisson foundation. It is found that both passive and active zones were formed at the caisson front, showing an inflection point at a depth of 2/3 times the embedment depth. Laterally, a deforming caisson can influence a limited range up to 1.5 times the caisson width. Upon sustained loading, the responses of both caisson and soil became stabilized at a later stage of consolidation, which were much higher (more than two times) compared to those at an early stage of consolidation. It is recommended that analysis of open caisson should consider the effect of sustained loading to avoid unsafe design. • Model test and numerical simulation were conducted on open caisson under long-term lateral loading. • Inflection occurred at a depth of 2/3 times the embedment depth of open caisson. • Laterally deforming caisson influenced a limited range up to 1.5 times the caisson width. • Upon sustained loading, much higher responses of caisson and soil stabilized at a later consolidation stage. • Analysis of open caisson should consider the effect of sustained loading to avoid unsafe design. [ABSTRACT FROM AUTHOR]

Previous studies have not extensively explored the collective impact of lateral, axial, and thermal loading on the ultimate vertical bearing capacity of energy piles, q u. This study investigates q u values for energy piles in dry sandy and clayey soils under varying lateral loads and temperature conditions using numerical and analytical solutions, considering temperature-dependent variables. The numerical results were validated against experimental data. The analytical solution aligns well with numerical analyses, though it yields slightly higher q u values in sandy soil. Both numerical and analytical solutions show that cooling and heating can respectively increase and decrease q u under corresponding conditions. Numerical simulations indicate that in clay, lateral load enhances q u , with increases ranging from 8 % to 20 % across different thermomechanical conditions. In sand, the effect of lateral load depends on thermal conditions, increasing by 2 %–5 % during cooling and decreasing by 3 %–5 % during heating. The analytical solution showed that increasing lateral load would increase q u in sand by 0.5 %–2 % and in clay by 1 %–5 %, with a more significant increase in clay. Analytical and numerical parametric studies also revealed the higher influence of soil cohesion and pile diameter on q u values under different thermomechanical conditions. [Display omitted] • Axial ultimate bearing capacity of energy piles under lateral loads is studied. • Different thermomechanical conditions, lateral loads and soil types are considered. • Numerical modeling, analytical assessments and parametric studies are conducted. • Numerical modeling and analytical solution are verified using experimental data. • Results from analytical and numerical methods are compared and discussed. [ABSTRACT FROM AUTHOR]

The caisson foundation has evolved into a suitable alternative foundation for offshore structures, specifically for offshore wind turbines (OWT). The OWT caisson foundations are exposed to a combination of lateral, vertical, and overturning moments. A precise assessment of horizontal load response is necessary to ensure the normal functioning of these foundations for a proper design. This paper presents the results of three-dimensional finite element analyses of the lateral load-bearing behavior of the caisson foundation used for offshore wind turbines. The numerical model was validated and cross-checked by experimental data from the literature. The caisson's behavior and the soil response supporting the caisson foundation subjected to static horizontal loads were examined. The effect of the slenderness of the caisson foundation was examined by changing the diameter and the depth of the caisson. It was observed that the depth of a caisson has a more profound effect on the lateral load-bearing capacity of the foundation. The caisson's rotation center or inflection point was found to be at a distance of approximately 0.8 times the caisson depth, and it shifted downward with the increase in caisson diameter. Soil upheaval in the loading direction was observed as a precursor to the pullout failure, which increased with loading eccentricity and decreased with the caisson depth. • The effect of aspect ratio and the pullout behavior of caisson were analyzed. • The inflection point of rotation of caisson and soil heave around it were analyzed. • Parametric studies were conducted on the caisson's thickness, diameter, and depth. • Parametric studies were also conducted on load eccentricity and caisson lid diameter. [ABSTRACT FROM AUTHOR]

This article presents the results of complex theoretical and experimental studies on creating universal continuous earthmoving machinery operating under non-standard loading conditions, namely, cyclic lateral loading on the actuator during digging. The lateral loading is due to the complex nature of the actuator motion when digging the soil, namely, the longitudinal motion of the machinery, the actuator digging the soil, and the lateral reciprocating motion of the actuator. This allows for variable width excavations in the soil, whose width exceeds the width of the actuator. The key issue of this machinery operation is to provide its course stability. The article considers the choice of soil-developing actuator and shows the developed calculation schemes of external loading on the operating equipment and a base tractor when digging long excavations in the soil. The dependencies to define external forces acting on the actuator when digging the soil and determining the machinery course stability, considering their spatial nature, have been developed and suggested for practical use. The conditions to ensure the stability of the course of universal earthmoving machinery have been formulated and substantiated. The developed method for determining course stability can be used when creating industrial samples of trenching earthmoving machinery. [ABSTRACT FROM AUTHOR]

Pile foundations are often subjected to lateral loadings. By adding steel plates (fins) to the side of the pile, steel fin pile foundations (SFPFs) can improve the lateral load capacity of piles. Existing numerical studies using elastic–perfectly plastic models (e.g., Mohr–Coulomb model) for soil behavior may result in unrealistic load response when modeling soil–pile interaction in dense sand due to the lack of consideration of strain-hardening/softening behavior. In the present study, finite-element analyses were conducted to understand the effect of fin geometry on the lateral load capacity of SFPFs. The prepeak hardening and postpeak softening soil behavior was accounted for by varying soil strength parameters with plastic shear strain based on a modified Mohr–Coulomb model. The developed model was calibrated and validated against well-documented experimental and field tests in the literature. The validated model was subsequently used to conduct a parametric study to understand the effect of fin geometry on the response of SFPFs subjected to lateral loading at the pile head. The behavior of SFPFs at different displacement levels and load levels was studied. The effect of the relative density of soil on the performance of SFPFs was also investigated. Based on the numerical simulation results, the optimal fin width and length values for mobilizing soil resistance were suggested and the underlining mechanisms affecting the efficiency of fins were discussed. [ABSTRACT FROM AUTHOR]

