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This study presents the results of full-scale tests and three-dimensional finite element analyses of deep cement mixing (DCM) and stiffened deep cement mixing (SDCM) columns under lateral loads and DCM and SDCM walls under deep excavation in soft clay. The DCM walls used in this study comprised one, two and three rows of DCM columns, whereas the SDCM walls consisted of only one row of DCM columns with steel H-beams inserted in either all DCM columns or in alternating DCM columns. The measured and simulated results are presented in terms of profiles of lateral displacement, settlement and bending moment.

This paper presents a numerical study for lateral distortional buckling of I-plate girders (LDBIPGs) by using the general-purpose finite element package ABAQUS (version 6.13) software. 3-D finite element (FE) models for simply supported IPGs subjected to two cases of loading are built. The first case of loading was uniform end moment that was introduced by a couple of forces applied at the top and bottom flanges of the IPGs. The second case of loading was a concentrated load at the shear center in the mid-span. First, shell finite element models are validated by comparing the FE critical bending moment (𝑴𝒄𝒓,𝑭𝑬) by the critical bending moment in EC3 code (𝑴𝒄𝒓,𝒐,𝑳𝑻𝑩). The results indicate that the 𝑴𝒄𝒓,𝑭𝑬 was in good agreement with 𝑴𝒄𝒓,𝒐,𝑳𝑻𝑩. Secondly, a preliminary analysis is conducted to the relative girder slenderness (𝜆) where the LDB too place. Finally, a parametric study is carried out on simply supported IPGs regarding to the span length, the flange cross-section dimensions and the thickness of the web. The results showed that increasing the length of girders decreases 𝑴𝒄𝒓.𝑭𝑬 and increase in the bending coefficient factor (𝑪𝒃). Also, decreasing in the web plate slenderness ratio (𝒉𝒘𝒕𝒘⁄) works on increasing in 𝑴𝒄𝒓.𝑭𝑬 values and 𝑪𝒃. The results also showed that the increasing in the thickness of flange increases 𝑴𝒄𝒓.𝑭𝑬 and increase the value of 𝑪𝒃 with small value. As a result of parametric study, the mean value and standard deviation of 𝑪𝒃 for LDB mode are 1.16 and 0.08 respectively for 𝝀 limits (90:130). For 𝝀 limits (131:175), the mean value and standard deviation of 𝑪𝒃 are 1.27 and 0.03 respectively. As for 𝝀 limits (176:221), the mean value and standard deviation of 𝑪𝒃 are 1.32 and 0.02 respectively.

Adaptation of osteology and myology lead to the formation of hydrofoil foreflippers in Cheloniidae (all recent sea turtles except \(\textit{Dermochelys coriacea}\)) which are used mainly for underwater flight. Recent research shows the biomechanical advantages of a complex system of agonistic and antagonistic tension chords that reduce bending stress in bones. Finite element structure analysis (FESA) of a cheloniid humerus is used to provide a better understanding of morphology and microanatomy and to link these with the main flipper function, underwater flight. Dissection of a \(\textit{Caretta caretta}\) gave insights into lines of action, that is, the course that a muscle takes between its origin and insertion, of foreflipper musculature. Lines of action were determined by spanning physical threads on a skeleton of \(\textit{Chelonia mydas}\). The right humerus of this skeleton was micro-CT scanned. Based on the scans, a finite element (FE) model was built and muscle force vectors were entered. Muscle forces were iteratively approximated until a uniform compressive stress distribution was attained. Two load cases, downstroke and upstroke, were computed. We found that muscle wrappings (m. coracobrachialis magnus and brevis, several extensors, humeral head of m. triceps) are crucial in addition to axial loading to obtain homogenous compressive loading in all bone cross-sections. Detailed knowledge on muscle disposition leads to compressive stress distribution in the FE model which corresponds with the bone microstructure. The FE analysis of the cheloniid humerus shows that bone may be loaded mainly by compression if the bending moments are minimized.

Heinz Isler as the most famous contemporary shell designer has widely employed physical pre-modelling techniques for construction of many concrete shell structures. Through the physical approach to optimal form finding, Isler accomplished shell structures with robust performance. It would be interesting and beneficial to re-assess Isler’s shells, hence, this article attempts to study the structural performance of eight notable shells of Isler. Through reverse engineering and by the assistance of Rhino, MATLAB and Grasshopper, the precise geometry of Isler’s selected shells were modelled for the finite element analysis under their self-weight. The structural analysis was performed, with the parallel use of finite element software SAP2000 and Abaqus. The identical results of the two packages, further confirmed the accuracy of the analysis. The essential properties of various forms of the shells and their differences in behaviour were pinpointed and discussed within the calculations and the results were compared with the data of the genuine published references on Isler’s works. The internal forces, the amount of von Mises stresses, support reactions and the buckling loads of the shells are explored. The analyses revealed that, despite of their major membrane action, all the shells had negligible amount of bending moments, especially near the supports. However, in general, all the shells exhibited an appropriate performance under the applied actions. But, at the same time, they exhibited different buckling behaviour as a probable source of instability in them.

