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The complex dynamic behavior brings challenges for investigating the ground vibration induced by trains passing through bridges, in which accurate modelling and a large amount of field data are required. To better understand and predict the ground vibration induced by high-speed trains passing through bridges, it is necessary to collect more field test data as well as to develop more accurate models and computational methods. In this study, a two-dimensional (2D) wheel-rail-bridge model was first constructed to determine the forces on the bridge pier, and these forces were then applied to the pier-ground finite element model to capture the ground vibration response. The simulated RMS acceleration and magnitude of acceleration were in good agreement with the field measured results, and the errors were within the acceptable range, which validated the effectiveness of the two-step method proposed in this study. The ground vibration response under various soil conditions was analyzed with the validated numerical model. The proposed method provides a reference for the prediction of ground vibration induced by high-speed trains passing through bridges and for the environmental protection. [ABSTRACT FROM AUTHOR]

Rockfill columns, also known as stone columns, were installed in a riverbank for slope stabilization measures. The goal of this fieldwork was to prevent slope instability of the riverbank while protecting an in-service aqueduct buried in the riverbank. At this site, rockfill columns were installed with the aid of steel casings (sleeves), which were later removed with a vibrodriver. Peak particle velocities were determined at select locations to monitor the ground vibrations during installation of rockfill columns and during extraction of the steel casings. Instrumentation and monitoring were implemented because there was uncertainty about the potential for structural damage to the nearby aqueduct due to ground vibrations during the stabilization works. In this case study, numerical modeling, calibrated versus field measurements in the ground and on the aqueduct, was used to simulate the ground vibrations due to the installation of three rockfill columns close to the aqueduct. Once calibrated, the numerical models were used to evaluate the effects of vibrations in terms of particle velocities in the ground, displacements of the aqueduct, and frequency spectra on the aqueduct walls. The numerical results showed that the highest particle velocities on the aqueduct were from the rockfill columns that had the steel casings located in the same soil layer as the aqueduct. Based solely on the response in terms of particle velocity, damage to the aqueduct is unlikely. However, the numerical results also showed that the aqueduct moves slightly, both vertically and laterally due to the vibration generated while removing the steel casings; and the frequency range of the waves in the ground are within the natural frequency of the soil, which could impose additional movement to the aqueduct if allowed to move freely with the soil. Numerical results and field data also show that even pulling the steel casings without vibration generated propagation of waves in the ground. [ABSTRACT FROM AUTHOR]

With the development of urban rail transportation, the environmental vibration problem caused by the running of metro vehicles has received attention. In order to reduce ground vibration near buildings caused by metro vehicles running on viaducts, this paper establishes the train–track–viaduct rigid–flexible coupling dynamics model and pier–soil–building finite element model and carries out the simulation calculation and analysis of ground vibration. The influence of train speed and fastener stiffness on ground vibration is explored, and the vibration reduction effect of the track vibration reduction pad and continuous support vibration reduction structure is studied. The results show that the ground vibration near the building caused by the train running on the viaduct decreases with the reduction in speed, when the speed is reduced to 40 km/h, the vibration attenuation is slower as the speed continues to be reduced; the reduction in the vertical stiffness of fasteners can reduce ground vibration; the arrangement of the vibration damping pad can effectively reduce ground vibration, and after installing a vibration damping pad, 0–23 Hz and 50–80 Hz ground vibration speeds are effectively suppressed. In order to meet the environmental requirements for ground vibration, the vehicle speed can be reduced to less than 35 km/h or vibration damping mats can be installed. [ABSTRACT FROM AUTHOR]

In order to analyze the ground vibration responses induced by the dynamic loads in a tunnel, this paper proposes a new simplified tunnel–soil model. Specifically, based on the basic theory of the thin-layer method (TLM), the basic solution of three-dimensional layered foundation soil displacement was derived in the cylindrical coordinate system. The perfectly matched layer (PML) boundary condition was applied to the TLM. Subsequently, a tunnel–soil dynamic interaction analysis model was established using the volume method (VM) in conjunction with the TLM-PML method. The displacement frequency response function of the foundation soil around the tunnel foundation was derived. Finally, a ground vibration test under an impact load in a tunnel was carried out. The test and calculated results were compared. The comparison results show that the ground vibration acceleration response values within 25 m from the load are similar. Compared with the test results, the theoretical calculation results exhibit a decreasing trend in the range of 40–80 Hz between 25 and 60 m, with the maximum reduction being approximately one order of magnitude. In addition, the experimental comparison demonstrates that the model can be used to analyze the ground vibrations caused by underground loads. [ABSTRACT FROM AUTHOR]

Ground vibration is one of the detrimental effects associated with blasting that can damage the surrounding environment and nearby structures. In the Gol-Gohar mine in Sirjan, due to the surface expansion, the distance between the structures and the blasting blocks has decreased, leading to vibrations reaching the processing plant complex. These vibrations, by triggering sensors installed on the mills, cause power outages in the circuit, thereby increasing production costs. One solution to mitigate the waves reaching the processing plant complex is to excavate trenches along the wave path. These trenches, by creating conditions like a free surface and reflecting the waves, reduce the transferred wave energy and can prevent unnecessary shutdowns of the concentration circuit due to increased vibration amplitudes. In this study, using the discrete element software UDEC, the results of a field blasting operation were first validated, and based on the validated model, the impact of trench excavation on the propagation of blast waves was analyzed. Ultimately, the optimal dimensions of the trench, which maximizes energy absorption, were determined. According to the numerical analysis results, the excavated trench on each side of the structure should be more than 2m longer and excavated at distances greater than 3m from the structure. Meanwhile, the thickness (width of the trench) had no significant effect on wave attenuation. This trench can reflect approximately 60% of the blast waves.