The Dynamic Penetration Test (DPT) is one of the simplest and least expensive in-situ tests, used in geotechnical projects. However, in the literature, there is no available practical method for constructing the P–Y curves based on the DPT test (P is the soil-pile reaction and Y is the pile deflection). This paper is aimed at suggesting a new practical method of constructing the P–Y curves on the basis on the DPT data in sandy soils. This method was derived from the interpretation of five full-scale lateral loading tests on fully instrumented piles in sandy soils. Simple analytical formulation of the P–Y curves parameters, as well as design practical charts were proposed as function of the number of blows Nd of the DPT test. The results predicted by the proposed DPT based P–Y curve agreed relatively well with measured results within the margin of small to medium deflection. [ABSTRACT FROM AUTHOR]

Piles subjected to lateral loads also sustain axial loads, which may influence the flexural property of pile sections. To simulate the effects of axial loading on the pile section in nonlinear pushover analysis, this paper presents a pile model that reflects the distribution of flexural rigidity on the basis of initial axial forces in the pile and the change in plastic hinge properties due to varying axial forces. Based on the moment-curvature curves of pile sections at various axial forces obtained from section analyses, both an effective flexural rigidity-axial force relationship and the axial force dependent plastic hinge properties, including the axial force-effective yield moment interaction curve and normalized moment-plastic curvature curves, are constructed for the model. This model is used to simulate pile load tests in the literature, and reasonable predictions are obtained. Parametric analyses are conducted to examine model performance and the influence of varying axial loads on pile response. The conventional method that considers a constant axial load overestimates the lateral stiffness and strength during compression but underestimates those during tension for a single-pile condition. Regarding a group-pile condition, our proposed model can discern the difference in moment profiles and the development of plastic hinges between the front and back piles. [ABSTRACT FROM AUTHOR]

The energy absorption behavior of nested tubes under lateral loading conditions was investigated in this study. Nested tubes are considered as an alternative to energy absorption structures used in many industries including automotive, military, and aerospace. Steel tubes with the same wall thickness and different diameters were used in the experiments. First, experiments of single tubes were carried out, and the deformation behavior of tubes under lateral load was examined in detail. Afterward, experiments were carried out on nested tube samples in which a minimum of 2 and a maximum of 6 tubes were used together in different numbers and sequences. It was seen from the experiments that the best-nested tube configuration in terms of energy absorption capacity was the sample that contains 6 tubes with 1767 J. While this sample absorbed 5% higher energy than the sample with 5 tubes, the specific energy absorption value was calculated to be 10% lower. Additionally, the sample with 6 tubes has a value of 43% in terms of energy efficiency which is 7% lower compared to that of the sample with 5 tubes. It was determined that the sample with 5 tubes yielded the most efficient design when specific energy absorption capability, work effectiveness, and energy efficiency parameters were considered.

Origami structures, which were inspired by traditional paper folding arts, have been applied for engineering problems for the last two decades. Origami-based thin-wall tubes have been extensively investigated under axial loadings. However, less has been done with radial stiffness as one of the critical mechanical properties of a tubular structure working under lateral loadings. In this study, the radial stiffness of novel thin-wall tubular structures based on origami patterns have been studied with compression tests and finite element analysis (FEA) simulations. The results show that the radial stiffness of an origami-inspired tube can achieve about 27.1 times that of a circular tube with the same circumcircle diameter (100 mm), height (60 mm), and wall thickness (2 mm). Yoshimura, Kresling, and modified Yoshimura patterns are selected as the basic frames, upon which the influences of different design parameters are tested and discussed. Given that the weight can vary due to different designs, the stiffness-to-weight ratio is also calculated. The origami-inspired tubular structures with superior stiffness performances are obtained and can be extended to crashworthy structures, functional structures, and stiffness enhancement with low structural weight. [ABSTRACT FROM AUTHOR]

Oil spillage occurrences are due to wars, accidents, drilling, storage, natural disasters, and rapid industrialization, which lead to huge amounts of waste discharge into adjacent areas. Soil contamination is also detrimental to associated structures and foundations. Therefore, in this research, experimental and numerical studies on laterally loaded piles near an oil-contaminated sand slope were conducted to estimate the ultimate lateral capacity, lateral displacement, and maximum bending moment of a single pile embedded in contaminated and uncontaminated sand slope. To simulate the contamination content as in field conditions, preparation of oil-contaminated layers of sandy soil was performed by blending clean sand samples with heavy motor oil at proportions of 0–6% of the dried weight of soil. These studies were performed by varying the contaminated sand layer thickness (LC), oil content (O.C), pile slenderness ratio (LP/DP) and distance from the slope crest (X) to the pile head. The results demonstrated a considerable reduction in the friction angle (Ø) with increasing oil content. Therefore, the ultimate horizontal load (Hu) of the pile also reduced. Moreover, the raise in the thickness of oil-contaminated sandy soil layer (LC) has resulted in an increment in the lateral movement of the pile (y) and a reduction in the ultimate horizontal load (Hu). When the proportion of the oil content increased to 2% over that in clean sand, the maximum bending moment raised by about 11%. In addition, a good consistency between the numerical analysis and experimental tests was observed.

