Lateral Loading Conditions Research Articles

Effective Stress-Based Numerical Method for Predicting Large-Diameter Monopile Response to Various Lateral Cyclic Loadings

Extreme marine environmental cyclic loading significantly affects the serviceability of monopiles applied for the foundation of offshore wind turbines (OWTs). Existing research has primarily used p-y methods or total stress-based models to investigate the behavior of monopile–marine clay systems, overlooking the pore pressure development in subsea clay. Studies on the effective stress-based behavior of clay under various lateral cyclic loading conditions are limited. This paper presents an effective stress-based 3D finite element numerical method developed to predict key behaviors of pile–clay systems, including permanent pile rotation under cyclic loading, pile bending moment, and the evolution of pore pressure in subsea clay. The model is verified by contrasting the simulations results to centrifuge experimental results. Cyclic lateral loading is divided into average cyclic load and amplitude of cyclic load to investigate their impacts on the pile–clay system response. The research findings offer insights for the design of large-diameter monopiles under complex cyclic loading conditions.

Mechanism and prevention of coal bursts in gob-side roadway floor under thick and hard roof in the deep mining area of Ordos

The complex stress environment in deep roadways, often exacerbated by thick and hard strata, frequently precipitates coal bursts, posing significant safety hazards. This paper investigates the mechanisms and preventive methods for coal bursts in the gob-side roadway floor (GSRF) under thick and hard roof in the Ordos region, China. First, the stress-distributing characters of GSRF were analyzed then a stress calculation formula was derived. A mechanical model was developed to determine the critical stress for buckling failure of the roadway floor strata. Criteria for the bursting instability of GSRF were then established. The lateral static load from the adjacent gob, the advancing static load from the working face, and the disturbance load from overlying thick and hard roof fractures combine to transmit high loads and energy to the roadway floor via the “roof → rib → floor” pathway, causing increased stress concentration and energy accumulation. When the conditions satisfy the criteria for bursting instability, coal bursts can occur on the roadway floor. To mitigate dynamic load disturbances, the paper proposes roof regional fracturing and abrasive water jet axial roof cutting. Hydraulic reaming of gutters in the roadway ribs and deep hole blasting at the roadway bottom corners are offered to alleviate the static loads on the surrounding rock. The implementation of targeted prevention measures for dynamic and static loads effectively reduces coal bursts in GSRF. These findings offer an example of preventing and controlling coal bursts in other mines of the Ordos region with comparable geological conditions.

On the Influence of Different Infill Pattern Structures on the Crashworthiness Performance of 3D Printed Tubes Subjected to Lateral Loading Condition

On the Influence of Different Infill Pattern Structures on the Crashworthiness Performance of 3D Printed Tubes Subjected to Lateral Loading Condition

Advanced Predictive Structural Health Monitoring in High-Rise Buildings Using Recurrent Neural Networks

This study proposes a machine learning (ML) model to predict the displacement response of high-rise structures under various vertical and lateral loading conditions. The study combined finite element analysis (FEA), parametric modeling, and a multi-objective genetic algorithm to create a robust and diverse dataset of loading scenarios for developing a predictive ML model. The ML model was trained using a recurrent neural network (RNN) with Long Short-Term Memory (LSTM) layers. The developed model demonstrated high accuracy in predicting time series of vertical, lateral (X), and lateral (Y) displacements. The training and testing results showed Mean Squared Errors (MSE) of 0.1796 and 0.0033, respectively, with R2 values of 0.8416 and 0.9939. The model’s predictions differed by only 0.93% from the actual vertical displacement values and by 4.55% and 7.35% for lateral displacements in the Y and X directions, respectively. The results demonstrate the model’s high accuracy and generalization ability, making it a valuable tool for structural health monitoring (SHM) in high-rise buildings. This research highlights the potential of ML to provide real-time displacement predictions under various load conditions, offering practical applications for ensuring the structural integrity and safety of high-rise buildings, particularly in high-risk seismic areas.

