Ground-borne Noise Research Articles

Book Review: Review of ‘Train-Induced Groundborne Vibration and Noise in Buildings’

Book Review: Review of ‘Train-Induced Groundborne Vibration and Noise in Buildings’

Groundborne noise and vibration control at the Toronto Four Seasons Centre for the Performing Arts

The Four Seasons Centre for the Performing Arts, Canada’s first purpose-built opera house had its grand opening on June 14, 2006. Occupying an entire block of the financial and theatre district in downtown Toronto (across from the Sheraton Hotel), the facility with its 2,000 seat auditorium, is the new home of the Canadian Opera Company and the performance venue for the National Ballet of Canada. A major challenge for the project’s downtown location was isolating the auditorium from the vibration and noise from the adjacent subway system on University Avenue and surface streetcars on Queen Street. A ‘‘building within a building’’ vibration isolation design was developed that set the entire auditorium, stage, and rehearsal hall on rubber isolation bearings. This paper provides design details and the procedures used to ensure that the groundborne noise from outside activities would be inaudible. Results of follow-up measurements are presented which confirmed that the vibration design effectively mitigated the outside vibration and noise intrusion inside the auditorium to achieve background noise levels from exterior sources equivalent to the threshold of human hearing.

Numerical modelling of ground-borne noise and vibration in buildings due to surface rail traffic

This paper deals with the numerical computation of the structural and acoustic response of a building to an incoming wave field generated by high-speed surface railway traffic. The source model consists of a moving vehicle on a longitudinally invariant track, coupled to a layered ground modelled with a boundary element formulation. The receiver model is based on a substructuring formulation and consists of a boundary element model of the soil and a finite element model of the structure. The acoustic response of the building's rooms is computed by means of a spectral finite element formulation. The paper investigates the structural and acoustic response of a multi-story portal frame office building up to a frequency of 150 Hz to the passage of a Thalys high-speed train at constant velocity. The isolation performance of three different vibration countermeasures: a floating-floor, a room-in-room, and base-isolation, are examined.

An evaluation of the accuracy of the Federal Transit Administration approved, groundborne noise and vibration prediction model for rail transit systems; a case study for a new subway line using post construction, transit operation measurements

The groundborne noise and vibration model developed by Nelson and Saurenman in 1984, now recognized by the Federal Transit Administration as the approved model for new transit system facilities, is entering its third decade of use by engineers and consultants in the transit industry. The accuracy of the model has been explored in the past (e.g., Carman and Wolfe). New data obtained for a recently completed extension to a major heavy rail transit system provides an opportunity to evaluate the accuracy of the model once more. During the engineering design phase of the project, noise and vibration predictions were performed for numerous buildings adjacent to the new subway line. The values predicted by the model were used to determine the need for and type of noise and/or vibration control measures. After the start of transit operations on the new line, noise and vibration measurements were made inside several of the buildings to determine whether the criteria were in fact achieved. The measurement results are compared with the values predicted by the model. The predicted and measured, overall noise and vibration levels show very good agreement, whereas the spectral comparisons indicate some differences. Possible reasons for these differences are offered.

Vibration response of buildings to rail transit groundborne vibration

The FTA guidelines for detailed analysis and prediction of groundborne noise and vibration generated by rail transit systems are based on established empirical methods. The procedures for the measurement of vehicle/track system source strength and the attenuation of vibration as it propagates with distance through the ground are generally accepted practice at this time. However, characterization of the building response is open to debate, due in part to the wide array of building construction encountered adjacent to transit systems. Numerous measurements that have been obtained in a variety of building construction types are presented and preliminary conclusions are drawn regarding the responses of several common building types to rail transit groundborne vibration.

Reduction of ground vibration by means of barriers or soil improvement along a railway track

Trains running in built-up areas are a source to ground-borne noise. A careful design of the track may be one way of minimizing the vibrations in the surroundings. For example, open or infilled trenches may be constructed along the track, or the soil underneath the track may be improved. In this work, the influence of the track design and properties on the level of ground vibration due to a vehicle moving with subsonic speed is examined. A coupled finite element-boundary element model of the track and subsoil is employed, adopting a formulation in the moving frame of reference following the vehicle. The computations are carried out in the frequency domain for various combinations of the vehicle speed and the excitation frequency. The analyses indicate that open trenches are more efficient than infilled trenches or soil stiffening–even at low frequencies. However, the direction of the load is of paramount importance. For example, the response outside a shallow open trench may change dramatically when horizontal load is applied instead of vertical load.