The aim of this study was to evaluate the effect of off-axis implant placement in relation to the prosthetic crown on abutment screw loosening under different directions of twisting moments. Materials and Methods: Twenty-one implant assemblies were divided equally into three groups (n = 7). Each assembly consisted of an internal-octagon implant measuring 4.1 × 12 mm (standard plus implants) with corresponding 5.5-mm synocta abutments (Straumann) mounted in an epoxy resin-glass fiber composite. Group A had a straight implant configuration in relation to the prosthetic crown and was subjected to clockwise twisting moment (control). The other two groups, B and C, with off-axis implant placement were subjected to clockwise and counterclockwise moments, respectively. A lateral load of 80 N was applied to the specimens for 1 × 106 cycles at 90 degrees to the long axis of the implant. The loading point was 4 mm from the center of the implant in group A and 6 mm in groups B and C. The reverse torque value (RTV) of the abutment screw was measured before and after loading. Data were analyzed using a paired samples t test and one-way analysis of variance (ANOVA) at a significance level of a = .05. Results: An increase in postloading RTV was found relative to preloading RTV in all groups, but was only significant in group A (P < .05). The mean reverse torque difference (RTD) was higher in group A (3.17 ± 1.04 Ncm), followed by groups B (1.03 ± 1.41 Ncm) and C (0.43 ± 1.09 Ncm). A significant difference in RTD was noted between group A and the remaining groups (P < .05). However, no significant difference was found between groups B and C (P > .05). Conclusion: Placement of an implant in an off-axis relation to the prosthetic crown resulted in significantly lower reverse torque values compared with straight implant configuration. However, the extent of reduction in Ncm is small and is considered clinically insignificant in the studied implant system. Furthermore, no significant difference was found in RTV between clockwise and counterclockwise twisting moments. [ABSTRACT FROM AUTHOR]

The space elevator system is a space tether system used to solve low-cost space transportation. Its high efficiency, large load, reusability and other characteristics have broad application prospects in the aerospace field. Most of the existing mechanical models are based on "chain-bar" and a lumped mass tether model, which cannot effectively reflect the flexible behaviour of the rope of space elevator system. To establish an accurate mechanical model, the gradient deficient beam elements of the absolute nodal coordinate formulation (ANCF) are used to build the mechanical model of the space elevator system. The universal gravitation and centrifugal force in the model are derived. The calculation results of the ANCF model are compared with the results of the finite element method (FEM) and lumped mass (LM) models. The results show that the calculation results of the ANCF method are not very different from the results of the FEM and LM models in the case of axial loading. In the case of lateral loading, the calculation results of the ANCF method are basically the same as the results of the FEM and LM models, but can better reflect the local flexible deformation of the space elevator rope, and have a better calculation stability than FEM. Under the same calculation accuracy, the ANCF method can use fewer elements, and the speed of convergence is faster than the FEM and LM models. [ABSTRACT FROM AUTHOR]

In this paper, the flexural strength and buckling of the partially concrete-filled steel tubes (PCFST) under laterally repeated loads was investigated through three-point bending test configuration. Three-dimensional Finite Element (FE) models of the bending tests of the PCFST were developed, in which the concrete filling was modelled using elastic-plastic-fracture model capturing crack development and the tube steel was modelled using elastic-plasticity model. The bond between concrete and tube was considered as frictional touching contact. The validation showed the FE results including the ultimate flexural load and buckling failure mode of the steel tube were in excellent agreement with the experimental ones. A parametric study was then conducted using the verified FE models to investigate the effects of the tube diameter-to-thickness ratio, the concrete filling length ratio, the compressive strength of concrete, and the tube steel’s yield and tensile strengths on the PCFST’s ultimate flexural strength. Based on this study, buckling modes, the optimal concrete filling lengths, and the confined compressive strengths of concrete were determined considering the effects of all these parameters. The confined compressive stresses and strains in concrete predicted by the FE models were evaluated against those determined by theoretical models. The results revealed that the effects of concrete compressive strength to the PCFST’s flexural capacity was insignificant while increasing the tube diameter-to-thickness ratio or the tube steel’s yield and tensile strengths could significantly increase the PCFST’s flexural capacity and the confined compressive strength of concrete; and there was an optimal length of concrete filling at about 66% of the tube length. It demonstrated that the Finite Element analysis can therefore be used as a powerful method to the analysis and design the PCFST columns under lateral loads.