In this study, a series of small-scale laboratory model tests and numerical simulations was performed to investigate the lateral behavior of a single pile embedded in slopes and in horizontal ground. In the model tests, small-scale model piles were fitted with strain gauges around their surface at various depths, while the lateral deflections at the pile head were measured by dial gauges. A total of four sets of model pile tests was conducted with piles installed in model slopes of 0°, 30°, 45°, and 60°. The changes in pile head deflections and their bending moments with changes in pile location and the embedded length of the piles were analyzed by the finite element method (FEM). Subsequently, a new p-y curve (p denotes the soil resistance and y denotes the pile deflection) for a steep clay slope was developed based on those finite element analysis results, taking into account the influences of the declination of the slope and the position of the pile in the slope. The numerical results agree very well with those from a scale model pile load test and other full-scale pile load tests reported in the literature.

The aim of this paper is to investigate the influence of eccentric load and the presence of an opening near the column on the punching shear strength of reinforced concrete (RC) flat slab without shear reinforcement using analytical investigation and numerical simulations. A model based on the finite element method is proposed and its validation is confirmed in this study, by comparing the results with the existing experimental studies available in published literature. Twenty slabs supported directly on columns were analyzed, along with variation of load and opening position in the slab. The punching shear strength for all slabs was calculated according to Eurocode 2 (EC2) and numerically. It was found that the obtained punching shear strength was significantly underestimated by EC2. In addition, this research has shown that the opening position in relation to the direction of the bending moment caused by the eccentric load significantly affects the punching shear strength, while EC2 neglects this position.

We investigate in this Paper the nonlinear aeroelastic response of large horizontal axis wind turbines under a stochastically simulated turbulent wind field, which is instantaneously sampled by the...

Wings with large aspect ratio have large bending moment and torque, so the poor flexural and torsional stiffness are noteworthy. The application of composite materials in wing structure can improve the performance of wing. In the design process of the wing with high aspect ratio, the design parameters of the wing are preliminarily set. Then, the wing configuration is determined according to the force characteristics referring to the indexes of the Predator unmanned aerial vehicle (UAV), and on the basis of the composite material mechanics and finite element theory, the finite element model of the wing is designed as well. Next, we carry out the aerodynamic analysis in FLUENT. At last, we use ANSYS Composite Pre/Post (ACP) module to establish the static analysis of the wing, and two improvement schemes are proposed to deal with the problem that the wing with high aspect ratio would encounter.

The application of carbon nanotubes (CNTs) to improve postbuckling characteristics of T-section nanocomposite strut is the subject of this research. A solution procedure according to the layerwise theory along with the first-order shear deformation theory (FSDT) by taking into account the von Karman geometrical nonlinearity is proposed. Nonlinear governing equations are developed in regard to the minimum total potential energy principle, and solved by the aid of the Rayleigh–Ritz method in conjunction with Newton–Raphson method. A comprehensive parametric study is conducted to provide an insight into effects of CNT volume fraction and dispersion, geometrical parameters and boundary conditions on the bifurcation points and paths, in-plane displacement, normal stress and strain, and bending moment of T-section nanocomposite struts. A three dimensional finite element analysis using the ABAQUS commercial software is carried out to verify the obtained results, which shows close agreement. Results indicate that dispersion of CNTs plays a dominant role in bifurcation behavior of nanocomposite struts. The results also show that volume fraction of CNTs has a significant effect on the load-carrying capacity of open section nanocomposite struts. The results of this research shed light into using ultra-high-strength and light-weight open section nanocomposite struts for civil and aerospace applications.

As the area of land suitable for construction goes on reducing day by day, it is a challenge for civil engineers to utilise the space available in most efficient way possible. This study explores the feasibility of integrating buildings with retaining walls for utilising the maximum space available in commercial zones where the landscape is at different levels demanding the provision of retaining walls. A retaining wall of 6 m height and a multi-storey RC frame having 18 m height in the adjoining lower ground at a distance of 4 m are considered for the study. The effects of integrating the retaining wall to building frame by utilising the 4 m space available between them have been studied by providing a connection through the available space and by attaching the retaining wall as a shear wall to the building leaving no space in between them. The three-dimensional finite element model of the integrated retaining wall-building system has been analysed under dynamic loading. Parameters such as deflection and acceleration at top most storey, bending moments, and shear forces in building components are evaluated. Results are compared amongst different cases of retained soil types and different positions of building from retaining wall. The results show considerable reduction in the building deflection and acceleration when the two structures are connected through the space. Reduction in shear force and bending moment in building components are observed when the two structures are attached to each other without any space in between.

