Effect Of Lateral Loads Research Articles

Finite Element Modeling and Analysis of RC Shear Walls with Cutting-Out Openings

In recent decades, reinforced concrete (RC) shear walls have been one of the best structural solutions to resist lateral load in high-rise buildings. Shear wall openings are essential for preparations and architectural requirements, which weaken the wall, reducing bearing capacity, energy absorption, and stiffness while also causing stress concentrations. This paper presents a comprehensive finite element (FE) investigation of the behavior and performance of RC shear walls with openings and subjected to lateral loads. The study aims to evaluate the influence of various parameters, such as opening location, size, wall aspect ratio, axial load, and concrete strength, which affect the performance of shear walls. FE models were developed to simulate the seismic response of RC shear walls under the combined effect of constant axial and lateral loads. The obtained results from the FE model showed a successful validation using the experimental data available in the literature. The FE analysis results demonstrate that the inclusion of lower openings leads to a 25% decrease in the bearing capacity of the wall when compared to the upper openings. Moreover, it was observed that augmenting the sizes of the openings and the aspect ratios of the wall resulted in declines in the strength, stiffness, and energy absorption capacity of the wall while simultaneously enhancing the ductility and displacement of the RC shear walls.

Effect of Lateral Load to the Behavior of Single Piles Subjected to Earthquake Load in Sand

In fact, pile usually carry static and dynamic load in same time, the case of simulations lateral and dynamic load is possible occurred. This case is not cover enough by previous researches especially by laboratory model. Therefore, the purpose of this study is to determine the extent to which altering the horizontal lateral loads impacts the behavior of individual piles during seismic events. An experimental test was devised using a physical model with an advanced shaking table that using El Centro earthquake. Sandy soil with 65% relative density used raining technique. Lateral loads were applied at levels of 0%, 50% and 100% from allowable lateral load capacity. It was observed that when lateral load increased from 0% to 50% and 100%, the lateral displacement response decreased by 32.10% and 49.59% respectively. While the vertical displacement increased by 49.96% and 76.95%. Finally, the acceleration decreased by 34.39% and 41.03%. This is possibly due to the load acts at an angle opposite to the earthquake as a restraining factor for the pile. led to a decrease in lateral displacement, vertical displacement, and peak ground acceleration.

Assessing the effects of horizontal loads on the ultimate vertical bearing capacity of energy piles: A comparative numerical and analytical study

Previous studies have not extensively explored the collective impact of lateral, axial, and thermal loading on the ultimate vertical bearing capacity of energy piles, qu. This study investigates qu 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 qu values in sandy soil. Both numerical and analytical solutions show that cooling and heating can respectively increase and decrease qu under corresponding conditions. Numerical simulations indicate that in clay, lateral load enhances qu, 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 qu 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 qu values under different thermomechanical conditions.

Effect of combined lateral and uplift loads on vertical and batter pile groups in cohesion less soil

Effect of combined lateral and uplift loads on vertical and batter pile groups in cohesion less soil

Foundation Types of Fixed Offshore Wind Turbine

Offshore wind turbines are supported by various foundations, each with its considerations in design and construction. Gravity, monopile, and suction bucket foundations encounter geotechnical issues, while jacket and tripod foundations face fatigue problems. Considering this, a gravity foundation based on a steel skirt was developed, and a monopile foundation was analyzed for Pile-Soil Interaction using the p–y curve and 3D finite element method (3D FEM). In addition, for suction bucket foundations, the effects of lateral and vertical loads were analyzed using 3D FEM and centrifuge tests. Fatigue analysis for jacket and tripod foundations was conducted using a hotspot stress approach. Some hybrid foundations and shape optimization techniques that change the shape to complement the problems of each foundation described above were assessed. Hybrid foundations could increase lateral resistance compared to existing foundations because of the combined appendages, and optimization techniques could reduce costs by maximizing the efficiency of the structure or by reducing costs and weight. This paper presents the characteristics and research directions of the foundation through various studies on the foundation. In addition, the optimal design method is presented by explaining the problems of the foundation and suggesting ways to supplement them.

A Review paper on seismic response of various slab systems with and without lateral load resisting systems

With the ongoing modern trends of the construction industry, slab systems like flat slab and post tensioned slabs are widely used in the construction. Flat and post tensioned slab are widely favored by architects and clients for aesthetic reasons. They also do possess a huge advantage structurally over conventional slab arrangement such as Less depth of the slab is required , increasing the floor-to-floor height , longer spans are possible , no beam projections , reduced self-weight of the building and many more. But it comes with its own disadvantages as well such as Brittle punching (shear) failure. Which requires additional reinforcement along the connections of column and slab. Which increases the longitudinal steel required. Slab – column connections are the first point of yielding in higher seismic zones with buildings without lateral load resisting system (LLRS). In higher seismic zones the slabs can resist only the gravity loads and can’t resist the lateral dynamic loading and hence may require additional lateral load resisting system (LLRS) to resist lateral loads such as seismic and wind loads. Thus it becomes essential to study the seismic behavior of conventional slab , flat slab and post tensioned slab systems in high rise RCC structure with and without various LLRS ( lateral load resisting system).This study is aimed to study various literatures related to effects of lateral loads on flat and post tensioned slab system and different LLRS (lateral load resisting system) to make the structure more resistant and economical against such lateral loads considering parameters like story displacement , base shear , stiffness of the connections and time period.