The ground vibration caused by the operation of high-speed trains has become a key challenge in the development of high-speed railways. In order to study the train-induced ground vibration affected by geotechnical heterogeneity, an efficient frequency–wave-number method coupled with the random variable theory model is proposed to quickly obtain the numerical results without losing accuracy. The track is regarded as a composite Euler–Bernoulli beam resting on the layered ground, and the spatial heterogeneity of the ground soil is considered. The ground dynamic characteristics of an elastic, layered, non-uniform foundation are investigated, and numerical results at three typical train speeds are reported based on the developed Fortran computer programs. The results show that as the soil homogeneity coefficient increases, the peak acceleration continuously decreases in the transonic case, while it gradually increases in the supersonic case, and the ground acceleration spectrum at a far distance obviously decreases; the maximum acceleration occurs at the track edge, and a local rebound in vibration attenuation occurs in the supersonic case. [ABSTRACT FROM AUTHOR]

High-speed train operation may cause vibration near track facilities and propagate far through the ground, affecting people's lives, work, and normal use of precision instruments in an urban environment. An efficient numerical method is proposed to calculate the non-uniform ground vibration under a moving high-speed railway load. The theory of stochastic variables is used to describe the soil spatial variability of the non-uniform layered elastic ground, and the coupled 2.5D random finite element method (FEM) is proposed to reduce the computational cost without losing accuracy. Vibration propagation and attenuation of the non-uniform layered ground are investigated and the effect of train speed and soil non-homogeneity are analyzed. Results show that (1) at cross speed and high speed, the homogeneity coefficient of the layered ground has the most important influence on the ground vibration amplitude; (2) the upward acceleration is much larger than the downward acceleration at most speeds, and at cross speed and high speed, the acceleration amplitude decreases with the increase in the homogeneity coefficient; (3) as train speed increases from 60 m/s to 130 m/s, the influencing range of the homogeneity coefficient increases to 10 m from 2 m; and (4) the phenomenon of an in increase in local rebound can be observed in the velocity and acceleration attenuation curve at cross speed when the ground soil has a weaker homogeneity. [ABSTRACT FROM AUTHOR]

Environmental considerations are an important aspect of construction activities, such as the impact of construction vibrations at project sites and in nearby properties. There are limited studies to investigate the impact of vibration from ground improvement construction and how underground utilities can be protected from vibration damage. This research is aimed at developing empirical formulations that can be used to predict ground particle velocities near buried structures. This will allow engineers to minimize potential vibratory damage to buried structures. In this study, ground vibrations are produced by the installation of rockfill columns, a ground improvement technique to stabilize riverbanks. Installation of rockfill columns was done near a buried aqueduct. So, there is a concern that this aqueduct can be damaged by ground vibrations. Finite-element analysis was done to provide information on ground vibrations caused by the installation of rockfill columns. The finite-element models were calibrated with particle velocities measured at the construction site. Results showed that the particle velocities obtained in the numerical models correlated well with the measured particle velocities and those reported in the literature (although from different sources of vibrations). Empirical relationships are proposed between ground vibrations and their impacts on nearby buried structures. Limiting ground vibration on structures near construction sites is a challenging task. Even though most guidelines use peak particle velocity (PPV) as the limiting parameter, there is no consensus as to which limiting values to use. Ideally, project-specific values could be estimated with predicting equations. Estimation of the vibratory impact from the installation of rockfill columns in the ground and their impact on buried structures is limited in the literature. This is due to the lack of data to validate prediction methods. As is shown in this paper, numerical results in this research reasonably agree with field PPVs reported in the literature. Therefore, empirically based predictions for the installation of rockfill columns, for the removal of steel casings, and for the vibratory impact of ground vibrations on buried structures for 5%, 50%, and 95% exceedances are proposed in this study. It is recommended that the proposed empirically based predictors be used as a preliminary evaluation tool, preceding numerical simulations to predict expected ground vibration in terms of PPV. It is understood that when the field data are obtained in the near field but prediction is for far field, the predictions tend to be conservative. On the other hand, prediction for the near-field response based on data from the far field is inappropriate and should be used with caution. In the field, well-planned instrumentation and monitoring would help protect buried structures from potential damage from ground vibrations, which was done in the case study presented in this paper. [ABSTRACT FROM AUTHOR]

Underwater drilling and blasting techniques have been developed to overcome the challenges posed by various subaquatic operations, including marine construction, oil and gas exploration, and underwater mining, demolition, dredging and excavation, seismic surveys and marine research. The drilling operation is followed by underwater blasting, which involves the creation of boreholes in submerged surfaces, such as sea beds or riverbeds. Specialized drilling equipment is utilized, which can operate in aquatic environments. To ensure efficient and reliable performance, the drilling equipment is designed to withstand the pressures and corrosive nature of seawater. Once the desired depth is reached, underwater blasting is utilized to break the rock or seabed. The primary objective of blasting is to loosen the substrate and create a cavity for subsequent operations. Safety is a crucial factor in underwater drilling and blasting operations. To safeguard personnel involved and prevent accidents during drilling and blasting activities, strict safety measures are implemented. In addition to human safety, precautions are taken to minimize the environmental impacts of underwater drilling and blasting, including measures to prevent pollution, protect marine life, and preserve the underwater ecosystem. In this article, the core elements of underwater drilling and blasting operations are outlined. Despite notable progress in this domain, the paper highlights the enduring constraints and obstacles, underscoring the need for continued investigation and understanding. [ABSTRACT FROM AUTHOR]

