scholarly journals Transmission of Railway Induced Vibrations in Buildings

2020 ◽  
Vol 320 ◽  
pp. 00003
Author(s):  
Mariya Moskovets ◽  
Nikolay Kanev
Keyword(s):  
Significant Influence ◽  
Acoustic Waves ◽  
Rail Transport ◽  
Building Structures ◽  
Protection Measures ◽  
Vibration Transmission ◽  
Transmission Coefficients ◽  
Vibration Protection ◽  
Building Foundation ◽  
Mechanical Resonances

This paper presents the problem of vibration transmission in building structures, which is induced by rail transport, and it discusses the effect of acoustic isolation used at the foundation. The vibration sources generate acoustic waves which are transmitted to the foundation and propagate trough the floors and slabs of the building. The transmission coefficients of the acoustic waves induced by metro trains and trams were determined in the building foundation and slabs. It was shown that mechanical resonances have a significant influence on the vibrations of the slabs. The characteristics of vibration propagation through vibration-insulated floors were found. Using the data obtained in this study, vibration effects in buildings located near vibration sources can be estimated, vibration protection measures can be developed.

scholarly journals Assessment of Rail Vibration Transmission from the Ground to the Foundation of a Building

2020 ◽  
Vol 320 ◽  
pp. 00005
Author(s):  
Mariya Moskovets ◽  
Nikolay Kanev
Keyword(s):  
Experimental Data ◽  
Field Measurement ◽  
Ground Surface ◽  
Vertical Direction ◽  
Rail Transport ◽  
Protection Measures ◽  
Foundation Slab ◽  
Vibration Transmission ◽  
Measurement Results ◽  
Vibration Parameters

This paper presents the problem of rail transport vibration transmission from the ground to building foundations. Field measurement results of vibration parameters on the ground near buildings and their foundations have been covered in this study. It has been shown that vibrations at the foundation of a building are much smaller than vibrations on the ground. The most intense vibrations on the foundation slab occur in the vertical direction. Comparison with other experimental data on vibration transfer from the ground to buildings structures has been made. The data obtained can be utilized in designing vibration protection measures and to analytically predict vibration effects in buildings. This analysis can be performed after measuring the vibration of rail transport on the ground surface.

TECHNICAL SEISMICITY AND STRUCTURAL NOISE SPREADING FROM TRANSPORT - THEIR INFLUENCE ON BUILDINGS CONSTRUCTIONS

Akustika ◽  
2020 ◽  
Vol 36 (36) ◽  
pp. 35-45
Author(s):  
Jana Dolejší ◽  
Jan Dolejší
Keyword(s):  
Urban Areas ◽  
Rail Transport ◽  
Building Construction ◽  
Building Structures ◽  
Structural Noise ◽  
Railway Tunnel ◽  
Noise And Vibration ◽  
Influence Of Noise

This paper deals with the influence of noise and vibration sources from which vibrations propagate through subsoil into building structures. Structural noise is usually then emitted by building structures into interiors. Especially within city centers and urban areas the approach of building construction towards sources such as road and rail transport differ in particular, whether the objects are located directly above the metro or railway tunnel, or objects close to roads or railways.

scholarly journals Reflection and Transmission of Acoustic Waves through the Layer of Multifractional Bubbly Liquid

2018 ◽  
Vol 148 ◽  
pp. 15001
Author(s):  
Damir Anvarovich Gubaidullin ◽  
Ramil Nakipovich Gafiyatov
Keyword(s):  
Acoustic Waves ◽  
Wave Reflection ◽  
Water Model ◽  
Bubbly Liquid ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
Multilayer Medium ◽  
Bubble Layer ◽  
The Mathematical Model ◽  
Theoretical Results

The mathematical model that determines reflection and transmission of acoustic wave through a medium containing multifractioanl bubbly liquid is presented. For the water-water with bubbles-water model the wave reflection and transmission coefficients are calculated. The influence of the bubble layer thickness on the investigated coefficients is shown. The theory compared with the experiment. It is shown that the theoretical results describe and explain well the available experimental data. It is revealed that the special dispersion and dissipative properties of the layer of bubbly liquid can significantly influence on the reflection and transmission of acoustic waves in multilayer medium

scholarly journals A proof that multiple waves propagate in ensemble-averaged particulate materials