[Display omitted] • Conducting eight laterally loaded composite T-joint tests with different molding processes. • Applying network-free renormalization to characterize composite T-joints' cracking/failure. • Applying clustering algorithm to reveal composite T-joints' phase transition loads. • Verifying phase transition loads of composite T-joints from a renormalization perspective. Delamination or crack are standard failure patterns of composite T-joints. Most existing studies focus on pull-off loaded composite T-joint cracking but little focus on adverse conditions such as lateral loading. The mainstream composite T-joint research predicts the macroscale failure based on the composite's microscale/mesoscale crack starting and evolution. However, the cracking process is within the microscale, mesoscale, and macroscale, making detecting its starting based on phenomena complicated. This work attempts to directly model the macroscale deformation distribution from a thermodynamic perspective to reveal the cracking/failure evolution of a laterally loaded composite T-joint. Firstly, we conducted eight laterally loaded composite T-joint tests with different molding processes. Then, network-free renormalization was applied to construct Matrices (Modes) and Hamiltonians (Characteristic parameters) that can characterize their cracking evolution process. Further, a clustering algorithm was applied to reveal the cracking starting points (phase transition loads) embedded in the macroscale deformation distribution. We can verify its rationality by comparing the composite T-joints localized and systematic phase transition loads based on Wilson's phase transition theory. In summary, this work applies network-free renormalization and clustering algorithms from a thermodynamic perspective to reveal the cracking starting point embedded in the macroscale deformation distribution of the laterally loaded composite T-joints. [ABSTRACT FROM AUTHOR]

Modelling the soil-pile interaction using the Finite Element Method (FEM) might be a time-consuming process and required entirely specific soil properties. Moreover, most of the codes that have been developed for offshore wind turbines use one or more of some simplified linear foundation models suitable for dynamic analysis such as Apparent Fixity (AF) model. In the AF model for pile foundation systems, a fixity length level below the seabed is designated for the pile. It is assumed that the whole structure, including the pile and support structure, is cantilevered at the corresponding fixity length level without surrounding soil while has identical behavior to a pile penetrated the real soil. In this study, the apparent fixity length of the piles sustaining the OC4 offshore wind turbine on the seabed is estimated using a nonlinear soil-pile interaction analysis following a dynamic response analysis of the structure under lateral loads during turbine power production. Given the stiffness coefficients of the pile heads, different apparent fixity lengths are obtained, and the minimum one, verified by modal analysis, is also determined, which can be presumed in fatigue analysis. It is also demonstrated that the estimated minimum fixity length has a smaller value than the piles’ critical length.

In this paper, the lateral load-carrying behavior of inclined micropiles installed in various soil–rock layer conditions was investigated based on the results from the model load tests and finite-element analyses. The effects of micropile inclination angle, load direction, and rock-embedded ratio were considered in the study. Improved load-carrying behavior was obtained from negatively inclined micropiles in rock with the load direction of 0°, whereas it was disadvantageous for the load directions of 90° and 180°. The lateral load capacity of micropiles for the mixed layer condition increased with a rock-embedded ratio and became larger at a higher inclination angle. Marked increases in the lateral load capacity were observed for rock-embedded ratios larger than 0.8, below which the increases were moderate. The inclination and rock-embedded conditions of micropiles were both adequate to enhance the lateral load-carrying behavior of micropiles, whereas the effect of the rock-embedded condition was less beneficial unless largely embedded. It was also indicated that the maximum benefit of micropiles embedded in rock could be achieved by further reinforcing the stiffness in the upper part of micropiles within the soil layer. It was confirmed that the previously proposed method to estimate the lateral load capacity of inclined micropiles in the sand could be effectively used for the case in rock and the mixed soil–rock layer condition for practical purposes. [ABSTRACT FROM AUTHOR]

This article presents the results of complex theoretical and experimental studies on creating universal continuous earthmoving machinery operating under non-standard loading conditions, namely, cyclic lateral loading on the actuator during digging. The lateral loading is due to the complex nature of the actuator motion when digging the soil, namely, the longitudinal motion of the machinery, the actuator digging the soil, and the lateral reciprocating motion of the actuator. This allows for variable width excavations in the soil, whose width exceeds the width of the actuator. The key issue of this machinery operation is to provide its course stability. The article considers the choice of soil-developing actuator and shows the developed calculation schemes of external loading on the operating equipment and a base tractor when digging long excavations in the soil. The dependencies to define external forces acting on the actuator when digging the soil and determining the machinery course stability, considering their spatial nature, have been developed and suggested for practical use. The conditions to ensure the stability of the course of universal earthmoving machinery have been formulated and substantiated. The developed method for determining course stability can be used when creating industrial samples of trenching earthmoving machinery.

Recently, published research indicates that metal/composite hybrid structures, which combine the excellent specific strength and stiffness of composites with the competitive material cost and toughness of metals, have shown superior performance under axial and oblique loadings. Nevertheless, the crushing behaviors under lateral loading are still rarely reported. In this paper, lateral quasi-static planar crushing tests were carried out to investigate the mechanical response and crushing behaviors for aluminum/CFRP hybrid tubes with different configurational schemes (H-I and H-II) by comparing with their counterparts made of singular material (pure aluminum tube and pure CFRP tube). The experimental results indicated that pure aluminum tube showed a stable crushing process and possessed higher EA and SEA compared with CFRP tube. In addition, the EA of H-II hybrid tube was considerably much higher than that of the summation of their constituent components (increased by 110%). The SEA of H-II hybrid tube increased by 90% compared with aluminum tube. In order to further explore the energy-absorbing mechanisms of H-II hybrid tube, the numerical simulations were performed by adopting effective constitutive model and multilayer modeling technique. Based on the developed finite element model, a systematical parametric study was conducted to explore in detail the effects of aluminum wall thickness, the number of CFRP layers, as well as, fiber orientation on the crashworthiness of H-II hybrid tube, and the contribution of different energy-absorbing mechanisms to total energy absorption was quantified. It was found that varying aluminum wall thickness and the number of CFRP layers not only had a great influence on energy absorbed by different mechanism but also was capable to affect lateral stiffness, EA, and SEA of H-II hybrid tube. Finally, the H-II hybrid tube was further optimized by using a discrete optimization method to improve its crashworthiness characteristics, and the results showed that the SEA was improved by 67.9% from the initial design.