Comparative analysis between continuous and discontinuous methods for the assessment of a cultural heritage structure

AbstractIn an era marked by the urgent need to ensure the safety of existing buildings according to current standards, evaluating the stability of masonry structures against hazard events has become a significant challenge. Despite the versatility and durability of masonry, structural assessments are hampered by factors such as limited information on material properties, irregular geometries, and ageing. To address this issue, numerous modelling techniques have been developed, supported by extensive scientific literature. However, significant factors related to the case study replication, such as the geometric complexity, the mechanical behaviour of masonry, the loading applications, contribute to the challenges associated with modelling procedures, including computational time, discretization procedures, and step incrementation. This paper critically discusses the most innovative modelling approaches. Specifically, it aims to compare the efficiency of the Distinct Element (discontinuous) Methods and the Finite Element (continuous) Method, both applied to the numerical simulation of a case study structure severely damaged by the 2016 Central Italy earthquake under lateral loading conditions. The continuous method is analysed using Midas FEA NX©, while the discontinuous methods are studied using 3DEC© and LMGC90© software, each with different contact conditions. Finally, the investigation highlights the main advantages and disadvantages of each method. In particular, the discontinuous method demonstrates reliability in accurately replicating failure patterns, whereas the continuous method allows for a faster model setup, making it suitable for preliminary studies on structural dynamics.

Analytical Study of the Structural Behavior of Hollow-Hole Anchors for Replacement of Bridge Bearings under Static Lateral Loads

Analytical Study of the Structural Behavior of Hollow-Hole Anchors for Replacement of Bridge Bearings under Static Lateral Loads

Experimental investigation of traditional Kath-Kuni wall system and traditional joints

In the Indian Himalayan region, the traditional vernacular construction system is a centuries-old system that is considered a seismic-resistant construction system. This practice is developed in the area over a period of time by the local communities and is never conventionally engineered. Hence, it is important to know about the behaviour of traditional construction systems and key features associated, under gravitational and lateral loading conditions. In the present research, experimental studies have been done on the full scale as well as scaled-down kath-kuni wall specimens, under push-over loading conditions, to characterize its overall behaviour, deformation and earthquake-resisting features. The failure of the kath-kuni wall was governed by friction capacity reduction followed by internal rotation in wooden layers. The kath-kuni system showed high ductile behaviour and the behaviour factor R was calculated as more than 5.4, and was compared with conventional brick masonry. The joints in the kath-kuni wall system have been identified and separate experimental studies, with varying member sizes, have been conducted to find out behaviour and capacity of these traditional joints upon loading. Analytical equations, to calculate capacity, have been proposed and compared with experimental results. The coefficient of friction was found to be varying in between 0.42–0.8 for different surfaces under constant overburden.

Seismic Performance of Unreinforced Masonry Walls with Various Retrofitting Methods

ABSTRACT This study proposed practical retrofitting methods to enhance the seismic performance of unreinforced masonry walls, utilizing textile-reinforced mortar (TRM) composites, glass fiber-reinforced polymer (GFRP) strips, and fiber-reinforced cementitious composites (FRCC). Retrofitting materials were applied at wall boundaries using the cast-in-place method with and without anchorage. Four masonry wall specimens, one control and three retrofitted, were fabricated and tested under lateral cyclic loading conditions to assess retrofitting efficiency. Various parameters were assessed, including hysteresis response, ductility, stiffness degradation, and energy dissipation capacity. The results indicated that TRM and FRCC retrofitting techniques exhibited an improvement in both the strength and deformation capacity. Among the retrofitting approaches, FRCC combined with steel reinforcement anchored to bottom beams showed superior performance Meanwhile, although exhibiting strength improvement, the ductility of the specimen retrofitted with FRP strips decreased post-peak due to severe splitting cracks. Lastly, an analytical strength model was proposed to predict lateral load-carrying capacity, demonstrating a reasonable correlation with test results. For the future application of the proposed retrofit methods, appropriate anchorage details for TRM and GFRP techniques are needed to be developed which could enhance deformation capacity in the post-peak stage of the retrofitted walls.