2019 ◽  
Vol 475 (2229) ◽  
pp. 20190344 ◽  
Author(s):  
Artur L. Gower ◽  
I. David Abrahams ◽  
William J. Parnell
Keyword(s):  
Acoustic Waves ◽  
Volume Fraction ◽  
Effective Medium Theory ◽  
Effective Medium ◽  
Inhomogeneous Material ◽  
Ensemble Averaging ◽  
Reflection And Transmission ◽  
Medium Theory ◽  
Transmission Coefficients ◽  
Cylindrical Inclusions

Effective medium theory aims to describe a complex inhomogeneous material in terms of a few important macroscopic parameters. To characterize wave propagation through an inhomogeneous material, the most crucial parameter is the effective wavenumber . For this reason, there are many published studies on how to calculate a single effective wavenumber. Here, we present a proof that there does not exist a unique effective wavenumber; instead, there are an infinite number of such (complex) wavenumbers. We show that in most parameter regimes only a small number of these effective wavenumbers make a significant contribution to the wave field. However, to accurately calculate the reflection and transmission coefficients, a large number of the (highly attenuating) effective waves is required. For clarity, we present results for scalar (acoustic) waves for a two-dimensional material filled (over a half-space) with randomly distributed circular cylindrical inclusions. We calculate the effective medium by ensemble averaging over all possible inhomogeneities. The proof is based on the application of the Wiener–Hopf technique and makes no assumption on the wavelength, particle boundary conditions/size or volume fraction. This technique provides a simple formula for the reflection coefficient, which can be explicitly evaluated for monopole scatterers. We compare results with an alternative numerical matching method.

scholarly journals Methods of Noise and Vibration Protection on Urban Rail Transport

2017 ◽  
Vol 189 ◽  
pp. 829-835 ◽  
Author(s):  
E.P. Dudkin ◽  
L.A. Andreeva ◽  
N.N. Sultanov
Keyword(s):  
Rail Transport ◽  
Noise And Vibration ◽  
Vibration Protection ◽  
Urban Rail

Economic Comparison of Fire Fighting Measures of Gypsum-Based Materials

2016 ◽  
Vol 835 ◽  
pp. 467-471
Author(s):  
Marcela Halirova ◽  
Radek Janousek ◽  
Hana Sevcikova ◽  
Radek Fabian ◽  
Eva Machovcakova
Keyword(s):  
Fire Protection ◽  
Technology Implementation ◽  
Fire Risk ◽  
Steel Structures ◽  
Point Of View ◽  
Building Structures ◽  
Protection Measures ◽  
Economic Point ◽  
The Cost ◽  
Economic Comparison

Fire resistance of building structures is important not only in terms of prevention of hazards to human health, but also from the economic point of view. The choice of method of fire protection of steel structures depends on the responsible choice of finish or cladding material and suitable technology implementation. Although the assessment of fire risk is a priority, when selecting the decisive criteria we must not also forget the cost of fire protection measures. This article aims at economic comparison of the two fire protection measures for the steel column of rolled profiles.

TIME REDUCTION DURING RESTORATION OF THE EXTERIOR OF A HISTORICAL BUILDING

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Renato Lagana
Keyword(s):  
Execution Time ◽  
Subsequent Development ◽  
Second Phase ◽  
Building Structures ◽  
Construction Site ◽  
Urban Centers ◽  
Historical Building ◽  
Protection Measures ◽  
Long Time

Emergency management due to partial collapse of facade elements is a great interest topic. The collapse often occurs in unexpected damage to building structures of architectural value within the historic urban centers. The actions often require a long time to implement. After an initial delimitation and isolation of the damaged surfaces are initiated, discovery and design of the restoration are started. The economic coverage, no less important, is often done over the years. We undertake a case study, developed in the intervention performed in front of the Cathedral of Reggio Calabria. The study covered aspects related to the organization of the first measures after the collapse of some decorative elements and the subsequent development of the site. The first phase involved the organization and implementation of protection measures to achieve tight deadlines to allow the use of space for an important and non-deferrable event. Authorization procedures for this first phase were expedited and operating procedure for the management of safety for temporary installations was established. The second phase, managed in a day, involved the intervention to ensure the practicability and ensure the safety of users. The preparation of the construction site optimized the execution time of the procedures. The design of the temporary works optimized the work of the teams involved in work sequencing, which resulted in reduced downtime and possible interference. The result of the design choices and operational programming optimized the execution time.