To deal with the issues of high computational cost and prediction uncertainty of numerical models in train-induced ground-borne vibration prediction, a prediction method based on transfer learning is proposed in this study. In this method, the vehicle–track-coupled analytical model and three-dimensional finite element model are first used to calculate the train-induced ground vibration under various condition variables, and these data were used as training samples to pre-train the deep neural network models. Numerous train-induced ground vibration experiments were then conducted along the metro lines in Beijing, and those measured vibration data were used to fine-tune the pre-trained deep neural network model with the transfer learning strategy. A random variable obeying a Gaussian distribution is assumed over the predicted vibration acceleration levels to model the randomness of train-induced vibration, and the parameters of this distribution were determined by the statistical results of vibration monitoring data in the metro tunnels. The fully trained model could complete the prediction of train-induced ground vibration in seconds. Finally, a case study was carried out, by comparing the probabilistic prediction results with the statistical results of the field measurements, and the feasibility and the improvement of the proposed method were demonstrated. [ABSTRACT FROM AUTHOR]

This study focuses on addressing the complexity inherent in various amplitude components of blast-induced ground vibration (BIGV), encompassing vertical, radial, transversal, and the vectoral sum of PPVs of particle velocity. It takes into account their nonlinearity across diverse quarry environments, and aims to present an enhanced nonlinear intelligent system for accurate prediction of these components. Multiple artificial intelligence models were explored and developed for this purpose, including a support vector machine (SVM), an adaptive neural network based on the fuzzy inference system (ANFIS), and a novel hybrid model that combines earthworm optimisation (EO) and ANFIS (EO-ANFIS). The study also leverages the empirical model offered by the United States Bureau of Mines. The outcomes highlighted that the predictions of the three individual components prove to be more accurate compared to the vectoral sum of PPVs of particle velocity. However, the latter remains a valuable metric for evaluating the magnitude of BIGV in open-pit mines. Notably, the hybrid EO-ANFIS model emerges as the most accurate, achieving an impressive ~ 75% accuracy across 10 quarries characterised by distinct geological conditions. [ABSTRACT FROM AUTHOR]

In order to analyze the variation characteristics and formation mechanism of environmental vibration caused by metro operation, field measurement of ground vibration and tunnel wall vibration are carried out along a metro line in Beijing. Vibration sample data of all trains in a whole day are analyzed statistically. And the main reasons for the discreteness of environmental vibration are summarized by comparing the vibration variety rules of different trains and different sections. The result shows as following. Firstly, the difference of vibration level at ground point can reach at most 14.6 dB, with a large degree of dispersion. Although the average value of twenty trains could meet the requirement of the standard prescribed limit, but there is still 30% ~ 50% of vibration values exceeding the standard prescribed limit. Secondly, the difference of vibration level at tunnel points reaches at most 22.1 dB, which is caused by the abnormal status of five vehicles in all trains on the day with the symptom of wheel irregularity. And the average value of maximum Z weighted vibration acceleration level (VLZmax) at tunnel wall points caused by them is 90.6 dB. Thirdly, vibration level at tunnel wall points between different sections induced by thesame vehicle is changed notably. And there is an important correlation with vehicle status. When the wheel is out of roundness visibly, the vibration level difference between different sections is changed more significantly. The maximum noise level can reach 10.7 dB, which is twice of 'normal vehicle', indicating that the deterioration of wheel state and track state will further change the wheel-rail interaction and aggravate the environmental vibration level. In addition, after wheel reprofiled of abnormal vehicles, the vibration level at ground point close to building is effectively reduced and all vibration values are reduced to less than 70 dB. [ABSTRACT FROM AUTHOR]

The mitigation of train-induced ground vibrations by track solutions is investigated by calculations and measurements. The calculation by a wavenumber domain method includes the correct vehicle–track interaction and the correct track–soil interaction. Some theoretical results for elastic elements and an increased bending stiffness of the track are presented where the force transfer of the track and the vehicle–track interaction are calculated for the high-frequency dynamic mitigation, and the force distribution along the track is calculated for the low-frequency mitigation which is due to the smoother impulses from the passing static loads. Measurement results for the ground vibration near isolated and un-isolated tracks are given for several under-sleeper pads, for under-ballast mats, and for several under-ballast plates and ballast troughs. The elastic elements yield a resonance frequency of the vehicle–track–soil system and a high-frequency reduction of the dynamic axle loads which depends mainly on the softness of the pads or mats and which can be improved by a higher sleeper mass. In addition, all troughs and most of the soft elements show a low-frequency reduction which is attributed to the scattered impulses of the static axle loads. Besides this main contribution of the article, the problem of a soft reference section on a different soil is discussed and recommendations for better ground vibration measurements of mitigation effects are given. [ABSTRACT FROM AUTHOR]