Deep excavations and its impact on neighboring buildings is one of the most important issues when planning to construct new facility. In metropolitan city, it’s a challenging task for the execution of underground construction due to limited space and high cost of land. Hence, this implies that deep excavation has become necessary for the proper utilization of available space. Therefore, it’s important to make sure that adjacent structures are safe against deep excavation-induced deformation. In this study, a two-dimensional Finite Element Method in PLAXIS 2D has been chosen for the soil–structure analysis of deep excavation supported by contiguous pile wall located in Addis Ababa. For the numerical analysis two constitutive models Mohr–Coulomb and Hardening Soil have been applied in drained effective stress condition. The objective of this study is to investigate the effect of deep excavation on adjacent structures by considering support stiffness, ground water condition, neighboring building distance from face of excavation, and building load. The analysis of this study monitors parameters like maximum lateral wall deflection (δhm), maximum settlement (δvm), angular distortion of the neighboring structures, horizontal strain, and maximum bending moment of contiguous pile wall. Moreover, normalization of lateral wall deflection (δhm/He) and settlement (δvm/He) to the excavation depth (He) and neighboring building distance-excavation (D/He) has been presented. Parametric studies have been carried out by varying parameters of diameter of contiguous pile wall, horizontal anchor spacing, and pre-stress force of anchor. The analysis result has been recorded in terms of lateral wall deflection, ground settlement, and bending moment.

Pile foundations are the most vulnerable components of the entire structure and are prone to failure due to earthquake loading. Thus it is mandatory for proper seismic analyses to be conducted with the incorporation of all the necessary influencing factors to ensure no failure occurs to the pile foundation. Even though dynamic analysis has been the conventional seismic analysis method, a new nonlinear static analysis known as pushover analysis is seen to realistically predict earthquake response of the pile. This calls for proper research to be conducted to check if static pushover analysis can be used as an alternative to dynamic analysis for seismic analysis of structures to save time and ease on the complexity of dynamic analysis. In this research work, single piles of different diameter have been taken into consideration which has been embedded in stratified soil containing layers of different soil types. Dynamic analysis and static pushover analysis have been conducted for each case to compare the results of both the analyses. The Finite Element modeling as well as the analyses has been conducted in the user friendly interface of OpenSees known as OpenSees PL. From the results obtained, it is seen that pushover analysis can estimate the maximum bending moment witnessed by the pile while taking into account the effects of surrounding soil condition on it due to earthquake loading. Similar results of maximum bending moment have been obtained for both the analyses.s

Liquid storage tanks are usually located in nearshore or coastal regions with soil profiles containing thick layers of compressible soils. These storage tanks are usually of large diameter up to 90 m and carry high loads, and the tanks are often placed on heavy foundations such as piles. Piles supporting such tanks are to be designed for high lateral loads due to wind and earthquake, and any damage to storage tanks with highly inflammable liquids leads to disastrous conditions (Niigata and Alaska, 1964; 2011 Tohoku), etc. Performance of piles in liquefying ground under earthquake loading has been extensively studied; however, seismic behavior of piles in very soft clays has received relatively less attention, especially on their lateral capacity. The design of laterally loaded piles due to soil movement relies on several theoretical and numerical approaches. The subgrade reaction method (IS 2911 Part-1/Sect. 2: 2010) is most widely used for the design of laterally loaded piles in India and using this method, estimation of the magnitude of soil movement with reasonable confidence and accuracy is difficult. This paper discusses the analysis of lateral load on piles supporting storage tanks using the subgrade reaction method and load-deflection curves (p–y). The scope of this paper is limited to analysis using these methods. The results of the study indicate that the maximum bending moment in the piles that occurred during the earthquake using 3D FEM analysis is comparable to their moment capacities.

Literature and field data from CIREN database have shown that lumbar spine injuries occur during car crashes. There are multiple hypotheses regarding how they occur; however, there is no biomechanical explanation for these injuries during collisions with road safety barriers (RSBs). Therefore, the objective of this study was to investigate the mechanics of vertebral fractures during car collisions with concrete RSBs. The finite element method was used for the numerical simulations. The global model of the car collision with the concrete RSB was created. The lumbar spine kinematics were extracted from the global simulation and then applied as boundary conditions to the detailed lumbar spine model. The results showed that during the collision, the occupant was elevated, and then dropped during the vehicle landing. This resulted in axial compression forces 2.6 kN with flexion bending moments 34.7 and 37.8 Nm in the L2 and L3 vertebrae. It was shown that the bending moment is the result of the longitudinal force on the eccentricity. The lumbar spine index for the L1–L5 section was 2.80, thus indicating a lumbar spine fracture. The minimum principal strain criterion of 7.4% and damage variable indicated L2 and L3 vertebrae and the inferior part of L1, as those potentially prone to fracture. This study found that lumbar spine fractures could occur as a consequence of vehicle landing during a collision with a concrete RSB mostly affecting the L1–L3 lumbar spine section. The fracture was caused by a combination of axial forces and flexion bending moments.

