Building Vibration Research Articles

Multi-objective optimal design of Tuned Mass Damper Inerter for base isolated structures

The BIS-TMDI is a hybrid control strategy that significantly reduces the seismic response of structures compared to conventional BIS through proper tuning, albeit with the trade-off of increased control forces exerted by the TMDI on the host building structure. However, these potentially significant forces are generally not considered in current TMDI tuning approaches. In this paper, a multi-objective optimization design method is herein developed to determine the compromise between the competing objectives of suppressing earthquake-induced vibrations in buildings and avoiding the generation of excessive control forces of TMDI. The study shows that under non-stationary excitations, the average control force of the TMDI system can be reduced by 16% compared to single optimization constraint, with a maximum reduction of up to 25%. Finally, the optimization design methods of this paper are applied to an 8-story frame as a validation case.

Influence of Spatially Varied Soil Property on Train-Induced Soil-to-Column Vibration Transmission

The proximity of residential areas to traffic corridors has raised concerns among researchers regarding train-induced vibrations. Experimental studies have consistently shown variations in train-induced vibrations, which can be attributed to uncertainties and randomness in both the vibration source and propagation path. This study aims to investigate the influence factors and quantify their contributions to train-induced vibration variations through a comprehensive field measurement campaign and numerical simulations using random finite element models. During the field measurements, vibrations were recorded at the ground surface and the column base for a total of 53 passbys of the same type of metro train on parallel rail lines. Variations in train-induced vibrations caused by the source-to-receiver distance and spatially varied soil properties were analyzed and compared. Specifically, the investigation focused on the spatial variation of soil properties including elastic modulus, density and damping ratio in the topsoil and the second layer of clay, while simultaneously considering the influence of spatial variations of all three soil properties on the transmission of train-induced vibrations from the surface soil to the structural columns. Understanding these variations is crucial for the probabilistic assessment of building serviceability during train passbys. The findings of this research provide valuable insights for probabilistic prediction and evaluation of building vibration comfort.

Application of pole allocation to optimize passive viscous dampers represented by the Maxwell model

The Maxwell model is used to understand the realistic effectiveness of vibration reduction in the building structures. The model consists of a dashpot and spring in series. The dashpot and spring represent a viscous damper and joint between the damper and the structural frame, respectively. However, few studies have investigated the optimal damper capacity and the corresponding spring stiffness in the practical parameter ranges. Additionally, the optimal damper derived using the fixed-point theory has no relationships with that derived via pole allocation. Therefore, in this study, to examine the effects of the joint spring, the pole allocation method was used to design a structural system wherein the Maxwell model was incorporated into a single-degree-of-freedom damped model. We introduced a closed-form expression, which explicitly described the relationships between the target structural damping ratio, damper capacity, and joint spring. The Maxwell model constrained the control effectiveness using damper parameters and simultaneously suggested an optimal and realistic joint spring for the damper. Pole allocation was also applied to a multi-degree-of-freedom (M-DOF) damped structural system employing multiple Maxwell models. The newly proposed optimized joint spring could easily control the additional damping effect on the M-DOF system. The Maxwell model can be optimized almost manually. The scheme is more useful in the preliminary design stage than the previous numerical optimizations. This study extended the mathematical equation governing the building vibrations to the Maxwell model. The extended equation served as a unified description for considering structural passive control.

A variable damping viscous damper for control of buildings under wind loading

High-rise buildings are susceptible to low-frequency vibrations induced by wind loading, and the traditional constant damping viscous damper (CDVD) falls short in effectively suppressing vibrations of high-rise buildings under wind loadings because of its constant damping coefficient. To address this, a novel variable damping viscous damper (VDVD) is first designed and fabricated. The characterization tests were conducted to evaluate the variable damping characteristics under different velocities. The control performance of the VDVD in high-rise buildings under wind loadings with varying wind pressures is simulated and analysed, as comparisons with CDVD. The test results show that the damping coefficient of the VDVD increases with the input velocity. Furthermore, it exhibits the capability to achieve both constant and variable damping through the adjustment of the pre-pressure force in the spring. Compared with cases using CDVD, the VDVD demonstrates a significantly greater reduction in structural response, with cumulative dissipated energy ratios ranging from 1.0 to 3.14 as wind pressure increases. The VDVD offers excellent potential for various engineering applications in terms of new concepts and new devices for vibration control and mitigation induced by wind loadings.