Trainload is characterized by a number of factors such as axle load magnitude, number of carriages, train speed, etc. These factors likely contribute to the ground vibration induced by a high-speed train. While vibration effects associated with train speed have received much research attention in the literature, limited attention has been paid to the effects associated with the number of train carriages. In this study, we investigate how the number of train carriages affects ground vibrations caused by a high-speed train. A finite element model is used to simulate the vibration of a layered ground caused by a Shinkansen train moving at a speed of 70 m/s (252 km/h). There are 8 cases of trainload considered, and each case corresponds to a number of train carriages. The simulation result shows that the number of train carriages has a significant influence on the amplitude of ground vibration. The influence is more pronounced for locations near the excitation source. When the train has 4 or fewer carriages, the vibration amplitude increases with increasing the number of train carriages. However, when the train has 4 or more carriages, the vibration amplitude remains unchanged. It is therefore recommended that in a simulation of train-induced ground vibration, we should only use a sufficient number of train carriages (about 4 to 5 carriages). If more train carriages are used, we still get the same result, but the computational cost increases significantly. [ABSTRACT FROM AUTHOR]

Underground train–induced vibrations can cause nearby residents discomfort, damage to buildings, and disturbance for equipment. One of the most effective ways to reduce vibrations is using wave barriers along the propagation path of the waves. Many parameters are involved in determining the efficiency of these barriers: the barrier's dimension, distance from the source of vibration, and material property, to name a few. Simultaneous study of these parameters is complex since numerical analysis of alternatives is time-consuming. Therefore, in this study, by coupling the three-dimensional finite element method and an optimization algorithm, an attempt is made to provide a comprehensive solution to find the optimal wave barriers for Tehran metro line 4 as a case study. The current study evaluates two strategies: using in-filled trenches and topology-optimized barriers. In the first strategy, results show that soft-material trenches with maximum depth close to the observation point have the best performance. Further investigations on jet grout trenches show better performance in stiffer soil and lower train speed. Using dual trenches improves performance only up to 2%, so it does not provide a suitable option. For various practical reasons, there may be no tendency to use soft-material trenches, which perform well in vibration reduction. Therefore, in the second strategy, the improvement of a hard trench (jet grout) performance by topology optimization is investigated. According to this study, topology optimization is an effective method for improving barrier performance. [ABSTRACT FROM AUTHOR]

The technological difficulties related with blasting operations have become increasingly significant. It is crucial to give due consideration to the evaluation of rock fragmentation and the threats posed by environmental effect of blasting (EEB). To address these challenges, numerous scholars have conducted extensive research employing various assessment techniques with the aim of mitigating risks and preventing the emergence of unfavorable EEB. The occurrence of EEB is prevalent during the excavation of hard rock, and it presents significant hazards to personnel safety, equipment integrity, and operational continuity. Therefore, conducting a systematic review of EEB is of utmost importance as it enables a comprehensive understanding of the contributing factors. Such an understanding plays a vital role in advancing EEB prediction and prevention methods. The careful selection of an appropriate EEB assessment method is a crucial aspect of blasting operations. However, there is a lack of comprehensive discussions on the applications of machine learning (ML) and optimization algorithms (OA) in addressing various EEB. Only a limited number of papers have briefly touched upon this topic. Therefore, the primary objective of this paper is to bridge this gap by conducting an analysis of global trends using CiteSpace and VOSviewer software from the year 2000 onwards. It comprehensively explores EEB classification and definition, encompassing air overpressure (AOp), ground vibration, dust, backbreak, flyrock, and rock fragmentation. Furthermore, the paper provides a compendium of the most recent ML and OA prediction techniques used to addresses EEB. Finally, the paper concludes by proposing future directions for exploring innovative approaches that combine data-driven ML techniques with knowledge-based or physics-based methods. Such integration has the potential to mitigate hazards during blasting operations and reduce the likelihood of unfavorable EEB occurrences. [ABSTRACT FROM AUTHOR]

With the development of urban rail transportation, the environmental vibration problem caused by the running of metro vehicles has received attention. In order to reduce ground vibration near buildings caused by metro vehicles running on viaducts, this paper establishes the train–track–viaduct rigid–flexible coupling dynamics model and pier–soil–building finite element model and carries out the simulation calculation and analysis of ground vibration. The influence of train speed and fastener stiffness on ground vibration is explored, and the vibration reduction effect of the track vibration reduction pad and continuous support vibration reduction structure is studied. The results show that the ground vibration near the building caused by the train running on the viaduct decreases with the reduction in speed, when the speed is reduced to 40 km/h, the vibration attenuation is slower as the speed continues to be reduced; the reduction in the vertical stiffness of fasteners can reduce ground vibration; the arrangement of the vibration damping pad can effectively reduce ground vibration, and after installing a vibration damping pad, 0–23 Hz and 50–80 Hz ground vibration speeds are effectively suppressed. In order to meet the environmental requirements for ground vibration, the vehicle speed can be reduced to less than 35 km/h or vibration damping mats can be installed.

This article explores the application of the air deck method in blasting activities at PT Semen Baturaja (Persero), Tbk. The study aims to minimize ground vibration and optimize limestone fragment size to improve the crushing plant's effectiveness and reduce the impact on nearby residential areas. The research involved comparing blasting activities with and without the air deck method, analyzing ground vibration values and limestone fragmentation. The results indicate that the air deck method successfully reduces ground vibration and improves limestone fragmentation. The study suggests that the air deck method is an efficient and effective approach to optimize blasting activities while considering natural and geographical factors. [Extracted from the article]