Cold-formed steel (CFS) framed construction has been widely adopted and used toward a modern, lightweight, and cost-efficient engineering practice across the United States. The primary objective of this work is to numerically assess the performance of CFS-framed shear walls sheathed with oriented strand board (OSB) and subjected to seismic events. A robust three-dimensional high-fidelity shell finite element model is developed and aims to provide a benchmark modeling approach able to accurately capture strength, stiffness, and failure mechanisms in these systems. Particular attention is given to the fundamental role of the connections between the CFS members and the OSB sheathing to the overall shear wall lateral response. To understand the variability in this critical connection, a series of 30 identical connection tests are performed. The robustness of the proposed computational model is validated by nine different CFS shear wall experimental studies and by a parametric analysis. The developed model is applied to provide an accurate experimentally-derived fastener-based computational tool of CFS-framed shear walls with potential use in design code expansion. [ABSTRACT FROM AUTHOR]

In this paper, we analyze the behavior of a monopile under lateral loading. Specifically, this work focuses on the examination of the static stiffness coefficients of a monopile vertically embedded in a homogeneous or multilayer soil of random geometry and random mechanical properties. To solve the problem, a semi-analytical, closed form solution is developed, based on Winkler's theory. In this model, simulation of the mechanical behavior of the soil is achieved via non-linear "p-y" springs positioned along the axis of the pile, in conjunction with shape functions which describe the lateral movement of the pile. By iterative application of the proposed method the lateral stiffness coefficients at the pile head are calculated with satisfactory accuracy. The results of the proposed method converge satisfactory enough with real data and other theoretical results coming from sophisticated numerical analysis methods. [ABSTRACT FROM AUTHOR]

The framed self-centering wall (FSCW) structure is a newly-emerged special type of seismic-resistant system. However, the related studies rarely concern the theoretical investigation of the FSCW structures subjected to lateral loading, which is of great importance for seismic design of the FSCW structures. In view of this, the analytical model of the FSCW structures is firstly developed, then the fundamental equations that govern the elastic responses of FSCW structures under lateral loads are formulated and the corresponding analytical solutions are derived. Meanwhile, the developed analytical model is validated by the finite element method, which shows that the developed model has a good reliability in predicting the elastic responses of FSCW structures sustaining lateral loading. Utilizing the proposed method, the effects of the post-tensioned (PT) tendon and dampers on the behaviors of the FSCW structure under lateral loading are investigated. Moreover, a comparative study of mechanical performance between the FSCW structure and conventional structures under lateral loading is conducted. The results show that, in terms of the lateral displacement and shear force responses of the frame, the mechanical performance of the FSCW structure subjected to lateral loading generally falls in between those of the conventional frame-shear wall structure and the moment-resisting frame structure. [ABSTRACT FROM AUTHOR]

Gravel is a common geotechnical material in civil engineering. To investigate the lateral bearing behavior of monopile in gravel materials and deeply understand the microscopic mechanisms, parametric three-dimensional discrete element analyses are performed to study the lateral interaction between the single pile and gravel. First, using the experimental data of two typical gravel samples, the discrete element methods (DEM) for monopile in gravel materials are investigated. A discrete particle flow model of pile segments that allows for the construction of p–y curves at various depths is proposed. The lateral mechanical behaviors (p–y curves) between monopile and different gravel material are then studied. The effects of gravel porosity, distribution and grain-size on both the strength and shape of the p–y curves are investigated. The results show that the influences of porosity and depth on the p–y behaviors of gravel are significantly different from those of sand. Furthermore, the obvious differences in p–y behaviors between the coarse gravel and fine sand are the effects of grain size and size distribution. Based on these results, corresponding equations for the estimation of the p–y curves are proposed and further validated by independent field test data. It is concluded that the proposed p–y curve is capable of modeling both different grain sizes and size distributions in gravel-monopile interaction analyses during lateral loading. [ABSTRACT FROM AUTHOR]

In this study, a new hybrid method is suggested for the analysis of laterally loaded pile groups in sandy soils. In the proposed method, a pile group is replaced by an equivalent single pile (ESP) using the concept of two-phase material. Perfect bonding hypothesis and linear elastic behavior are assigned in the application of the two-phase approach. The ESP is analyzed by employing an appropriate single-pile p-y method to obtain a bending moment profile of the laterally loaded pile group. The proposed approach is evaluated by the results of full-scale and centrifuge experimental tests. Good agreements between measured and computed bending moment profiles approved the adequacy of the proposed approach. The properties of the ESP depend on the flexibility factor and slenderness of each pile, as well as pile spacing in the group. The effect of all these parameters is reflected in a factor named κ-multiplier. The effects of various parameters on the κ-multiplier is investigated by parametric studies. Generally, the proposed method provides a simple procedure to analyze the complicated problem of laterally loaded pile groups. [ABSTRACT FROM AUTHOR]