Research on Human Exposure to Transport-Induced Vibration in Buildings

The analysis of human perception of vibrations in buildings is a critical aspect of structural engineering, particularly as urbanization intensifies and the proximity of vibration sources to buildings increases. This paper addresses the frequent errors in the assessment and diagnosis of the impact of vibrations on building occupants. Despite stringent standards and detailed methodologies, misinterpretations and incorrect implementations of these guidelines are common, leading to flawed diagnostic studies. These errors often stem from the misuse of measurement equipment, inappropriate selection of measurement points, and a general lack of comprehensive education on vibration analysis. National guidelines, although largely based on ISO standards, vary significantly, contributing to inconsistent practices across Europe. The dominant sources of urban vibrations include vehicle traffic, particularly heavy trucks and rail vehicles, which significantly impact both building structures and human comfort. This paper reviews the methodologies for measuring and interpreting vibrations, emphasizing the importance of correct sensor placement and data analysis. It highlights the necessity of integrating vibrational comfort into building design, considering both external and internal vibration sources. The study also explores the effectiveness of different evaluation methods, such as the RMS and VDV methods, and the impact of various weighting functions on the analysis results. The findings underscore the need for improved education and standardization in the field to ensure accurate assessments and enhance the vibrational comfort of building occupants.

Method for Predicting Environmental Vibration Impact of Existing Subway Lines and Its Practical Application

To predict accurately the impact of track vibrations caused by subway trains on adjacent buildings and address the problem of their excessive dynamic response, a method for predicting the environmental vibration impact of existing subway lines is proposed in this paper. A coupled numerical dynamical model of the train/track/tunnel system is established using the multi-scale method. Using field-measured soil vibration data, empirical formulas for soil frequency and material damping coefficient are calibrated. By combining the numerical model and the empirical formulas, buildings’ indoor vibrations and noise level can be assessed. At the same time, a solution to the problem of excessive vibration of buildings along a subway line is also proposed that optimizes the track fastener parameters. Field tests verified the accuracy of the prediction method and the effectiveness of the optimized track parameters. These research results provide a reference for predicting the vibration of buildings along subway lines and using the proposed preventive solutions.

FEM simulation of vibrations in building: from volume to shell elements

The problem of vibrations in buildings situated in the proximity of railway tracks is a major concern for the resident's comfort. More and more studies focus on this problem using FEM models, with shell elements for the building's walls and floors. However, the validity of this simplification is never fully justified, and it raises questions concerning the dimensions to apply to the model. The model of a building made of 3D elastic elements is compared to its simplified version made of shell elements. Three geometries with different dimensions are tested to find the one closer to the reference model. Different shell offsets are also tested. The results show great differences of floor vibration levels, mostly for high frequencies, depending on the dimensions of the geometry and the offset. The shell configuration with the closest results to the reference model is discussed.

Optimization-Based Vibration Control Analysis of Dampers in High-Rise Building

Tuned mass dampers (TMDs) are a useful control of vibrations for tall buildings and can be considered equal to burdens such as breezes and earthquakes. The better limits for TMD are to reduce the earthquake vibrations of tall buildings including soil–structure interaction (SSI) influences. This study proposes the multi-objective Black Widow Optimization (BWO) with Elman neural network (ENN) computation that is brought on to find the optimal limits of TMD. Considering that this proposed model analyzed the mass, stiffness, and damping ratio of TMD to get the maximum accelerations and displacement of 40 story building model, from the execution results, starting from this proposed BWO–Elman model to the expected methodology, the most outrageous TMD limits are better, likewise, the reduction of acceleration and displacement are 25% and 19.86% in the proposed study. This study assists the researchers with a better understanding of earthquake vibration and leads the fashioners to achieve superior TMD for tall designs. The impact of vibration control on the displacements and accelerations of both controlled and uncontrolled buildings is investigated in this work. It uses a MATLAB software technique to analyze their modal replies, moreover, this proposed optimal TMD model is compared with conventional techniques by acceleration and stiffness parameters.