Sheet piles are extensively used as foundation structures in urban environments. However, the vibrations associated with sheet pile construction can potentially adversely affect existing buildings, as well as cause discomfort to nearby residents. This study aims to analyze ground vibration response during the driving and extraction of sheet piles. To this end, field tests of U-shaped sheet piles were conducted in Beijing silty clay, during which ground vibrations in the near-field were monitored. Subsequently, a numerical model was developed using the coupled Eulerian–Lagrangian method to simulate the pile–soil interaction characteristics and to investigate ground vibration intensity in the far-field. The research results indicate that the ground vibration response modes during the driving and extraction of sheet piles are distinctly different. Due to the entry effect, the critical depth during pile driving typically occurs in shallow soil layers, while during pile extraction, the critical depth generally corresponds to the pile's embedded depth to overcome the soil locking effect. Ground vibrations rapidly decrease in the near-field (<6 m), while in the far-field (>6 m), the attenuation rate significantly slows down. Vibrations can be widely perceived by residents at radial distances of less than 12 m. Through a systematic assessment, it was concluded that sheet pile construction is unlikely to directly damage surrounding buildings but may inconvenience nearby residents. Additionally, a parametric analysis of the vibration source revealed that appropriately adjusting the driving frequency and amplitude can effectively reduce vibration levels. [ABSTRACT FROM AUTHOR]

With the continuous expansion of the scale of power grid and transportation infrastructure construction, the number of crossovers between transmission lines and high-speed railways continues to increase. At present, there is a lack of systematic research on the dynamic characteristics of transmission tower-line structures crossing high-speed railways under vehicle-induced ground vibration. This article focuses on the phenomenon of accidents such as line drops when crossing areas in recent years and establishes a high-speed train track foundation soil finite element model in ABAQUS that considers track irregularity. The three-dimensional vibration characteristics and attenuation law of train ground vibration are analyzed. Acceleration data for key points are also extracted. A separate finite element model of the transmission tower-line system is established in ANSYS, where acceleration is applied as an excitation to the transmission tower-line system, and the coupling effect between the tower and the line is considered to analyze its dynamic response. Subsequently, modal analysis is conducted on the tower-line system, providing the vibration modes and natural frequencies of the transmission tower-line structure. The effects of factors such as train speed, soil quality, and distance from the tower to the track on the dynamic response of the transmission tower-line system under vehicle-induced ground vibration are studied. The results show that the speed range (300 km/h–400 km/h) and track distance range (4.5 m–30 m) with the greatest impacts are obtained. The research results can provide a reference for the reasonable design of transmission tower-line systems in high-speed railway sections. [ABSTRACT FROM AUTHOR]

Mechanical action can damage physical objects, such as building structures. The transfer of energy to the ground through the falling mass, forming a crater, can cause kinematic forces in the soil medium. An effect of these forces, connected with the technology of geotechnical machines, is vibrations of the ground and building structures. When finding the energy impact on the object is difficult or even impossible, vibration monitoring and indirect estimation of the negative energy impact effects is possible. Commercial off-the-shelf solutions exist for vibration monitoring and recording, but they are dedicated to one application type and are relatively expensive. This paper presents a proprietary system for monitoring and recording vibrations of building objects transmitted through the ground. This allows for local registration and remote administration and presentation of data via a computer network. Vibrations can be analysed according to the requirements of developers and clients. The developed system shows that creating an effective approach for collecting data on building vibrations using components from different suppliers is possible. The waveforms collected using the system confirm the effectiveness and flexibility of the presented solution, providing a possibility of using the results to decide whether the vibrations are within the standard limits. [ABSTRACT FROM AUTHOR]

The vehicle–track interaction generates forces and consequently vibrations in the environment. The interaction has been analysed by the simultaneous measurements of vehicle, track and ground vibrations during test runs with varied train speeds. The special effects of the passage over a bridge and through a tunnel are studied and compared with the measurements on a conventional ballasted surface line. The maximum amplitudes, narrow band and one-third octave band spectra are presented for the axle-box accelerations and for the track, bridge and ground vibrations. The different frequencies and frequency bands are related to wheel out-of-roundness, track alignment errors, the sleeper passage and the wheelset–track resonance. An axle impulse component has been observed at the track, at the near-field soil and as a scattered version in the far field. Specific results can be found for the bridge track, where clearly speed-dependent bridge resonances occur due to the axle sequence of the train, and for the tunnel track where soft rail pads are responsible for a strong amplification around the wheelset–track resonance. On the other hand, the axle impulses are strongly reduced by the tunnel track, and the scattered axle impulse component is not as relevant as for the surface track. As a consequence, a strong mid-frequency amplitude reduction of the tunnel compared to the surface line has been measured for low and high train speeds by the Federal Institute of Material Research and Testing (BAM) and by other institutes. [ABSTRACT FROM AUTHOR]

Mining and construction sites experience ecological consequences, such as ground vibrations and fly rock, owing to blasting activities. Apart from the traditional techniques, it is critical to determine the design parameters of a blast which influence the ground vibrations, created by the blasting activities, and to mitigate the effects of ground vibrations as an end result. A unique validation tool developed on statistically designed response surface methodology (RSM) has been suggested for determining the rate of influence of blast design parameters on the ground vibrations with a case study of a limestone mine. Design-Expert software has been used to assess the intended statistically designed model. The novelty of this research study is to design the ANOVA model constructed by the Response Surface Methodology (RSM) using the 'Design-Expert 11.0' and it was validated using the field values. Consequently, the Response Surface 3D Model Graph has been constructed to determine the significant influencing parameters associated with ground vibrations (PPV). Further, about 45 numbers of blasting events were investigated and the effects of four blast design factors on the ground vibrations, namely, decking length, inter-hole delay, inter-row delay and stemming length, were monitored accordingly. Besides, the measurements of peck particle velocity (PPV) as a vibration identifier and their effect on the growth of backbreak were measured in each blasting event. The following two significant parameters, such as (i) the root mean square error (RMSE) and (ii) coefficient of multiple correlation (R2), were studied to find out the efficacy of the suggested models. Linking the values predicted by the models, it had been established that the decking length and delay between the holes (inter-hole delay, ms) are significantly contributing to ground vibrations when compared to the delay between rows (inter-row delay and stemming length respectively) which are found to be moderate contributors of ground vibrations. [ABSTRACT FROM AUTHOR]