scholarly journals Interaction acoustic waves with a layered structure containing layer of bubbly liquid

2018 ◽  
Vol 148 ◽  
pp. 15006
Author(s):  
Damir Gubaidullin ◽  
Anatolii Nikiforov
Keyword(s):  
Acoustic Waves ◽  
Theoretical Study ◽  
Bubbly Liquid ◽  
Air Bubbles ◽  
Angle Of Incidence ◽  
Natural Oscillations ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
Gel Layer ◽  
Transmission And Reflection

The results of a theoretical study of the effect of a bubble layer on the propagation of acoustic waves through a thin three-layered barrier at various angles of incidence are presented. The barrier consists of a layer of gel with polydisperse air bubbles bounded by layers of polycarbonate. It is shown that the presence of polydisperse air bubbles in the gel layer significantly changes the transmission and reflection of the acoustic signal when it interacts with such an obstacle for frequencies close to the resonant frequency of natural oscillations of the bubbles. The frequency range is identified where the angle of incidence has little effect on the reflection and transmission coefficients of acoustic waves.

scholarly journals Influence of vibration impacts from vehicles on the state of the foundation structure of a residential building

2019 ◽  
Vol 135 ◽  
pp. 03053
Author(s):  
Tatiana Zolina ◽  
Natalya Kupchikova
Keyword(s):  
Seismic Waves ◽  
Soil Layer ◽  
Experimental Studies ◽  
Residential Building ◽  
Structural Type ◽  
The State ◽  
Building Structures ◽  
Factors Affecting ◽  
Building Foundation ◽  
Foundation Structure

In this work, experimental studies were conducted on the effect of vibrational influences from highways on the state of the foundation structures of a five-story residential building in Astrakhan. The studies were combined with an examination of the geo-base, foundations, and foundation of a multi-story brick residential building. Studies have shown that over four years, damaged building structures underwent significant changes due to increased vibration from the highway, and the rate of deformation in the supporting structures prove their emergency state. It is confirmed that the main factors affecting the magnitude of vibration acceleration of the building foundation structure are: structural type of the building; distance from the building to the source of seismic waves; longitudinal wave propagation velocity in the soil layer.

Experimental observation of resonant filtering in a two-dimensional phononic crystal waveguide

2005 ◽  
Vol 220 (9-10) ◽  
Author(s):  
Jerôme O. Vasseur ◽  
Pierre A. Deymier ◽  
Maxime Beaugeois ◽  
Yan Pennec ◽  
Bahram Djafari-Rouhani ◽  
...  
Keyword(s):  
Transmission Spectrum ◽  
Acoustic Waves ◽  
Theoretical Calculations ◽  
Phononic Crystal ◽  
Stop Band ◽  
Side Branch ◽  
Two Dimensional ◽  
Transmission Coefficients ◽  
The Waves ◽  
Model Structures

AbstractTransmission of acoustic waves through a two-dimensional composite material made of PVC cylinders surrounded by air is measured experimentally. The spectrum presents a very large absolute band gap in the audible frequency range. A waveguide created inside this phononic crystal by removing a row of cylinders can transmit very efficiently the waves falling inside the stop band. We show the existence of deaf modes in the band structure of the linear waveguide. Resonant filtering is also demonstrated experimentally by coupling the waveguide to a side branch resonator of variable length. Frequency filtering is observed in the form of narrow dips in the transmission spectrum of the waveguide. Most of these observations compare favorably with theoretical calculations of dispersion curves and transmission coefficients of model structures using the plane wave expansion and the finite difference time domain methods. Narrow dips similar to those of the guide with resonator are also observed in the transmission spectrum of a waveguide with a sharp bend.

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