Isolation of Buildings from Ground-Borne Noise Using a Sand Stratum

The effect of an elastic stratum in reducing ground-borne sound transmission in buildings to be built above railway tunnels is investigated, by considering a sand layer between the bedrock and load bearing elements of the building. It is assumed that the initial vibrational energy that propagates from the foundation is in the form of quasi-longitudinal waves. The complete model as presented by the author in a previous paper is considered. Calculated results are compared with previous results for a typical building and it is shown that a sand layer can considerably reduce upward sound transmission in the building. The results of a parametric study to investigate the influence of the type of load-bearing elements and the thickness of the layer, on transmission of structure-borne sound in the building, are presented.

지하철에 의한 지반진동 예측에 관한 연구

Ground-borne noise and vibration generated by underground transit system has been recognized as an important environmental problem. This study reviews several of the procedures that have been used to predict ground-borne vibration. The vibration responses are measured at three sites that have different soil qualities. The measured vibration levels are compared with the predicted results by previously used vibration level prediction models. There are some drawbacks to apply these prediction models to selected sites because most of the existing prediction models are primarily based on empirical data and all of them lack of analytical models for the mechanism of ground-borne vibration generation. radiation, and propagation. In this study a numerical method, which is based on explicit differential method, is used to compensate for the shortcomings of existing prediction models. Although numerically computed results are not quantitatively in good agreement with the measured results, the trends are comparable in the sense that vibration level does not decrease monotonically with distance. Also, the site with the deepest tunnel gives the highest vibration level.

Impact of sound and vibration of the North–South high-speed railway connection through the city of Antwerp Belgium

In the European High-Speed Train Network the infrastructure of the North–South connection in Antwerp needs significant modifications. For the section between Berchem and Antwerp Central Station the existing track on the high level embankment will be incorporated into concrete structures providing a three level track access to the station. For the section between Antwerp Central Station and Dam two drilled tunnels are planned providing the station with pass-through facilities instead of being an “end” station as at present. The paper focuses on the methods of practical research and the resulting measures regarding the impact of sound and vibration on the environment. An essential part of this study is the impact of the planned construction of a double railway tunnel underneath the city of Antwerp. At certain locations, the distance between the foundations of the houses and the top of the tunnel is only 4 m. The study considers the projected vibration levels on the rail, the tunnel invert, building foundations and upper floors of the buildings. Also the ground-borne noise is evaluated. The study identifies the measures necessary at the rail mounting level. As a result, a floating slab has been proposed and the effects on the environment are estimated.

Boundary element analysis of the steady-state response of an elastic half-space to a moving force on its surface

The paper deals with the boundary element method formulation of the steady-state wave propagation through elastic media due to a source moving with constant velocity. The Green's function for the three-dimensional full-space is formulated in a local frame of reference following the source. This is appropriate for the analysis of, for example, ground borne noise from railway or road traffic. The frequency-domain fundamental solution is derived from the corresponding time-domain solution by means of Fourier transformation. To obtain a closed form solution, a part of the time-domain kernel functions is approximated, but the error which is introduced in this way is insignificant. Numerical examples are given for a moving rectangular load on an elastic half-space. The results from a boundary element code based on the derived Green's function are compared with a semi-analytic solution.

REDUCING GROUNDBORNE VIBRATIONS: STATE-OF-THE-ART STUDY

The project RENVIB has been sponsored by the Union of International Railways to further the knowledge on train-induced ground vibration. The long-term aim is to develop a general model that will predict the vibration caused by trains operating in tunnels and on the surface. A State-of-the-Art survey was carried out during Phase 1 of the project and that is summarized in this paper. This highlighted the lack of standards in the assessment of groundborne noise and inconsistencies in the treatment of low-frequency vibration in other standards. Phase 2 is current and is concentrating on some preliminary validation of existing models using measurement data from national vibration mitigation projects.