In order to analyze the ground vibration responses induced by the dynamic loads in a tunnel, this paper proposes a new simplified tunnel–soil model. Specifically, based on the basic theory of the thin-layer method (TLM), the basic solution of three-dimensional layered foundation soil displacement was derived in the cylindrical coordinate system. The perfectly matched layer (PML) boundary condition was applied to the TLM. Subsequently, a tunnel–soil dynamic interaction analysis model was established using the volume method (VM) in conjunction with the TLM-PML method. The displacement frequency response function of the foundation soil around the tunnel foundation was derived. Finally, a ground vibration test under an impact load in a tunnel was carried out. The test and calculated results were compared. The comparison results show that the ground vibration acceleration response values within 25 m from the load are similar. Compared with the test results, the theoretical calculation results exhibit a decreasing trend in the range of 40–80 Hz between 25 and 60 m, with the maximum reduction being approximately one order of magnitude. In addition, the experimental comparison demonstrates that the model can be used to analyze the ground vibrations caused by underground loads.

The ground vibration caused by the operation of high-speed trains has become a key challenge in the development of high-speed railways. In order to study the train-induced ground vibration affected by geotechnical heterogeneity, an efficient frequency–wave-number method coupled with the random variable theory model is proposed to quickly obtain the numerical results without losing accuracy. The track is regarded as a composite Euler–Bernoulli beam resting on the layered ground, and the spatial heterogeneity of the ground soil is considered. The ground dynamic characteristics of an elastic, layered, non-uniform foundation are investigated, and numerical results at three typical train speeds are reported based on the developed Fortran computer programs. The results show that as the soil homogeneity coefficient increases, the peak acceleration continuously decreases in the transonic case, while it gradually increases in the supersonic case, and the ground acceleration spectrum at a far distance obviously decreases; the maximum acceleration occurs at the track edge, and a local rebound in vibration attenuation occurs in the supersonic case.

High-speed train operation may cause vibration near track facilities and propagate far through the ground, affecting people’s lives, work, and normal use of precision instruments in an urban environment. An efficient numerical method is proposed to calculate the non-uniform ground vibration under a moving high-speed railway load. The theory of stochastic variables is used to describe the soil spatial variability of the non-uniform layered elastic ground, and the coupled 2.5D random finite element method (FEM) is proposed to reduce the computational cost without losing accuracy. Vibration propagation and attenuation of the non-uniform layered ground are investigated and the effect of train speed and soil non-homogeneity are analyzed. Results show that (1) at cross speed and high speed, the homogeneity coefficient of the layered ground has the most important influence on the ground vibration amplitude; (2) the upward acceleration is much larger than the downward acceleration at most speeds, and at cross speed and high speed, the acceleration amplitude decreases with the increase in the homogeneity coefficient; (3) as train speed increases from 60 m/s to 130 m/s, the influencing range of the homogeneity coefficient increases to 10 m from 2 m; and (4) the phenomenon of an in increase in local rebound can be observed in the velocity and acceleration attenuation curve at cross speed when the ground soil has a weaker homogeneity.

Interlaid rock is an important component in the construction of neighborhood tunnels that supports and reinforces the area between two tunnels. However, the blasting load during excavation can sometimes damage the interlaid rock and threaten the stability of a tunnel’s structure. This paper presents a case study of the small clearance section of the Liantang highway tunnel project in Shenzhen, China, where the minimum distance between the two tunnels involved is only 0.5 m. To reduce the damage to the interlaid rock caused by blasting loads, we proposed a four-part excavation method with a vibration-cushioning rock layer in the following tunnel of neighborhood tunnels. Numerical simulation was used to model the damage prevention mechanism of the vibration-cushioning rock layer and to better understand the propagation of cracks in the interlaid rock. Furthermore, based on the simulation results, combined microseismic controlled-blasting technology was implemented, using innovative blasting patterns combined with different charge structures and blasting equipment designed according to the varying thickness of the interlaid rock. Finally, this implementation succeeded in protecting interlaid rock during blasting operations.