Deformation ability of steel inner sleeve T-joint in modular gymnasia based on 3D-DIC method

Substantial loads the roofs bear exert stringent performance standards on connecting joints in movable modular gymnasiums. Previously, we introduced a novel joint design, utilizing internal sleeves and bolts to integrate the upper and lower columns of modular units. To explore the actual deformation behavior and force distribution of this joint, this study employed a three-dimensional digital image correlation (3D-DIC) measurement method to visualize its full-field displacement and strain distribution. The reliability of the 3D-DIC results was confirmed through comparison with traditional measurement methods. Building upon this solid foundation, this study proceeds to assess the static performance of this innovative joint in two distinct directions, successfully revealing micro-deformation and local buckling phenomena undetectable to the naked eye. Notably, the quality of the welds connecting the beams and columns plays a pivotal role in ensuring the overall structural integrity of the joint. Under lateral loading conditions, the destructive behavior of the joints is primarily governed by material strength. Moment-rotation curves were plotted to delve further into the mechanical characteristics of the joint, revealing that the inner-sleeve T-joint exhibits the attributes of a rigid joint. Moreover, the primary damage modes observed in the specimens were fractures at the beam root or buckling of the column, with the joint area remaining intact. Consequently, this joint qualifies as a full-strength connection. These findings will deepen knowledge and understanding of this novel joint for designers.

Estimation of The Maximum Bending Moment on Pile Group Under One-Way Cyclic Loading in Sandy Soil

In fact, most civil engineering projects are subjected to cyclic loads. The sources of this load are usually seismic, wind, sea waves, and others. Model tests in sandy soil were performed to determine the maximum bending moment at which a pile group (2x2) would respond under one-way lateral cyclic loading. The group pile was made of aluminum piles that were installed in sandy soil with a 70% relative density and three-pile spacing of (3D, 5D, and 7D). The cyclic loads ratio (CLR) used are (0.6, 0,0,8, and 1.0) that is a result from average lateral static load. It can be concluded that an increase in group pile spacing can reduce the maximum bending moment by up to 92%. In addition, As the distance increases, the bending moment decreases, the front pile group provides a greater maximum bending moment than the back rows, as the maximum value in comparison reached 53%.

Analysis Seismic Behavior of Structures with Planar Imperfections: A Comprehensive Numerical Analysis

This paper presents a comprehensive approach to the seismic analysis and design of a tall hospital building, accounting for horizontal irregularities and employing equivalent static analysis (ESA) methodology. The study initiates with the collection of relevant site data and building specifications, including the identification and characterization of horizontal irregularities such as setbacks, mass distribution variations, and irregular floor plans. Equivalent static lateral loads are calculated based on applicable building codes and standards, taking into account the effects of horizontal irregularities on seismic response. Structural modeling and analysis are then conducted using sophisticated software to evaluate the building's behavior under seismic forces, considering the influence of irregularities on structural performance. Design criteria, encompassing drift limits, strength requirements, and detailing considerations for mitigating irregularity effects, are rigorously adhered to ensure compliance with safety regulations and performance objectives. The iterative process of evaluation and adjustment ensures optimal seismic performance and adherence to design criteria despite the presence of horizontal irregularities. Documentation of the analysis and design process, coupled with meticulous construction oversight, guarantees the implementation of a robust seismic design strategy tailored to the unique characteristics of the tall hospital building. Post-construction evaluations are carried out to validate predicted seismic performance, accounting for the influence of horizontal irregularities. Through collaborative efforts and adherence to best practices, the seismic design of the tall hospital building prioritizes safety and resilience, even in the face of horizontal irregularities, aiming to safeguard occupants and critical healthcare infrastructure during seismic events.

Numerical simulation of offshore monopiles with reinforcement in shallow soil layer

With the development of large-scale offshore wind turbines (OWTs), monopile foundations require larger diameter and greater embedded depth to satisfy the higher bearing requirements. Large-diameter monopiles for OWTs are mainly loaded horizontally, and the horizontal resistance provided by the shallow soil plays an important role in the loading of the monopile foundation. Therefore, shallow soil reinforcement (such as cement grouting and bio-grouting) is an effective method to improve the bearing capacity of the monopile. In this study, the lateral static loading mechanism of a shallow-layer reinforced monopile was investigated by finite element method (FEM). The effect of reinforcements with different stiffness values (elastic modulus), different strengths (cohesion and friction angle) and different reinforced ranges (width and depth) was analyzed on the lateral bearing capacity, deformations, soil resistances, and soil resistance per unit length to pile deflection (p-y) curves of monopiles. Based on the numerical results, an empirical formula was proposed for predicting the reinforcement coefficient of the bearing capacity. The effects of different reinforcement parameters on the distribution of soil resistance were analyzed, and the soil resistances obtained by FEM were compared with those from a theoretical formula. It was found that the resistance provided by the reinforced soil was clearly reduced at the interface with the unreinforced soil, and the resistance of the unreinforced soil was not significantly affected by the reinforced soil.