Predicting the Influence of Vibration from Trains in the Throat Area of a Metro Depot on Over-Track Buildings

Urban land resources are scarce in China. To utilize land effectively and economically, many cities are developing over-track buildings above metro depots. The vibration from the entrance and exit lines of metro depots under an over-track platform would significantly impact over-track buildings. To study the influence of train vibration in the throat area of a metro depot on over-track buildings, a simulation model was established using a finite element method. The reasonability of the simulation method and parameter settings was verified through comparing the vibration simulation results with vibration test results in the throat area of a metro depot. Furthermore, the impact of parameters of over-track platform and building on indoor vibration induced by a train was quantitatively studied. According to simulation results, a prediction model was developed to predict the impact of train vibration on over-track buildings in metro depots. From the perspective of architectural planning and design, this study provides a theoretical and technical basis for the prevention and control of indoor vibrations in over-track buildings of urban metro depots.

Measurement and analysis of vibration responses due to subway transit in residential areas

The issue of building vibrations caused by subway operations has become increasingly prominent, significantly impacting residents' daily lives. This study investigates the vibration response of a residential area when the subway passing through, which involved the vibrations of the free field, the basement, and the nearby buildings. In addition, numerical simulation of building vibration by Etabs software was discussed. The free field vibration above the shield tunnel diminishes rapidly in the vertical track direction as the horizontal distance increases. However, the influence range of subway induced vibrations significantly expands when a basement is built adjacent to the subway. Data on building vibrations revealed the distribution of vibrations along the vertical direction and the vertical vibration amplification at the slab center due to local resonance. Interestingly, isolation designed for seismic loads also offers some benefits in reducing vertical vibrations. The numerical simulation results of the vibration response at the shear wall bottom show a certain degree of consistency with the actual measured results, but the attenuation of the vibration is faster, which may underestimate the vibration response of the building. The findings of this study provide valuable insights for understanding the impact of subway operations on surrounding buildings, optimizing subway and structural spatial layouts, and designing for vertical vibration control.

Investigation on vortex-induced vibrations of square-sectioned high-rise buildings with various structural eccentricities

Structural eccentricities in a high-rise building can induce strong modal coupling, which therefore influences vortex-induced vibration (VIV) responses of the building and consequently affects human comfort within the building. This study investigates the VIV behaviour of square-sectioned high-rise buildings with different structural eccentricities, using both wind tunnel test and computational fluid dynamics (CFD) technique. Firstly, a novel method for constructing the multi-degree-of-freedom (MDOF) aeroelastic model of a high-rise building with specified structural eccentricities is introduced in detail. Seven MDOF aeroelastic models with different structural eccentricities are constructed. Wind tunnel test is then conducted to examine VIV responses of these high-rise building models. Effects of eccentricity ratio and direction on the models’ VIV responses are comprehensively investigated. In addition, CFD simulation is conducted to elucidate the aerodynamic mechanism of VIV responses of high-rise buildings with structural eccentricities. Results reveal that the direction of structural eccentricity influences the reattachment of vortex shedding over the building, which in turn affects the lift and, consequently, the building’ VIV responses. The maximum VIV response of the building models exhibits a negative correlation with the windward eccentricity ratio, while a positive correlation with the leeward eccentricity ratio. Results from CFD simulation demonstrate that the structural eccentricity tends to broaden the wake downstream, resulting in a reduction in the building’s vortex shedding frequency and, consequently, the Strouhal number. Findings of the present study can enhance the understanding of VIV behaviours of high-rise buildings with structural eccentricities, providing valuable insights for the wind design of such structures.