To predict the environmental vibration caused by high-speed railways, a prediction method combining actual measurement and simulation is proposed based on the vibration prediction formula proposed by Federal Transportation Administration (FTA). On a subgrade section of the Nanchang-Jiujiang Intercity Railway in China, the ground vibration acceleration level and the line source transfer mobility of the soil layer were measured using the field vibration test and the hammer test. Second, the force density function of the moving train is determined by applying the prediction formula inversely. In conjunction with the line source transfer mobility calculated by the finite element simulation, the ground vibration caused by the high-speed train operating in the subgrade section is finally predicted. The results indicate: This method’s prediction result is nearly identical to the variation law of the measured vibration acceleration level curve, and the vibration acceleration level of each center frequency in the frequency range above 5 Hz is essentially identical; the error between the result of the weighted vibration acceleration level and the measured value is only 1.1% at 10 m (71.84 dB and 72.64 dB, respectively). The predicted and measured results of the Z vibration level at 30 m are 66.02 dB and 68.94 dB, with an error of 4.23%. It can be seen that the prediction accuracy of this method is reasonably good. [ABSTRACT FROM AUTHOR]

Blasting activities carried out in mining activities always produce effects that will have an impact on the surrounding area of the blasting site, from some of the blasting effects that exist one of which is soil vibration, so that at the research site in Pit Jongkang which is close to the village with a distance of approximately 300-400m it is very important to measure the level of vibration leading to the village so that the results of the vibration caused by the blasting process are obtained. The stages undertaken in this study that begins with the study of literature on several sources that discuss the themes to be taken in the study followed by field observation with the aim to determine which locations are suitable as research materials and subsequent data retrieval required in data processing later. Actual PPV value Data obtained from the measurement of soil vibration is 1 mm/s, 1.5 mm/S, 1.66 mm/S, 0.71 mm/s, 1.44 mm/s, 0.91 mm/s, 1.7 mm/s, 0.46 mm/s, 1.1 mm/s, 0.7 mm/s, 0.54 mm/s, 1.7 mm/s, 0.48 mm/s, 0.6 mm/s, 1.3 1.56 MM/s. Based on the results of the analysis it was found that at the research site did not show any vibration of the soil that exceeds the company's determination of 2 mm/s, therefore for the amount of explosive charge recommended that the maximum amount of explosive charge so that the vibration caused does not exceed the PPV standard. so for the maximum amount of explosive filling in accordance with the PPV standard is at a distance of 300 m, 400 m, and 500 m by 31 kg, 55 kg, and 86 kg of the hole. With the use of the recommended surface delay is the pair of surface delay 42 ms and 67 ms in the echelon cut circuit pattern, because it slightly efficiencies the time and the resulting PPV does not exceed 2 mm/s. [ABSTRACT FROM AUTHOR]

With the aim of predicting the environmental vibrations induced by an elevated high-speed railway, a machine learning method was developed by combining a random forest algorithm and Bayesian optimization, using a dataset from on-site experiments. When it comes to achieving a rapid and effective prediction of environmental vibrations, there is little research on comparisons between and verifications of different algorithms, and none on the parameter tuning and optimization of machine learning algorithms. In this paper, a field experiment is firstly carried out to measure the ground vibrations caused by high-speed trains running on a bridge, and then the environmental vibration characteristics are analyzed in view of ground accelerations and weighted vibration levels. Subsequently, three machine learning algorithms using linear regression, support vector machine, and random forest are developed using an experimental database, and their prediction performance is discussed. Finally, two optimization models for the hyperparameter set of the random forest algorithm are further compared. The results show that the integrated random forest algorithm has a higher accuracy in predicting environmental vibrations than linear regression and the support vector machine; the Bayesian optimization has an excellent performance and a high efficiency in achieving efficient and in-depth optimization of parameters and can be combined with the RF machine learning algorithm to effectively predict the environmental vibrations induced by the high-speed railway. [ABSTRACT FROM AUTHOR]

This paper presents a novel rock engineering system (RES) based method for estimating blast-induced vibration attenuation risk index and predicting peak particle velocity (PPV). The RES approach involves three key steps, which are the identification of influencing parameters, the construction of an interaction matrix and the rating of parameters based on their influence on ground vibration. The selected parameters are the scale distance (SD), the ratio of the scale distance to stemming divided by the burden (SD/TB), the distance of the monitoring station (D), the scale distance divided by the burden (SD/B), the ratio of the scale distance to powder factor (SD/PF) and the ratio of scale distance to spacing divided by the burden (SD/SB). The results indicated that all the six parameters considered have statistically significant influences on the constructed interaction matrix system, with the SD having the highest weighty factor (21.43%) while SD/TB is the lowest (14.29%). The maximum rating of the parameters is 5, 5, 4, 5, 5, 4 for SD, D, SD/B, SD/PF, SD/SB and SD/TB, respectively. The attenuation risk index ranges from 14.29 to 63.43, and the slope of the actual measured PPV against the calculated attenuation risk index is negative. The developed RES-based model demonstrated better performance and a reliable method for ground vibrations prediction with a higher degree of accuracy, considering its higher determination coefficient (R2 = 0.96) and smaller error (RMSE = 1.08, MAD = 0.79, MAPE = 9.95) compared to multiple regression, Langefors & Kihlstrom and Hudaverdi models.

Ground vibrations near railway lines are generated by the forces that are acting between wheel and rail. It seems to be a straight forward assumption that the vehicle dynamics are important for the level and the frequencies of the excitation forces. Different vehicle dynamics phenomena are analysed for their role in the excitation of ground vibrations: rigid body modes of the bogies, elastic (bending) modes of the car body, and elastic modes of the wheelset. The theoretical analyses use rigid body models, simplified elastic models, and detailed elastic models. Some of these problems are vehicle–track interaction problems where 3D finite-element boundary-element models have been used for the track and soil. It is shown that the rigid or flexible vehicle modes are well in the frequency range of ground vibrations (4 to 100 Hz). They have an influence on the excitation force but the additional forces are rather small and can be neglected in ground vibration prediction. The theoretical results are checked by experimental results of a simultaneous measurement of vehicle, track, and ground vibrations.