Pile foundations supporting offshore structures, such as jacket platforms and wind turbines, are subjected to cyclic lateral loading. The capacity and deformation of these pile foundations under cyclic lateral loading are important and challenging design aspects. This paper presents the results of a series of four lateral load pile tests in an overconsolidated clay at the Haga site and their back-analysis using a p-y framework based on fundamental soil behavior measured in the laboratory at the element level. This framework can account for site-specific cyclic soil properties, summarized in classic contour diagrams, and site-specific cyclic loading characteristics in design. The paper first provides a summary of the framework and outlines the important assumptions and calculation procedures. It then presents a detailed description of the test setup and soil conditions. The pile load test results and the back-analysis are subsequently presented. Generally, a good match between the test results and the model predictions was observed, demonstrating the model's capability to capture the essential behavior of pile foundations under monotonic and cyclic lateral loading. [ABSTRACT FROM AUTHOR]

The load distribution and deformation of offshore drilled shafts under lateral loading in Incheon grand bridge are investigated by experimental field loading tests and lateral load-transfer approach through p-y curve analysis. The main focus is on improved wedge failure model developed by considering three-dimensional combination forces and new hyperbolic p-y criterion. Through comparisons with field case studies, it is found that the rigidity of the drilled shaft is a critical factor in drilled shafts in marine clay, and the methodology proposed in this study yields more accurate and realistic results considering pile-soil interaction for laterally loaded drilled shafts in marine clay. [ABSTRACT FROM AUTHOR]

Soil-structure interaction is the key to study the behavior of structures under static or dynamic loading. The pile foundation is adopted to transfer loads from the structure to the soil when the structure is embedded in a weak soil stratum. Soil-pile system has a nonlinear behavior; thus, it is more complicated to understand. This study focuses on the numerical investigation of interaction of soil-pile-structure system (ISPS) and interaction of soil-pile system (ISP) under lateral loads. Nonlinear static analysis is carried out considering the lateral capacity of ISPS and ISP systems under lateral loading using pushover analysis. A parametric study concerning different types of axial loading, pile length and pile radius, as well as longitudinal steel ratio in different types of sand is conducted to observe the response of (ISPS) and (ISP) systems. Besides that, lateral capacity deflection and moment curves, as well as the formation of plastic hinge are evaluated for ISPS and ISP systems for a typical pile and various soil types and their results are presented. The results show that the lateral capacity is influenced by the parametric study. [ABSTRACT FROM AUTHOR]

The space elevator system is a space tether system used to solve low-cost space transportation. Its high efficiency, large load, reusability and other characteristics have broad application prospects in the aerospace field. Most of the existing mechanical models are based on “chain-bar” and a lumped mass tether model, which cannot effectively reflect the flexible behaviour of the rope of space elevator system. To establish an accurate mechanical model, the gradient deficient beam elements of the absolute nodal coordinate formulation (ANCF) are used to build the mechanical model of the space elevator system. The universal gravitation and centrifugal force in the model are derived. The calculation results of the ANCF model are compared with the results of the finite element method (FEM) and lumped mass (LM) models. The results show that the calculation results of the ANCF method are not very different from the results of the FEM and LM models in the case of axial loading. In the case of lateral loading, the calculation results of the ANCF method are basically the same as the results of the FEM and LM models, but can better reflect the local flexible deformation of the space elevator rope, and have a better calculation stability than FEM. Under the same calculation accuracy, the ANCF method can use fewer elements, and the speed of convergence is faster than the FEM and LM models.

Shell foundations, or geometrically shaped footings, were first used as a substitute for the conventional flat shallow foundations in the nineteen fifties in Mexico, West Germany, India, China and the Soviet Union. It is not known whether their use was developed independently or was incorporated after observing their use elsewhere. However, it is certain that their use was not based on any research data that has been reported at that time. Since then, the use of shell foundations has drawn considerable interest around the world. Experimental and theoretical investigations by the author on 'shell type' foundations have shown significant increases in bearing capacity, better settlement characteristics, and ability to resist higher lateral forces which might be induced due to wind loads or earthquakes as compared to the conventional flat foundations. This is primarily due to partial absorption of the vertical load through lateral compression of the soil particles under the shell. Given these attributes, the practical implications could make shell foundations ideally suited for foundations subjected to lateral loadings. It is also known that shell foundations require less construction materials, which could benefit its use in developing countries where materials are scarce and expensive while labor is abundant and inexpensive. This paper presents analytical analysis of shell and flat foundations subjected to lateral loading. The results of this study will be presented in the form of a comparative study and numerical example, which will demonstrate that shell foundations are superior to resist lateral loading. [ABSTRACT FROM AUTHOR]