A hybrid methodology for the prediction of subway train-induced building vibrations based on the ground surface response

The numerical simulation and theoretical methods for the subway train-induced vibration of the shallow foundation buildings often suffer from high cost, unstable prediction accuracy, and lack of clarity of important parameters. Therefore, a hybrid prediction method based on the Z-vibration level at the ground surface was proposed to rapidly obtain the vibration characteristics of the shallow foundation building adjacent to the subway. The numerical simulation was first used to obtain the subway train-induced vibration of the shallow foundation building under different working conditions. Then, a hybrid model was established and retrained by combining the field measurement data of the soil and building vibration along the subway line. Finally, the prediction accuracy of the hybrid model with different numbers of measurement points as input layers was explored, and a case study was performed. The results show that the most noticeable effect on subway train-induced building vibration is the length of the building span among the shallow foundation building parameters. Three measurement points of the Z-vibration level at the ground surface are suggested as the training set data for the input layer of the hybrid model in consideration of computational efficiency and accuracy. The prediction accuracy of the hybrid model gradually increases as the number of data sets increases, and the fully trained hybrid model performs more stable across the frequency range compared to the traditional model, with the majority of its predictions in the 90% confidence interval, which provides the possibility of simplifying the analysis and fast prediction of subway train-induced building vibration.

Research on Vibration and Secondary Noise Characteristics of Sensitive Buildings Along Metro Lines Induced by Metro Operation

With the rapid development of urban rail transit, the environmental vibration and secondary noise induced by metro train operation have become increasingly serious, posing stricter requirements on the vibration and secondary noise of sensitive building office (SBO) and sensitive building school (SBS). To predict and control the vibrations and secondary noise in sensitive buildings along the metro line induced by metro train operations. A prediction method for the vibration and secondary noise of sensitive buildings along the metro line during metro train operation has been proposed. The sub-model of train-track system coupled dynamics and the sub-model of track-tunnel-soil-building system dynamics are included. The influence of metro train operation on the vibration and secondary noise of SBO and SBS is studied. The influence of the distance between the metro line and the building on the vibration and secondary noise of the sensitive building is discussed, and an effective control scheme of vibration and secondary noise is proposed. Results show that the vibration frequencies of the SBS and the SBO caused by the metro train operation are concentrated at about 8[Formula: see text]Hz and 63[Formula: see text]Hz. The vibration below the second floor of SBO caused by the metro train operation exceeds the limit, and the secondary noise below the third floor of SBS exceeds the limit. The secondary noise inside the building of each floor of SBO exceeded the limit. Using secondary noise to evaluate the environmental impact of metro train operations is more stringent than relying solely on vibration assessments. secondary noise is recommended in engineering to assess the impact of metro train operation on sensitive buildings along line. Combined with vibration, secondary noise and construction requirements, SBS and SBO are recommended to be no less than 72[Formula: see text]m and 74[Formula: see text]m away from the metro line, respectively.

Vibration transfer from underground train to multi-story building: Modelling and validation with in-situ test data

Excessive underground train-induced vibration becomes a serious environmental problem in cities. To investigate the vibration transfer from an underground train to a building nearby, an explicit-integration time-domain, three-dimensional finite element model is developed. The underground train, track, tunnel, soil layers and a typical multi-story building nearby are all fully coupled in this model. The complex geometries involving the track components and the building are all modelled in detail, which makes the simulation of vibration transfer more realistic from the underground train to the building. The model is validated with in-situ tests data and good agreements have been achieved between the numerical results and the experimental results both in time domain and frequency domain. The proposed model is applied to investigate the vibration transfer along the floors in the building and the influences of the soil stiffness on the vibration characteristics of the track-tunnel-soil-building system. It is found that the building vibration induced by an underground train is dominant at the frequency determined by the P2 resonance and influenced by the vibration modes of the building. The vertical vibration in the building decreases in a fluctuant pattern from the foundation to the top floor due to loss of high frequency contents and local modes. The vibration levels in different rooms at a same floor can be different due to the different local stiffness. A room with larger space thus smaller local stiffness usually has higher vibration level. Softer soil layers make the tunnel lining and the building have more low frequency vibration. The influence of the soil stiffness on the amplification scale along the floors of the building is found to be nonlinear and frequency-dependent, which needs to be further investigated.