The most important and most frequently encountered combination of construction materials is that of steel and concrete, with applications in multi-story buildings and constructions. The combination of concrete and steel utilizes the compressive strength of concrete and tensile capacity of steel and the resulting composite members offer many structural as well as economic benefits. The recent development of concrete technology resulting in a new type of concrete with many advanced properties, it is called in common name Ultra High Performance Concrete (UHPC). By substituting UHPC to Normal Concrete, the resistance of concrete materials could be reached the resistance capacity of steel and consequently, obtaining optimal load caring of each contribution material. The replacement does not only increase the stiffness and overall ultimate strength but also reduces the cross-section of the composite beams. Furthermore, the need for economical alternatives for steel-normal concrete composite structure and faster construction processes during the erection of structures, boost the investigation in the domain of steel- UHPC composite construction. This study presents a numerical simulation to investigate the structural performance of steel-UHPC Composite Column under axial and flexural loading. Non-linear finite element analysis was conducted, which uses the Concrete Damaged Plasticity (CDP) model. The numerical results of the proposed model showed a good agreement with the experimental result to capture the behavior of steel-UHPC composite column under axial force and bending moment.

Tier derived aggregate (TDA) is a relatively new sustainable light weight fill that has been developed during the last years. This lightweight fill has been utilized in previous studies to study its impact on the response of buried pipes subjected to fault movement induced due to seismic effect. However, these studies did not focus on the impact of using this light weight fill on the performance of buried pipes subjected to transient seismic shake, although recent publications illustrated the significant effect of transient seismic shake on the response of buried pipes. As a step to fill this gap in knowledge, this research has been conducted to investigate the static and seismic performance of a buried concrete pipe that is supported using TDA. The finite element method has been utilized in the analyses using earthquake records that cover a predominant frequency range of 0.93‒2.90 Hz and a peak ground acceleration (PGA) range of 0.15‒0.50 g. The results have also been compared with the case of a buried concrete pipe supported by dense soil. The results showed that the TDA reduces the maximum bending moments induced in the pipe wall by 27% for static condition and by 22‒39% for seismic conditions. In addition, the TDA also reduces the shear forces developed in the pipe wall by 37% for static condition and by 30‒43% for seismic conditions. The percentage reductions of the shear force and bending moment for the seismic condition depends on the frequency and the PGA of the seismic shake. Based on the obtained results, the TDA can be considered as one of the feasible options to be used as material supporting buried concrete pipes subjected to transient seismic shake.

An experimental and numerical study into the global buckling behaviour of structural steel circular hollow section (CHS) beam-columns with normal and high strength steel grades is presented in this paper. Two cold-formed S700 CHS profiles – 139.7×4 and 139.7×5 (diameter × thickness, in mm), were used in the beam-column testing programme. Ten CHS specimens were tested under eccentric compression, resulting in a combination of axial compressive force and uniform first-order bending moment. Digital image correlation (DIC) was used in the experiments to enable full-field monitoring of the strain and deformations in the specimens. Finite element (FE) modelling was also carried out with the aims of first replicating the test results and then generating further numerical data to complement the test data pool. Assessment of the existing EC3 design provisions was carried out against the test and FE data, which revealed that the lack of account taken for the full influence of varying yield strengths leads to inaccuracies in the EC3 resistance predictions. Improved design rules were proposed accordingly and shown to result in considerably more consistent predictions of buckling strength across a wide spectrum of steel grades. Lastly, a reliability assessment of both the EC3 and proposed design approaches was performed in accordance with EN 1990. The statistical results confirmed that the current EC3 partial safety factor is suitable for use with the new design proposals.

The steel constructions of mine shaft steelwork are particularly exposed to aggressive environments, which cause large, nonuniform corrosion loss throughout the steel members. A correct assessment of corrosion loss and load-carrying capacity of shaft steelwork is crucial for its maintenance and safe operation. In this article, we present the results of laboratory, numerical, and analytical investigations conducted on naturally corroded steel guides disassembled from shaft steelwork. The steel guides considered had a closed profile formed by welding two hot-rolled channel sections. Laboratory bending tests were carried out on beams with various levels of corrosion loss, corresponding to compact, non-compact, and slender cross sections. Multiple detailed measurements of the thicknesses of naturally corroded walls were used in order to reproduce their nonuniform geometry in finite element (FE) models. The results of numerical simulations of five bending tests showed good agreement with laboratory measurements and replicated the observed failure modes, therefore confirming the applicability of this modeling approach for assessing the moment capacity of highly corroded steel beams when the deteriorated geometry is known. For the purpose of generalization, a series of derived models reflecting the natural corrosion pattern was then developed, and moment capacity statistics were collected through multiple simulations. They showed that the mean moment capacity is determined by the mean wall thickness. However, the minimum moment capacity is strongly affected by corrosion loss variation, particularly for the highly corroded beams. A simplified, analytical modeling approach was also examined, providing fairly good assessments of the mean, however, the minimum moment capacity could not be estimated. This study contributes to the body of knowledge on the mechanical behavior of highly corroded hot-rolled box-section beams.