Experimental investigation of the mechanical performance of novel rigid connections in prestressed circular composite precast concrete columns under cyclic lateral loading

The present study introduces an advanced design of Prestressed Circular Composite Precast Concrete Columns (PCCPCCs), which have been applied in real-world structures, equipped with two novel rigid connection types (i.e., the reinforcing-cage connection and the welded-plate connection) to address existing challenges in the design, construction, and quality control of traditional precast concrete (PC) columns. Five full-scale specimens were experimented individually to assess the mechanical performance of PCCPCCs subjected to cyclic lateral loading and constant axial loading. The results indicate that the specimens exhibited no signs of collapse or loss in axial load capacity during the tests. Furthermore, all specimens met or exceeded the performance criteria set by relevant standards, such as GB50011-2010 and ACI 374.1-05, regarding drift ratio, moment capacity, energy dissipation, and ductility. It demonstrates that the novel design of PCCPCCs proposed in this study can be integrated into practical construction projects designed as lateral-force-resisting systems, such as moment-resisting frames and bridges, to accommodate diverse construction project requirements.

A Study on the Variations in Lateral Loading Imapcats Between Medium and High-rise Buildings Under Diverse Enviromental Conditions

-This thesis investigates the lateral loading effects on medium and high-rise buildings and compares their responses under different loading conditions. The study aims to provide insights into the behavior of these structures and aid in designing safer and more efficient buildings. The research methodology comprises analytical and numerical simulations of both medium and high-rise buildings subjected to various lateral loads. The analytical approach involves the use of hand calculations and mathematical models to determine the response of the building under different loading scenarios. The numerical simulations utilize computer software to model the structural behavior of the buildings and predict their response to lateral loads. The study focuses on four main lateral load types: wind loads, seismic loads. The loading conditions are applied to the buildings individually, and their responses are compared in terms of their lateral displacement, drift, and acceleration. The results show that both medium and high-rise buildings are susceptible to lateral loads, and their response depends on various factors such as building height, stiffness, and load duration. The lateral displacement of the high-rise building is more significant than the medium-rise building under all types of loading conditions. The results also show that the acceleration of the high-rise building is more significant under seismic loads than wind load. The study provides valuable insights into the behavior of medium and high-rise buildings under different lateral loading conditions. The findings of the study can be used to improve the design of these structures and enhance their resilience to lateral loads. The study recommends that designers should pay close attention to the building's lateral load resisting system and consider the impact of structural irregularities to ensure the building's safety and stability.

Effects of immediate loading directionality on the mechanical sensing protein PIEZO1 expression and early-stage healing process of peri-implant bone

BackgroundThe reduced treatment time of dental implants with immediate loading protocol is an appealing solution for dentists and patients. However, there remains a significant risk of early peri-implant bone response following the placement of immediately loaded implants, and limited information is available regarding loading directions and the associated in vivo characteristics of peri-implant bone during the early stages. This study aimed to investigate the effects of immediate loading directionality on the expression of mechanical sensing protein PIEZO1 and the healing process of peri-implant bone in the early stage.MethodsThirty-two implants were inserted into the goat iliac crest models with 10 N static lateral immediate loading applied, followed by histological, histomorphological, immunohistochemical, X-ray microscopy and energy dispersive X-ray spectroscopy evaluations conducted after 10 days.ResultsFrom evaluations at the cellular, tissue, and organ levels, it was observed that the expression of mechanical sensing protein PIEZO1 in peri-implant bone was significantly higher in the compressive side compared to the tensile side. This finding coincided with trends observed in interfacial bone extracellular matrix (ECM) contact percentage, bone mass, and new bone formation.ConclusionsThis study provides a novel insight into the immediate loading directionality as a potential influence factor for dental implant treatments by demonstrating differential effects on the mechanical sensing protein PIEZO1 expression and related early-stage healing processes of peri-implant bone. Immediate loading directions serve as potential therapeutic influence factors for peri-implant bone during its early healing stage.