Effects of Simultaneous Torsional and Lateral Loads on Shaft Piles with Fins in Sandy Soil

Effects of Simultaneous Torsional and Lateral Loads on Shaft Piles with Fins in Sandy Soil

Pushover Analysis of Different Shapes of Symmetric and Asymmetric Reinforced Concrete Buildings as per BNBC 2020

Bangladesh is situated in an earthquake-active region. It is necessary to identify structures at risk of damage and implement an effective safety standard. This evaluation requires methods beyond simplified linear-elastic approaches. As the number of high-rise buildings is increasing daily, there is an urgent need to design structures considering seismic loading. Although different procedures are possible, to assess how well a structure performs, the non-linear static analysis, also referred to as Pushover Analysis (or collapse analysis), is seen as a practical method. In the present study, four different shapes of multistoried buildings were analyzed according to BNBC 2020. At first, a model was prepared; loading was done and analysis was run using Etabs v16.2.1 (structural analysis and design software). The results show that the effect of lateral loads due to earthquakes is different in the case of different building shapes and how a building behaves during earthquakes is mostly influenced by its overall geometry and shape.

Numerical investigation on lateral monotonic and cyclic responses of scoured rigid monopile based on an integrated bounding surface model

Offshore wind turbines (OWTs) are affected by wind, wave, and current during their service life, which lead to the substructures undergoing combined effects of complex lateral loads and local scour. This phenomenon poses a significant challenge to the bearing capacity and cyclic responses of the widely used rigid monopiles for OWTs. This study develops three-dimensional numerical model to investigate the behavior of a rigid monopile subjected to lateral monotonic and cyclic loads, considering the stress history alteration induced by local scour. The hysteresis and plasticity accumulation of soils are captured by a bounding surface model. An accurate and concise semi-implicit stress integration scheme is creatively proposed to effectively incorporate this advanced constitutive model into the finite element (FE) software. The numerical model is verified by comparing FE results with centrifuge test results. Subsequently, the key factors such as cumulative deformation characteristics and bending moments distribution are investigated under different scour and cyclic loading conditions. The results indicate that with the facilitation of proposed semi-implicit scheme, the bounding surface model is capable of capturing the deformation pattern and cumulative deformation behavior of laterally loaded rigid monopile, and the cyclic responses of the monopile are significantly affected by the local scour.

An experimental study of the effect of lateral static load on cyclic response of pile group in sandy soil

Abstract The application of two different lateral loads (i.e., the first is static and the other is cyclic load) at the same time to pile group seems a complex problem. So, this study is concerned with the interaction of these loads together and includes laboratory tests to determine the effect of the static lateral load on the lateral cyclic capacity of the 2 × 2 pile group with three distances (S/D = 3, 5, and 7). The experimental program included small-scale laboratory setup by using hollow piles of aluminum and sand rain method for the preparation of sandy soil medium. The results showed that increasing the static lateral load led to reducing the lateral displacement, and the average value of decrease for the three distances reaches 72%. It can also be concluded that the distance S/D = 3 is more affected by the increase in the static lateral load than other distances, where the average decrease in the lateral displacement was about 83, 74, and 60% when S/D = 3, 5, and 7 sequentially.

A Feasibility Study on the Lateral Behavior of a 3D-Printed Column for Application in a Wind Turbine Tower

Although 3D printing technology has been applied worldwide, the problem of connecting a printed structure and a foundation has rarely been examined. In particular, loads in the horizontal direction, such as wind loads and earthquake loads, can significantly affect the stability of a printed structure. Therefore, in this study, the effect of lateral loads on printed columns that were connected to a foundation by two types of connectors was investigated. A steel angle with bolts and couplers was used to connect the printed column to a concrete footing. In addition, two types of lateral reinforcement were applied to the printed column to enhance its bonding strength and shear resistance. The lateral reinforcements were attached to the interface of the printed layers at distances of 100 and 200 mm to investigate the effect of lateral reinforcement distance on the lateral behavior of the printed column. The results showed that the use of couplers as connections between the columns and foundation significantly improved the load capacity. Furthermore, the effects of the lateral reinforcement types and lateral reinforcement distances were assessed.