Second-generation trapezoidal sheeting, characterised by longitudinal stiffeners in webs and flanges, is loaded near a support by a concentrated force and a bending moment. Currently, design codes predict related failure by: (a) determining the ultimate bending moment via the effective width approach or the Direct Strength Method (DSM); (b) finding the web crippling load via a curve-fitted formula; and (c) using an interaction rule to take into account the load combination. However, the effective width approach is quite complex to use for many longitudinal stiffeners, and the accuracy of the design codes is subject to improvement. Moreover, nowadays the DSM provides a consistent and well-established method to predict ultimate loads for cold-formed steel structures. Therefore, in this paper the application of the DSM for combined bending and web crippling of second-generation sheeting is investigated. First, to create a set of numerical experiments, an internationally representative set of second-generation trapezoidal sheeting types is found, and these types are used to design numerical three-point bending experiments with relevant span lengths and load bearing plate widths. Then, finite element models are developed and verified, and used to predict the buckling, yield, and ultimate loads for the set of numerical experiments. Additionally, all simulations are also carried out for pure bending, and (Interior One Flange) IOF and (Interior Two Flange) ITF web crippling cases. With the resulting data, an explicit DSM approach is developed, fitted to the data of the three-point bending simulations, which predicts the ultimate load for combined actions directly. Hereafter, also an interaction DSM approach is studied, which first predicts the ultimate bending moment by the DSM (by fitting the pure bending simulations), then the web crippling load by the DSM (by fitting either the IOF or ITF simulations), and then uses a classic interaction rule for the load combination. The explicit and implicit DSM approaches perform equally well, with a Coefficient of Variation (CoV) equal to 0.13. As most commercially available sheeting has been incorporated, and the DSM approaches allow for sections with an arbitrarily number of stiffeners in the web (different from the current design codes), it is recommended to include the DSM in future code revisions. The interaction DSM approach resembles the current design rules most and may therefore be preferred; however, the explicit approach is more direct and certainly deserves consideration too.

Tubed-reinforced-concrete (TRC) columns are gaining increasing popularity in engineering constructions, however, research on their fire performance is still limited and mainly focused on concentrically-loaded columns. In this study, extensive numerical analysis was carried out to investigate the performance of square and rectangular TRC columns under eccentric loading and exposed to ISO 834 standard fire. A sequentially-coupled thermo-mechanical finite element analysis (FEA) model was developed in ABAQUS and validated well against fire testing results. The high-temperature overall deformations, internal bending moments and cross-sectional load redistributions of square TRC columns with different load eccentricities were analysed. Parametric studies were conducted to investigate the influences of load eccentricity ratio, sectional aspect ratio, bending direction, fire protection thickness, sectional dimension, load ratio and slenderness ratio on the fire resistance of square and rectangular TRC columns. Load eccentricity was found to have a greater effect on the fire resistances of columns of lower slenderness than those of columns of higher slenderness. Rectangular TRC columns of sectional aspect ratios no larger than 2 could generally achieve identical buckling resistance as that of the equivalent square sections. The influences of sectional aspect ratio and bending direction on the column fire resistance were insignificant. A design method was then proposed for both the ambient-temperature and high-temperature designs of eccentrically-loaded square and rectangular TRC columns. The fire design method could cover both protected and unprotected TRC columns. The design method has been thoroughly validated against detailed FEA modelling and yields excellent agreements with the modelling results.

When reinforced concrete (RC) slabs are supported directly on columns, a combination of shear forces and unbalanced bending moments is transferred between the slab and the columns at slab–...

Stretch Forming Lattice Structure (SFL), composed of upper chord, lower chord, vertical web member and lateral support member, is a self-balance structure. Using APDL (ANSYS Parametric Design Language), static analyses are conducted for the fully forming process of SFL with a long span of 90m. Result show that both geometrical and material nonlinear analysis of structure is necessary to SFL, and the upper chord is the most important prestress-carrying members in the forming process in comparison with the vertical web and the lateral support members etc, and mainly subjected to the bending moment in comparison with the axial force. SFL with merits of rationally mechanical characteristics, novelty of constructional detail and convenience of execution will have great prospect.