Behaviour of low rise cold-formed steel-framed residential structures when subject to lateral loading (e.g. wind and earthquake loads) is significantly influenced by both structural and non-structural elements. The ceiling is normally considered as a horizontal diaphragm for the distribution of such lateral loads to the bracing walls. In Australia, the ceiling diaphragm, in single and two storey cold-formed steel-framed houses, is made of plasterboard lining fixed to ceiling battens which in turn are screwed to the roof trusses. Determination of the stiffness and strength of the ceiling diaphragm is crucial for accurate distribution of the lateral load to the lateral resisting elements (e.g. bracing walls). This paper presents experimental results from tests of typical ceiling diaphragms. Further, a detailed finite element model is described which was validated against the experimental results. The model is capable of reproducing the initial stiffness, non-linear deformation and ultimate strength. The finding from this work would assist engineers in designing the lateral load resisting system for houses. • Performance of steel-framed ceiling diaphragms is mainly governed by the behavior of the sheathing-to-framing connections. • Ceiling diaphragm test showed a failure of the plasterboard connections at the corners of the specimen. • Presence of end-wall top plate increased the load carrying capacity and displacement capacity of ceiling diaphragm. • Finite element model results showed good agreement with the experimental results. • Design engineer can prepare design charts to provide maximum spacing of bracing walls for houses constructed in Australia. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this in vitro study was to evaluate the fracture resistance and failure modes of endocrowns made of three computer‐aided design/computer‐aided manufacturing (CAD/CAM) materials subjected to thermo‐mechanical cycling loading. Materials and Methods: Eighty mandibular molars were divided into four groups (n = 20): one (C E) was restored with lithium disilicate glass‐ceramic conventional crowns, three were restored with endocrowns made of three different CAD/CAM materials; (E E) lithium disilicate glass‐ceramic, (E V) zirconia‐reinforced lithium silicate glass‐ceramic, and (E C) resin nano‐ceramic. After cycling loading, half of the samples from each group were loaded axially and the other half was loaded laterally. Fracture resistance was recorded in Newton (N) and failure modes were classified. Two‐way ANOVA, Bonferroni post hoc (α = .05), Chi‐square, and multiple logistic regression tests were used to analyze data. Results: Statistically significant interaction were recorded between fracture resistance (N) and loading (P < .001), and groups (conventuional crown and endocrowns; P < .001). Endocrowns presented higher fracture strength than conventional crowns. Fracture resistance was significantly larger under axial loading. The numbers of irreparable failures were extremely important in the endocrowns groups (Groups E E, E V, E C), and only conventional crowns (Group C E) showed almost no irreparable failures under axial loading. Conclusion: Lithium disilicate glass‐ceramic recorded the highest fracture resistance under axial and lateral loading. Clinical Significance: The number of irreparable failures with all endocrown materials tested do not suggest yet the use of this type of restorations in posterior teeth. [ABSTRACT FROM AUTHOR]

In the recent past, in order to cater lateral loads, provision of fins to monopiles is evolving as an option for enhancing their lateral load capacity. Numerical and experimental studies pertaining to fin piles subjected to lateral loading are very limited. It is very difficult to understand the behaviour of fin piles through conventional soil pile theories, due to their different fin configurations. In the present study, three-dimensional finite element analyses were performed on regular piles (pile without fins) as well as fin piles. For fin piles, different fin lengths, orientation and position were considered during the analyses. The results have shown that fins placed at the top portion of the piles are more effective than fins placed at bottom of the pile. In all cases, fin piles exhibited more lateral load-carrying capacity compared to regular piles. When fin's length is less than half of the pile length, lateral load-carrying capacity of fin piles is same irrespective of their orientation. However, fin's orientation is significant, when fin length is more than 0.5 times length of piles, star fin piles exhibit more lateral load-carrying capacity compared to diagonal and straight fin piles. Fin piles experienced less bending moment compared to regular piles for a given lateral load. Further, it was also noticed that lateral load-carrying capacity of the fin piles depend upon fins' length and their orientation. [ABSTRACT FROM AUTHOR]

This study proposes an effective steel frame modular system and evaluates the structural performance of its beam-column connection through experimental and analytical work. The new steel frame modular system utilizes the blind bolts, which allow free access to the structural members of the closed cross-section. In addition, the new modular system is designed such that the strength of its beam members is considerably lower than that of its column members to implement the strong column-weak beam concept. In order to investigate the effectiveness of the proposed modular beam-column connection, two types of specimens were designed and tested. One of the two specimens has four knee brace members to increase the bending stiffness of the connection, while the other does not have these components. The applied load versus displacement curves are plotted for the two specimens, and their failure modes are identified. Finally, a simplified analytical model for the modular beam-column connection is proposed, and its effectiveness is validated by performing its push-over analysis and comparing its results with the test results. [ABSTRACT FROM AUTHOR]

Abstract Large diameter steel pipe pile foundations, typically known as monopiles, are the predominant foundation solution for offshore wind turbines. This paper deals with soil reaction curves for monopile analysis under lateral loading in clay. Developed from extensive parametric finite element analyses, models are proposed that allow for construction of site-specific soil reaction curves based on the stress-strain responses measured in laboratory tests. Assisted by failure mechanisms revealed by finite element analyses, a conceptual framework is proposed to analyse the monopile response under lateral loading using the beam-column approach. The conceptual framework makes use of the p-y model for wedge failure developed in this study along the monopile above the rotation point, existing p-y model for the flow-around failure suggested in the literature below the rotation point and base shear s-u model developed in this study at the pile tip. Validation exercises against finite element simulations and field pile testing results demonstrate excellent capability of the framework to predict monopile responses. The soil reaction models proposed in this paper provide practising engineers with a simple yet powerful approach to use site-specific soil reaction curves in monopile design based on element soil behaviour measured in laboratory, without the need for advanced numerical analyses. Highlights • Soil reaction models that use stress-strain responses measured in laboratory tests as input. • Site-specific soil reaction curves can therefore be used in design, without the need for advanced site specific finite element analysis. • A conceptual framework for monopile analysis using a conventional beam-column approach. [ABSTRACT FROM AUTHOR]

Marine and harbor structures, wind turbines, bridges, offshore platforms, industrial chimneys, retaining structures etc. can be subjected to significant lateral loads from various sources. Appropriate assessment of the foundations capacity of these structures is thus necessary, especially when these structures are supported by pile groups. The pile group interaction effects under lateral loading have been investigated intensively in past decades, and the most of the conducted studies have considered lateral loading that acts along one of the two orthogonal directions, parallel to the edge of pile group. However, because of the stochastic nature of its source, the horizontal loading on the pile group may have arbitrary direction. The number of studies dealing with the pile groups under arbitrary loading is very limited. The aim of this paper is to investigate the influence of the arbitrary lateral loading on the pile group response, in order to improve (extend) the current design approach for laterally loaded pile groups. Free head, flexible bored piles in sand were analyzed through the extensive numerical study. The main hypothesis of the research is that some critical pile group configurations, loading directions, and soil conditions exist, which can lead to the unsafe structural design. Critical pile positions inside the commonly used pile group configurations are identified with respect to loading directions. The influence of different soil conditions was discussed.