Effect of long-term lateral cyclic loading on the dynamic response and fatigue life of monopile-supported offshore wind turbines

Offshore wind turbines are often supported on monopiles and are always subjected to long-term cyclic loading during their service life. This cyclic loading induces changes in the damping, stiffness and permanent accumulated rotation of the monopile foundation. The main purpose of this paper is to investigate the effect of these three changes occurring simultaneously on the dynamic response and fatigue life of offshore wind turbines in sand. To this end, an integrated methodology is presented based on time-domain finite element model and small-scale model tests of rigid piles. Three states of the monopile foundation are selected and defined based on the operational time of the turbine. The results show that these three changes have a slight effect on the dynamic response of offshore wind turbines, but have a significant effect on the fatigue life. The fatigue life decreased from 23.3 years for the initial state to 20.99 years for the medium state and 19.45 years for the ultimate state, a decrease of 10% and 16.5%, respectively, indicating that these changes should be addressed in the design of the fatigue life calculation of offshore wind turbine structures. The systematic parametric analysis shows that soil damping has the greatest effect on the dynamic response and fatigue life, followed by soil stiffness, which is less affected by permanent accumulated rotation.

Combined effects of axial and lateral loading for Glued-In steel rods in laminated veneer lumber

Glued-in rod timber connections are used to achieve structural continuity in timber structural members and as moment connections due to their high efficiency, stiffness and axial load transition. Existing studies have focused on axial withdrawal load capacity but there is limited research on laterally loaded glued-in rods and combined effects of lateral and axial loading which is common loading condition for all connections. This study investigates the relationship between axial and lateral loading in the ductile failure modes of glued-in steel rods in hardwood LVL. In all specimens an unbonded length was provided based on the latest design recommendations to mitigate splitting failure. The experimental findings suggest that the introduction of lateral load had no effect on the axial load capacities of the rods when the governing failure mode was rod yielding. This is not currently addressed in Eurocode 5. The lateral force capacity exceeded the design code prediction by 82%, and design recommendations are discussed for more accurate estimation of the lateral capacity. The use of the component method can be adopted to estimate accurately the rotational stiffness of moment connections with glued-in rods in LVL.

Buckling Strength of Cold‐Formed Stiffened Thin‐Walled Steel Box Bridge Piers under Cyclic Loading

AbstractThis paper presents numerical simulations on the behavior of thin‐walled steel tubular bridge piers of box sections under cyclic lateral loading in the presence of constant axial compression loads, using three‐dimensional finite element analysis adopted in commercial computer software ABAQUS. The analysis and experimental results are compared to show how the adopted material models, such as elastic perfectly plastic (EPP), kinematic hardening (KH), and isotropic hardening (ISO) material models are effective and reliable for capacity prediction and cyclic behavior evaluation. The effects of cyclic lateral loading on the hysteresis behavior of the thin‐walled steel tubular bridge piers of box sections have been evaluated by analyzing the hysteresis curve, envelope curve, stiffness, and strength degradation characteristics, considering the interaction of local buckling and flexural buckling. In contrast to the ISO and EPP material models, the analysis results compare reasonably well with test results using the KH material model.

Numerical assessment of the cyclic behaviour of structural steel members subjected to biaxial bending

AbstractIn recent decades, there has been extensive research on the behaviour of steel structures under seismic actions. While the monotonic behaviour of steel elements subjected to uniaxial bending is well understood, there is still a need to investigate the cyclic behaviour and energy dissipation capacity, especially in relation to metal elements subjected to biaxial bending. This is of paramount interest for seismic analysis and performance assessment of steel buildings. Modelling and damage assessment criteria derived for members subjected to uniaxial bending may not be entirely appropriate for the seismic analysis of buildings composed of structural steel members subjected to biaxial bending. Therefore, this research aims to investigate the behaviour of steel members subjected to biaxial cyclic bending and compare it to behaviour under uniaxial loading conditions. To this end, detailed 3D finite element analyses are conducted to examine the effects of bidirectional lateral cyclic loading on the hysteretic response of steel members under different uniaxial and biaxial lateral displacement‐controlled load paths. The numerical results presented in this paper provide an insight into the influence of biaxial loading on the behaviour of steel members in terms of backbone curves and deformation capacity, and indicate that biaxial cyclic loading paths can significantly affect the rotation capacity of steel elements.