The berthing structures including piles and diaphragm walls are supported on soft marine soils. The soft soils under severe loading are likely to undergo vertical and lateral movement. The anchored diaphragm wall is provided to support the open berth structure against backfill. In this paper, finite element analysis of berthing structure has been carried out using a finite element program ANSYS APDL. The soil strata is modelled as 3D continuum. The response analysis of diaphragm wall for different pretension forces in anchor rod has been carried out. The variation in displacement, shear force and bending moment along the depth of wall is plotted. The result is compared with the case without considering soil–structure interaction. The optimum value of pretension force is obtained as 1050 kN which effectively reduced the deflection of diaphragm wall. The percentage increase in maximum lateral displacement, shear force and bending moment of wall without considering soil–structure interaction effect was found to be 25.265%, 52.523% and 892.944%, respectively.

The present study focuses on comparative parametric analysis of curved precast concrete bridges using straight and curved I-girders. The live load bending moment distribution for girders was studied using the bridge curvature and its relationship with the results obtained for a straight bridge. FEM 3D models were developed with restrictions on the transverse live load positions and with two different load models types: HL-93 (AASHTO) and TB-450 (NBR 7188, 2013). The parametric analysis results were calculated using the Modification Factor (MF) and the Bending Moment Distribution Factor (BMDF), calculated from the structural analysis of each model at the midspan. Globally, an increase was found in the total bending moment for the curved bridge models in relation to the straight bridge. In the examples herein studied, the larger the bending radius, the larger the maximal bending moment in the bridge center. For the external girders, the MF increases with the increase of the L/R. For the internal ones, the MF decreases with the increase of the L/R. In addition, the occurrence of “Load Shift” was different from the rigid body behavior, for there was demonstrated a different bending moment variation between external girder (G1) in relation to its adjacent (G2). Therefore, the structural behavior of straight (SG) and curved girders (CG) was analyzed, revealing that, in the SG, a significant gap occurred in the BMDF between G1 and G2 girders for all curvatures. For L/R = 0.6, it caused a difference of 17.8% in the BMDF between the G1 and G2 girders, while on the curved girders, a difference of only 6.6% was found. resumo: o presente estudo foca na análise paramétrica comparativa de pontes curvas utilizando utilizando longarinas retas e curvas pré-moldadas. As análises foram baseadas na distribuição transversal de momento fletor para a longarinas, na variação da curvatura da ponte e na relação desses parâmetros com os resultados obtidos em uma ponte reta. Foram desenvolvidos FEM 3D models com restrições nas posições transversais da carga-móvel e com dois tipos diferentes de modelos de carga: HL-93 e NBR 7187. Os resultados da análise paramétrica foram determinados utilizando o Fator de Modificação (FM) e o Fator de Distribuição de Momento Fletor (FDMF), calculadas a partir da análise estrutural de cada modelo na posição longitudinal do meio do vão. No âmbito global, contatou-se um aumento do momento fletor total nos modelos de ponte curva em relação à reta. Nos exemplos estudados, quanto maior o raio de curvatura, maior foi o momento fletor máximo no meio do vão da ponte. O valor de FM varia linearmente. Para as longarinas externas o FM aumenta com o aumento do L/R, já para as internas, o FM diminui com o aumento do L/R. Além disso, foi comprovada a ocorrência de “Load Shift” diferente do comportamento de corpo rígido, tendo em vista a variação diferenciada de momento fletor para a longarina externa G1 em relação a sua adjacente G2. Constatou-se uma diferença considerável de comportamento estrutural entre as longarinas retas e curvas, tendo em vista que nas SG ocorreu uma diferença significativa de FDMF entre a longarina G1 e a G2 para todas as curvaturas, o que não ocorreu para as CG. Para L/R=0.6, observou-se uma diferença de 17.8% no FDMF entre as longarinas G1 e G2 retas, já nas longarinas curvas, a diferença foi de apenas 6.6%.

Due to their simplicity, analytical approaches based on the limit equilibrium approach have been used in the design of sheet pile walls for many years. However, due to a lack of understanding of the elastic behavior of the sheet pile wall and stress concentrations, some overestimations in values of maximum bending moment and anchor force may occur. These shortcomings have let an increment in the use of numerical models. In the present study, excavation work in the sand that has various fiction angles to be supported by a single anchored sheet pile wall was solved considering the ground water level and varying the anchor level from the soil surface. The effects of the solution method, soil friction angle, and anchor level on the embedment depth, anchor force, and maximum bending moment for sheet pile design are investigated using the free earth support and fixed earth support methods as analytical methods and the finite element method (FEM) as a numerical method. The Matlab R2015a program is used to execute analytical solution methods, while PLAXIS 2D V8.2 is used to do finite element (FE) analysis. The findings of embedment depth, anchor force, and maximum bending moment versus anchor level and friction angle of soil, null , are presented, illustrated, and discussed, in detail. As a consequence of the study, it is observed that the solution method, friction angle of soil, and anchor level have a significant effect on the design of the single anchored sheet pile wall and that the results of the fixed earth support method correlate better with the results of the FEM in comparison to the free earth support method.