Controlling subway noise in the LG Arts Center—Sangnam Hall

The LG Arts Center in Seoul, Korea is a multifunction facility including a Hall intended for a variety of performances including western drama and dance, chamber music, traditional Korean folklore plays, opera, oration, and digital recordings. The 1050 seat Hall is designed to guard against both airborne and groundborne noise. Airborne noise is controlled by enclosing the stage house and the audience chamber with 200-mm airspace double walls. Horizontal and vertical acoustical joints at the Hall structure interface with the main building and control groundborne noise generated by the subway trains in a tunnel adjacent to the site. The subway tunnel and the foundation structure of the building are in the same rock strata and the groundborne noise is transmitted as structure-borne noise to the Hall through the lower-level parking structures. Without isolation the noise from the subway would have intrusive effects on the multifunctional use of the performance hall and stage area. Vibration isolation rubber bearings are provided in the interface design to reduce the noise to acceptable levels in the noise critical space. The impact of the proposed isolation bearing pads on the building design and their acoustical benefits are discussed.

THE CALCULATION AND ASSESSMENT OF GROUND-BORNE NOISE AND PERCEPTIBLE VIBRATION FROM TRAINS IN TUNNELS

The assessment and calculation of perceptible vibration and ground-borne noise from the operation of railway tunnels are discussed. The data and methodologies reported include material obtained by the authors in studies of the operation and construction of the proposed 108 km long high speed railway link between London and the Channel Tunnel which include an 18 km long tunnel beneath residential areas in London.

Ground-borne noise and vibration damping

A ground-borne noise and vibration damping system in which is a track bed formed with rails for a railway vehicle and generating noise and vibration, a structure is to be protected against the noise and vibration; and a damper for ground-borne noise and vibration is embedded vertically in the ground and interposed between the track bed and the structure. The damper has two upright rigid concrete plates defining a vertical gap between them, and an elastic mat sandwiched between the concrete plates and in contact therewith.

Control of ground-borne noise and vibration

Ground-borne noise and vibration created by train operations is one of the major environmental problems faced by rail transit systems. In the past 10–20 years there have been a number of developments in the control and prediction of ground-borne noise and vibration although it is evident that further research is needed. In this paper the focus is on two methods of controlling the vibration radiated by the transit structure. First is the use of floating slab trackbeds, a method that has proven to be very effective at reducing vibration at frequencies above the resonance frequency of the floating slab system. Second is to modify the design of transit car bogies such that the wheel/rail forces are reduced. Although this method is still in the exploratory phase it has been shown that proper design of the bogie suspension can significantly reduce the levels of ground-borne noise and vibration.

Ground-borne noise and vibration from underground rail systems

Ground-borne noise is one of the main causes of environmental impact from urban rail transit systems. The vibration resulting from track-train interaction is transmitted through the tunnel 3tructure and the surrounding ground to adjacent buildings. The resulting vibrations of the walls and floors of these buildings cause secondary radiation of noise. This paper presents a method for estimating A-weighted sound levels as well as noise and vibration spectra due to ground-transmitted vibration in buildings near subways.

Ground-borne noise and vibration study—Toronto Transit Commission Yonge Street Northern Extension

Following construction of the Toronto Transit Commission Yonge Subway Northern Extension (YSNE), train operations created ground-borne noise and vibration which seemed unusually noticeable in buildings near the tunnel. This paper will briefly summarize some of the conclusions of an extensive study and measurement program that was undertaken to evaluate both the characteristics of the ground-borne vibration and various procedures for reduction of the vibration and noise. The measurements included tests intended to: (1) determine the characteristics of the ground-borne vibration and noise from the transit trains operating in YSNE tunnels, and (2) evaluate the effectiveness of design features and modifications to the facilities and transit cars in minimizing and reducing the noise and vibration. Some of the specific methods of controlling ground vibration include; use of resilient wheels, reduction of the rail fastener elastomer pad stiffness to decrease the coupling between the rail and the subway invert, grinding the rail, and turning the wheels. The vibration was measured at the tunnel invert, ground surface, and the walls and floors of adjacent buildings. In addition the interior noise induced by the ground-borne vibration was measured and analyzed.