Monitoring of ground and building vibrations caused by train wheel defects

This paper describes a study performed on train wheel defects and their effect on rail vibrations. The paper describes a test setup allowing the researchers to capture ground vibrations at the desired level of detail to prove to what extend wheel quality influences ground vibration levels and associated nuisance to people. The analysis of the measurement signals shows that the individual axles of a passing train can be detected excellently with the signal from the axle detection and the vibration sensors. The signals from various sensors in the measurement setup are synchronized with high time accuracy, making it possible to overlay the time interval of an axis passage over the signal from the vibration measurements. This makes it possible to track vibrations at bogie and axle level. The distance of measurement points from the track is ultimately the determining factor for the extent to which vibrations are dominated by an axle, a bogie, a wagon or the entire train. In addition, direct wheel roundness measurements have been performed for trains that appear to have defect wheels based on ground vibration data. With the track based measurements, the ground vibration measurements and the direct wheel measurements an unique data set has been generated, allowing for an evaluation of the importance of defect train wheel from the perspective of vibrations nuisance to the environment. Relations of measured vibrations to other parameters, both rolling stock related and environmental parameters were investigated based on the generated set of data. The analysis on the data reveals interesting relations between train wheel parameters and ground vibrations, which are discussed in this paper.

Derivation and Application of Analytical Coupling Loss Coefficient by Transfer Function in Soil–Building Vibration

Vibrations generated by railways may undergo amplification or reduction while traversing the foundations, floors, and spans of adjacent structures. This fluctuation in the vibration intensity, identified as a building’s coupling loss, is commonly considered in vibration forecasts through the utilization of universal frequency-independent adjustment parameters. This article employs a theoretical analytical approach to investigate the propagation characteristics of Rayleigh waves in elastic foundation soil, as well as the variations at the contact surface of buildings’ foundations. Analytical expressions for the coupling loss coefficient are derived to explore the displacement transfer relationship in the soil–structure interaction. To accurately and efficiently analyze the proposed buildings and site, the entire vibration propagation system is decoupled into substructure systems for independent analytical calculations. Theoretical analytical methods are utilized to obtain the displacement transfer functions between the soil and the structures through the refraction and transmission of waves. From a theoretical perspective, a thorough understanding of the interaction between soil and buildings is achieved. The influence of various variables related to railways and foundations on the building responses is analyzed. By comparing with measured data, the correctness of the analytical form of the coupling loss coefficient is validated, filling a gap in the literature due to the lack of analytical research on displacement transfer losses in soil–structure interactions.

Exploring building vibration dynamics in the wake of the Chi-Chi earthquake: implications for natural hazard preparedness

Exploring building vibration dynamics in the wake of the Chi-Chi earthquake: implications for natural hazard preparedness

Simple soil-structure interaction model for wind-induced vibrations in high-rise buildings

Simple soil-structure interaction model for wind-induced vibrations in high-rise buildings

Effects of wind-induced vibrations in tall buildings on cognitive work performance, comfort, and wellbeing of the occupants

Effects of wind-induced vibrations in tall buildings on cognitive work performance, comfort, and wellbeing of the occupants

Effects of wind-induced vibrations in tall buildings on human balance and risk of falls

Effects of wind-induced vibrations in tall buildings on human balance and risk of falls