The effect of loading type (tension, compression and bolt-bearing) on mechanical properties (elastic modulus, Poisson’s ratio and ultimate strength) of Moso bamboo (Phyllostachys heterocycla var. pubescens) in longitudinal direction was evaluated in this study. In addition, experimental and numerical tests were conducted to evaluate withdrawal force capacity and bending moment resistances of a novel demountable bamboo-bolt joint considering effect of loading type on mechanical parameters used in finite element method. The results showed that loading type had significant effect on mechanical properties of Moso bamboo, especially, for ultimate strength; the values of mechanical properties evaluated in this study measured in tension were all much higher than those measured in bolt-bearing state and followed by compression accordingly; in tension, the tensile elastic modulus and Poisson’s ratio measured at outer surface were bigger than those at inner surface, respectively; finite element method got more accurate results using the mechanical parameters measured in compression than those in tension and bolt-bearing states; the bamboo-bolt joint proposed in this study can be used in lightweight bamboo structures through improving the embedding strength of beech wood in bamboo culm. In conclusion, one should consider the loading type used to obtain the mechanical parameters inputted in finite element method. In addition, further studies will focus on effect of size and geometry of samples used to determine mechanical properties used in finite element method, and the method of improving embedding strength of beech wood in bamboo culm to increase withdrawal force capacity and bending moment resistances of the demountable bamboo-bolt joint proposed in this study.

Based on the finite element (FE) analysis software Abaqus, an FE model of square-cased square steel tube reinforced concrete (ST-RC) columns under the hybridized action of high-temperature and load is established. The accuracy of the FE model is verified using experimental data from existing studies. This model is used to analyze the temperature change, internal force distribution, and failure characteristics of the square-cased square ST-RC columns under the action of fire, as well as the factors affecting the fire resistance limit of the column. The results of FE analysis show that under the action of fire, the maximum internal temperature of the square-cased square ST-RC columns occurs in the corner of the section. Moreover, the stress and strain reach their maximum values at the concrete corner outside the tube. During the heating process, an internal force redistribution occurs in the square-cased square ST-RC column. At the same time, the proportion of the axial force and the bending moment of the reinforced concrete outside the pipe decreases gradually, while the proportion of the internal force of the core concrete-filled steel tube (CFST) increases gradually. In essence, it is a process of load transfer from the high-temperature to the low-temperature zone. In addition, the section size, load ratio, slenderness ratio, cross-sectional core area ratio, steel content, and external concrete strength are the main parameters affecting the fire resistance limit of the square-cased square ST-RC columns. Among them, the cross-sectional core area ratio, section size, steel ratio, and external concrete strength are positively correlated with the fire resistance limit of the composite column. On the contrary, with the increase in the load ratio and the slenderness ratio, the fire resistance limit of the square-cased square ST-RC columns decreases. On this basis, a simplified formula to calculate the fire resistance limit of square-cased square ST-RC columns is proposed. The research results can be used as a theoretical reference for the fire protection design of this kind of structure in practical engineering.

Earthquake-induced liquefaction increases the pore water pressure, reducing soil stiffness and allowing lateral movement of crust layer above the liquefiable layer, considerably damaging the piles. In this paper, an attempt is made to investigate the response of piles under liquefaction using a spectrum-compatible accelerogram corresponding to the maximum credible earthquake for the most severe seismic zone of Indian standards, with finite element model (FEM) in the OpenSees platform. It is predicted that the maximum pile head deflection, bending moment, and shear force is 3.66, 15.31, and 3.09 times that pile responses due to non-liquefied soil condition, respectively. Further, a mitigation technique is proposed using rubber–soil mixture (RSM) around the pile. It is estimated that a 10% reduction in maximum pile head displacement is achieved with 1-m depth RSM layer, while the reduction of 40% and 60% is achieved with RSM depth 2.5m and 4m, respectively. Responses due to proposed FEM modeling in close agreement with that of SAP modeling using the Euler–Bernoulli-beam model.

This research study presents a closed form solution of responses of laterally loaded long piles embedded on cohesive soils with a constant subgrade modulus. The surrounding soil medium is modelled as elastic-perfectly plastic. The closed form solution is derived by solving the governing differential equation of the pile–soil system. The most popular numerical computation software package MATLAB is utilized for the implementation of solutions. The provided analytical method reliably calculates the pile head deflection and bending moment required for engineering design purposes. Results are discussed and verified with solutions of an equivalent three-dimensional finite element (FE) model developed using ANSYS software. It was concluded that the proposed analytical model could efficiently provide the exact solution of embedded piles in elasto-plastic cohesive soil under lateral loads.