Summary: The numerical simulation of soil‐pile interaction problems, by means of full 3D finite element models, involves a large number of degrees of freedom (DOF) and difficulties during the mesh generation process. In order to reduce the unknowns and simplify and properly analyze such class of geotechnical problems, the so‐called embedded beam elements (EBE) have recently been developed. In a preceding contribution of the authors, an improved EBE formulation, which brings into play the soil‐pile interaction surface, was proposed with the aim to localize material plasticity in the soil surrounding the pile. This embedded beam model couples two different finite elements, each described by distinct kinematics (ie, solid and beam). The coupling is incorporated in the formulation by means of kinematical constrains established over the solid and beam displacement fields on the interaction surface. One of the main advantages of the embedded elements is that the addition of beams structural members immersed within the 3D soil model does not represent a constraint for the solid mesh, which can be adopted independently from the beam mesh. In this paper, the lateral loading of pile groups is studied by means of the proposed EBE approach with elasto‐plastic interfaces. In order to represent a rigid cap, a master node and a special set of kinematical restrictions are incorporated into the formulation. The paper presents results obtained by means of the present formulation compared against other well‐established analysis methods and test results published in the literature, for both elastic and elasto‐plastic cases. [ABSTRACT FROM AUTHOR]

Abstract In this note we investigate how the assumption of small deformations affects the estimation of the ultimate resistance to lateral pile movements in clay. For that we perform coupled hydro-mechanical finite element analyses, using the Modified Cam Clay model to describe soil behaviour. Validation of the numerical methodology via small-strain analyses is followed by an investigation on how the ultimate resistance diverges from exact plasticity solutions when large displacements are considered. Results suggest that the failure mechanism depends on the pile displacement required to mobilise the ultimate resistance, and that small-strain plasticity solutions provide upper bounds of the ultimate resistance. [ABSTRACT FROM AUTHOR]

Abstract Evidences from past winter earthquakes and field experiments have shown that seasonally frozen ground can have significant impact on the lateral performance of bridge pile foundations. This paper proposed a modified von Mises model to account for the effects of strain rate, temperature and dry density in simulating the mechanical behavior of frozen Fairbanks silts and presented a procedure for material model updating with strain rate evolution. A FE model was calibrated by using data from field experiments of large-scale steel-jacketed reinforced concrete piles during lateral loading and was then used to conduct inelastic pushover analyses to assess the impact of ground freezing on the laterally loaded pile performance. Modeling results from both the frozen and thawed conditions including lateral load-deflection response, the soil-pile interface behavior including gap size and distribution, yielding and rupture of the steel jacket and rebars, crack/crush of the core concrete, plastic hinge length, displacement capacity, and soil yielding zone were presented and compared. Favorable agreement between the FE modeling results and field experimental data shows that the modified von Mises model and the FE model are capable of capturing the essential features of the frozen soil behavior and the soil-pile interaction during lateral loading. Results reveal that the strain rate within the seasonally frozen layer generally decreases with increasing depth and distance from the soil-pile interface, and variation of three to four orders of magnitude in the strain rate can occur within the seasonally frozen layer. Such large variation in the strain rate can have significant impact on the performance of laterally loaded piles at the frozen condition and its effects should be accounted for. It was also found that ground freezing can transform a soil-pile system from ductile behavior to brittle one, and it is imperative to consider its impact in the seismic design of bridge pile foundations in cold regions. Highlights • Propose a modified von Mises model incorpotating effects of strain rate and temperature for frozen soil fine-grained soils. • Present a procedure for material model updating with strain rate evolution. • Show large variation in strain rates at the same displacement rate on the pile head. • Demonstrate great impact of ground freezing on the lateral performance of piles in seasonally frozen ground. • Reveal that ground freezing transforms a soil-pile system from ductile behavior to brittle behavior. [ABSTRACT FROM AUTHOR]

Highlights • Grouted connection under horizontal loading with axial loads are investigated. • Increasing of axial loads decreases the horizontal bearing capacity and ductility. • Load transferring mechanism through grouted connection is clarified. Abstract Grouted connections are critical parts of the integrity of offshore wind turbine structures since they transfer the upper loads to the lower foundations. In this paper, grouted connection specimens were experimentally studied to investigate the interaction between bending moment and axial load. They were subjected to a horizontal loading with various axial load ratios. The mechanical behavior of these specimens such as bearing capacity, ductility and failure mode was investigated. Furthermore, strain distributions on steel tubes of grouted connection were evaluated to learn the load transferring mechanism. Experimental results showed that grouted connection specimens had good ductility and sufficient bearing capacity. With the increasing of the axial compression level, the lateral bearing capacity and ductility of grouted connection decreased. [ABSTRACT FROM AUTHOR]