The dynamic load of high-speed railway train can cause environmental vibration problems. In order to study the environmental vibration effect caused on the viaduct bridge section and embankment section by high-speed train, the field test of the Zhengzhou - Xi’an high-speed railway is carried out, and the ground vibration characteristics and attenuation law of viaduct bridge section and embankment section are compared and analyzed. The test results show that the vibration response of the embankment section is greater than that of the viaduct bridge section, and the attenuation effect in the near-field area of the viaduct bridge section is higher than that in the near-field area of the embankment section. There are multiple rebound increases in the process of vibration propagation, and the ground vibration rebound of the embankment section lags behind that of the viaduct bridge section. The increase rate of secondary rebound in the viaduct bridge section and embankment section is significantly greater than that of primary rebound. The attenuation of Z vibration level with the distance conforms to the law of logarithmic attenuation. The Z vibration level attenuation formula in the loess area is obtained by fitting, and the maximum deviation appears in the rebound increasing area. The infinite element-viscoelastic coupling boundary is introduced to establish a 3D track-soil-vibration isolation trench numerical model of the embankment section. The influence of vibration isolation trench on vibration reduction and isolation of high-speed railway is analyzed. The results show that the vibration isolation effect of empty trench on the medium and high frequency (30 - 60 Hz) vibration wave is more obvious than that of low frequency (1 - 20 Hz), and it has the function of low-pass filtering. The vibration isolation effect of empty trench is better than that of filled trench, but soft materials can be filled in the trench considering the stability of trench walls. The research results can provide references for the design of high-speed railway and the evaluation and control of environmental vibration.

The mitigation of train-induced ground vibrations by track solutions is investigated by calculations and measurements. The calculation by a wavenumber domain method includes the correct vehicle–track interaction and the correct track–soil interaction. Some theoretical results for elastic elements and an increased bending stiffness of the track are presented where the force transfer of the track and the vehicle–track interaction are calculated for the high-frequency dynamic mitigation, and the force distribution along the track is calculated for the low-frequency mitigation which is due to the smoother impulses from the passing static loads. Measurement results for the ground vibration near isolated and un-isolated tracks are given for several under-sleeper pads, for under-ballast mats, and for several under-ballast plates and ballast troughs. The elastic elements yield a resonance frequency of the vehicle–track–soil system and a high-frequency reduction of the dynamic axle loads which depends mainly on the softness of the pads or mats and which can be improved by a higher sleeper mass. In addition, all troughs and most of the soft elements show a low-frequency reduction which is attributed to the scattered impulses of the static axle loads. Besides this main contribution of the article, the problem of a soft reference section on a different soil is discussed and recommendations for better ground vibration measurements of mitigation effects are given.

Prediction and parameter optimization are effective methods for mine personnel to control blast-induced ground vibration. However, the challenge of effective prediction and optimization lies in the multi-factor and multi-effect nature of open-pit blasting. This study proposes a hybrid intelligent model to predict ground vibrations using a least-squares support vector machine (LSSVM) optimized by a particle swarm algorithm (PSO). Meanwhile, multi-objective particle swarm optimization (MOPSO) was used to optimize the blast design parameters by considering the vibration of particular areas and the bulk rate of blast fragmentation. To compare the prediction performance of PSO-LSSVM, a genetic-algorithm-optimized BP neural network (GA-BP), unoptimized LSSVM, and BP were used, by applying the same database. In addition, the root-mean-squared error (RMSE), the mean absolute error (MAE), and the correlation coefficient (r) were regarded as the evaluation indicators. Furthermore, the optimization results of the blasting parameters were obtained by quoting the established vibration prediction model and bulk rate proxy model in MOPSO and verified by field tests. The results indicated that the PSO-LSSVM model provided the highest efficiency in predicting vibrations with an RMSE of 1.954, MAE of 1.717, and r of 0.965. Furthermore, the blasting vibration can be controlled by using the two-objective optimization model to obtain the best blasting parameters. Consequently, this study can provide more specific recommendations for vibration hazard control. [ABSTRACT FROM AUTHOR]

The soil conditions substantially influence the intensity of underground metro train-induced ground vibration. However, assessing the influence of metro train-induced vibration on nearby structures is difficult due to problems in acquiring soil characteristics' field data. An optimized artificial neural network (ANN)-based hybrid prediction model is proposed to predict the underground metro train-induced ground vibration to address this issue. Particle swarm optimization (PSO) and genetic algorithm (GA) are used in the hybrid model to optimize the neural network's weights and biases. The datasets obtained by the validated numerical model are used to train the neural network. An explicit time domain, two-dimensional (2D) numerical model is developed using the finite element method (FEM) based on a two-step methodology and validated with experimental results of Delhi metro sites. Good agreement is observed between the numerical and experimental results in both time and frequency domains. The proposed hybrid PSO-ANN and GA-ANN model considered several soil properties such as density, Poisson's ratio, damping, Young's modulus and wave speed while predicting train-induced ground vibration. The PSO-ANN model predicted the outcome with an average error of 0.86%. Moreover, the proposed PSO-ANN model is also compared with the Federal Transit Administration's (FTA) semi-empirical approach of vibration assessment, linear support vector machine (SVM) and classification and regression tree (CART). The hybrid PSO-ANN model predicted the outcomes with greater accuracy than the basic ANN model, linear SVM, CART, GA-ANN and FTA's approach. Additionally, the hybrid model can consider the effect of parameters such as vehicle characteristics, suspension system, speed and tunnel depth. [ABSTRACT FROM AUTHOR]