Nowadays, the uses of concrete-filled steel tubular (CFST) columns have been significantly increased in civil engineering infrastructures due to their inherent ductility, high load-bearing capability and excellent energy absorption capacity. This paper presents both experimental and numerical investigations on the structural responses of built-up slender square concrete-filled steel tubular (SCFST) columns under uniaxial eccentric compression. In this study, a total of eleven welded built-up slender SCFST columns were tested with nominal concrete cylinder strengths of 27 MPa, 35 MPa and 44 MPa, respectively. The effects of different parameters including the concrete strength, column overall slenderness ratio, plate slenderness ratio and variation of eccentricities on the buckling modes, ultimate axial strength and post-peak ductility of the specimens were investigated. The test results indicated that the ultimate strength of the columns varied inversely with the load eccentricity ratio. The concrete grades have significant influence on the load-bearing capacity and ductility of the columns. Moreover, the ultimate strength as well as ductility of the tested specimens moderately decreased with the increase of column overall slenderness ratio and plate slenderness ratio, respectively. Thereafter, ABAQUS software was used to develop the finite element (FE) models of the tested specimens. The developed FE models of built-up slender SCFST columns were validated by comparing the simulated results with test results. It was found that the proposed FE models are capable to predict the structural behavior of built-up slender SCFST columns with high accuracy. Finally, the test results were compared with the corresponding failure loads and ultimate bending moments predicted by the EN 1994-1-1 provisions, which appear slightly insecure.

Traditional glulam beam connection mode has a weak ability to transfer bending moment, leading to insufficient joint stiffness and mostly in the form of simply supported beams. To make full use of material strength, a novel prestressed glulam continuous beam was proposed. On this basis, this paper put forward a new method to further improve the mechanical performance of the beams by controlling prestress. According to the estimated ultimate loads of the beams, six different control range values were formulated, and 12 continuous beams were tested for flexural performance. The effects of prestressing control on the failure modes, ultimate load capacity, and load versus deformation relationships of the glulam continuous beams were analyzed. The test results indicated that the flexural performance of the beams with prestressed control was significantly improved compared to the uncontrolled beams, the ultimate load was enhanced by 13.60%–45.11%, and the average steel wire stress at failure was increased from 70% of the designed tensile strength to 94%. Combined with the finite element analysis (FEA), the reasonable control range of the prestressed control continuous beams was18%–30% of the estimated ultimate load. The research in this paper can provide references for the theoretical analysis and engineering application of similar structures.

Piled raft foundations (PRFs) are essential for improving the load-bearing capacity of the foundation and for controlling the total and differential settlements. For an efficient design of the foundation for high-rise buildings, components of PRF such as length, diameter, and raft thickness are important factors. This study aims to examine the interaction behavior of pile–soil foundations for various parameters, namely the diameter and the length of the pile and also the raft thickness, which plays an important role in improving the behavior of piled raft foundation. The important aspects that must be taken into account to achieve a reliable design and strategies for the optimized design of PRF that is subjected to load–settlement with regard to the distribution of shear force and bending moment are also analyzed. In order to understand the behavior of piled raft foundation subjected to uniform loading, numerical simulations are carried out in this study by using a numerical tool based on the finite element method (FEM), ELPLA. This study reveals that proper pile arrangement can result in a significant reduction in the total and differential settlements, as well as induced shear force and bending moments on the raft.

This paper presents a numerical study of 3 × 3 pile groups embedded in clay under vertical and inclined eccentric loads. Simplified modelling, based on elastic beams embedded in a soil continuum, is used to explore the soil-pile-cap response. This simple model allows rigorous treatment of the 3D foundation geometry and local soil plasticity, demonstrated through validation with 3D finite element analysis. The numerical results reveal that complex roto-translational displacements of the pile group are induced by eccentric or inclined loads, with highly nonlinear relationships when soil plasticity is considered. Interestingly, vertical eccentric loads mobilise the lateral soil resistance at large cap displacements. Thus, while existing t-z type models are shown to be adequate for serviceability predictions, they could provide overly-conservative estimates of the ultimate load capacity. Also, foundation internal forces can exceed allowable bending moments of reinforced concrete piles under multi-directional loads. For performance based design of pile groups under inclined eccentric actions, engineers should estimate the impact of soil yielding on both displacements and rotations of the cap, to satisfy limit state requirements. Dimensionless charts are presented, which describe the reduction in vertical capacity, for a prescribed cap displacement, as a function of load eccentricity and inclination.