EXPERIMENTAL STUDY ON THE STRUCTURAL BEHAVIOUR OF RECYCLED PLASTIC ONE STORY HOUSES

Recycling plastic materials may constitute a relief measure to the global plastic problem. Several companies are now producing recycled plastic for use as construction material in single-story houses. One commercially available layout involves assembling Recycled Plastic Lumber units in a running bond pattern, forming panels confined by horizontal and vertical tie elements joined through bolted steel plate connections. As production of houses is industrialized, the architectural layouts are standardized according to specific distribution and dimensions. This paper presents the findings of an experimental program aimed to characterize the seismic behavior and properties of a one-story house model. To facilitate practical application, the model is referred here as Architectural Standard Model (ASM). The objectives of the test campaign were to investigate the structural behavior of the constituting members and assemblies, and the response of structural walls to cyclic static lateral loads. Three natural scale wall specimens were tested in-plane and two out of plane. Results of natural scale cyclic loading tests demonstrated that structural system of the ASM can perform acceptably safely under high seismic loads if it is adequately fixed to the foundation. The results showed that out of plane loading was the critical pattern and behaved like a unidirectional plate that transmitted load to the columns. In plane observed behavior exhibited predominating rocking component, which suggests considering an evaluation of the system's response using dynamic methods.

Lubrication Modeling of the Reciprocating Piston with High Lateral Load and Various Conditions in a Swash Plate-Type Piston Pump

Most asymmetrical lateral forces occur in the reciprocating piston mechanism, which is widely applied as a major component of power equipment. When this lateral force greatly acts on the piston, it comes into contact with the cylinder. To prevent this negative phenomenon, lubrication characteristic evaluation and control technology are necessary. In this study, a boundary lubrication model considering the elastic deformation of the contact surface was adopted to perform a lubrication analysis of a piston hydraulic pump widely used in the aviation and plant industries. The piston/cylinder mechanism was analyzed in terms of contact force, characteristic thickness, and power loss while varying various design and operating parameters (friction coefficient, clearance, profiling shape, operating speed, and pressure). In the overall bearing capacity to withstand the tilt of the piston, the bearing capacity ratio due to contact at the interface increased more steeply than the bearing capacity ratio in the fluid lubrication area. Profiling of the piston head played a positive role in reducing power loss but also increased piston tilt. This trend appeared more clearly as the head profiling degree of processing Increased. Lastly, the effects of variable operating speed and pressure were examined. High operating speed caused low contact force, and high operating pressure caused high contact force. Through this study, it was possible to predict the lubrication performance and power loss of reciprocating piston pumps used in the field more realistically through appropriate boundary lubrication modeling.

Effect of Sloping Ground on the Pile Behaviour Under Varying Static Lateral Loads

Effect of Sloping Ground on the Pile Behaviour Under Varying Static Lateral Loads

Response of vertical and batter piles under combined lateral and vertical loading conditions in sandy soil

Response of vertical and batter piles under combined lateral and vertical loading conditions in sandy soil

Multi-objective optimization for snap-through response of spherical shell panels

Composite spherical shell panels are commonly used for the lightweight design of thin-walled structures in the structure, architecture, aerospace engineering. Depending on the shell panel length, thickness, curvature, and stacking sequence, the load-deflection response under lateral load can be either a completely stable equilibrium path or an unstable snap-through path. In this work, the response of simply supported cross-ply composite spherical shell panels subjected to lateral static loads is studied and optimized. The spherical shell exhibiting snap-through response is optimized to (a) maximize the load required to initiate snap-through and (b) minimize the unstable region. Meanwhile, the spherical shell exhibiting continuous response is optimized to (a) maximize the softening-hardening load and (b) minimize the shell weight. The decision variables for both constraint multi-objective optimization (CMOO) problems include layup sequence, thickness, and the radius of curvature to side length ratio. The nonlinear governing equations are derived based on Kirchhoff–Love hypotheses for thin shells and Hamilton's principle. A novel semi-analytical method is presented based on Bernstein polynomials combined with a fast iterative approach to compute the objective features of the responses. Benefiting from the high efficiency and robustness of the proposed approach, the CMOO problems are solved by the metaheuristic Multi-Objective Artificial Hummingbird Algorithm (MOAHA). Composite spherical shell panels with various geometry and lamination configurations are considered to validate the performance of the proposed method. The optimization of geometric parameters (shell curvature and thickness) in addition to the staking sequence provide a high degree of tailoring of the shell performance to meet various objectives. These parameters are taken as design variables that must be optimized to achieve some objectives and satisfy arbitrary nonlinear constraints.