STRENGTH AND DUCTILITY EVALUATION OF THIN-WALLED STEEL TUBULAR BRIDGE PIERS UNDER CYCLIC LOADING

Numerical simulations are being conducted on the behavior of thin-walled steel tubular bridge piers under cyclic lateral loading in the presence of constant axial compression loads. The effects of cyclic lateral loading on the behavior of the thin-walled steel tubular bridge piers have been evaluated through analysis of the hysteresis curve, envelope curve, stiffness, and strength degradation characteristics, and energy-dissipating capacity, including interaction effects of local buckling and flexural buckling, and post-buckling regimes. This study also compares the numerical analysis with experimental results available in the literature to validate the accuracy of the proposed finite element model. Based on this model, a range of relevant material and structural parameters will be investigated in future work. Numerous numerical specimens will be designed and analyzed, gaining further information about the influence of width-to-thickness ratio, Rt, column slenderness ratio, , material properties of the embedded shell plate, spacing of transverse stiffening ribs of the shell, height, and properties of partially infill concrete, and axial compression load.

Effect of Lateral Load on the Mechanical Properties and Failure Modes of Sandstone Brazilian Discs during the Biaxial Splitting Test

Abstract To study the mechanical properties and failure modes of the Brazilian disc under biaxial splitting loading, different stress ratios (i) (axial stress:lateral stress) i = 1:1, 2:1, 3:1, 4:1, and ∞:1 are experimentally applied in sandstone discs by a hydraulic servo-controlled testing machine equipped with a lateral loading device. Meanwhile, digital image correlation (DIC) and the FLAC3D are used to obtain the strain field and stress field evolution of the specimens. It was found that the presence of lateral pressure limits, the formation of horizontal tensile stress to varying degrees, and the axial peak loads decrease with the stress ratio. The failure modes that the rock discs underwent were shear failure, shear-tension mixed failure, and tensile failure as the stress ratio increased. The DIC results show that the maximum strain field gradually transitioned from the adjacent loading points of the discs to between two loading points in the axial direction with the stress ratio. In addition, the simulation results also demonstrated the transformation of the dominant stress in the stress field from tensile stress to shear stress with increasing lateral pressure.

Experimental study on cyclic lateral response of piles in sandy sloping ground

This study aims to experimentally investigate the cyclic lateral responses of piles in sloping ground. The effects of slope angle θ, number of cycles n, and loading pattern (static or dynamic) on the pile responses (inc. unloading stiffness and residual displacement) were revealed by a series of laboratory (1-g) model tests considering the combined effects of slope and cyclic lateral loading. The measured responses indicated that all the pile head displacement, bending moment, lateral earth pressure, and unloading stiffness increase non-linearly with n. Thereinto, the pile head displacement x can be fitted by the function x = A(θ)n0.1 where the coefficient A(θ) is linearly related to tanθ; the residual displacement decays exponentially with the number of cycles. In addition, the slope effect would exacerbate the pile responses under cyclic loading, for instance, the maximum bending moment is linearly related to tanθ, and the depth of contraflexure point increases by 0.14 times the pile diameter when the slope angle increases by 1°.

Effect of Lateral Load on Local Buckling of Latex Wrapped Cold Formed Steel Columns

This paper reports the experimental investigation conducted on unwrapped and latex wrapped cold-formed steel column. Various column cross-sections are subjected to repeated lateral loading till failure. All the columns were observed to fail in local buckling. The column cross-section dimension, provision of interior and exterior lip, and the latex wrapping of the columns influenced the lateral load to failure. Increasing the web length of a column section from 100 to 200 mm increased the load-carrying capacity of the column by 70 to 100 %. The local buckling was initiated in the flange portion of the column. The column section with no lip and interior lip exhibited inward buckling of the flange. The column with exterior lip exhibited outward buckling. The provision of lip and latex wrapping did not influence the initial load-displacement behavior of the columns. However, it increased the load-carrying capacity of the sections. Energy absorption index and ductility factor were calculated and the effect of latex wrapping of the columns on these parameters was evident.

Lateral behavior of monopiles under the simultaneous effect of vertical-lateral loads and change of embedment depth due to 1D local scouring

Offshore wind turbine foundations are subjected to high lateral loads but insignificant vertical forces of the superstructure. A decrease in the embedment depth due to scouring can also alter the effect of vertical loads on the soil-structure interaction. Current design methods consider the vertical and lateral forces in design separately. This area also lacks studies featuring physical modeling that produce consistent conclusions. The present study employed centrifugal physical modeling to investigate the lateral behavior of offshore wind turbine monopiles under the simultaneous effects of vertical and lateral loads with a change in embedment depth caused by 1D local scour (D = diameter of pipe) in calcareous sand. The results showed that the vertical load of the superstructure increased the lateral strength of the monopile in the no-scour and local scour cases by about 3.5% and 6%, respectively. Improvements in the p-y curves along the embedment depth were noted at depths of less than twice the monopile diameter. Stress intensification was more significant under the scoured conditions because of the reduced embedment depth of the monopile. Overall, the vertical superstructure loads had little effect on the lateral performance of the monopiles.