1) The document describes an antivibration pavement constructed using rubber mats made from recycled tires to reduce vibrations transmitted to nearby historical buildings from road traffic.
2) Measurements were taken of vibrations before and after construction using a digital tromometer at four points where a mass was dropped.
3) Analysis showed reductions in peak vibration amplitudes in both the time and frequency domains, indicating increased damping, with most improvement in horizontal directions. Some amplification remained in the vertical direction likely due to issues with mat installation.
Numerical Modelling of the Dynamic Behaviour of a Soil in True Triaxial Tests...Joao Rio
The study of soil's small strain dynamic behaviour was the main goal of this dissertation, for the case of a residual soil from Porto granite, a geotechnical material that possess a complex mechanic behaviour. To that end, a detailed experimental research was developed, in true triaxial conditions, considering the measurement of seismic wave velocities through bender elements.
A three-dimensional numerical model was produced that characterized the behaviour of this particular residual soil using a finite difference program, FLAC3D. Its main advantages reside in its simplicity, versatility and the possibility of directly measuring seismic wave velocities, not only in the three principal directions, but also in inclined directions.
This study requires the implementation of bender elements in the platens of the true triaxial apparatus, in order to assess the influence of its cubical geometry and boundary conditions (rigid or flexible platens, or even reflective and absorbent), as well as the validation of stiffness parameters attained from the measurement of seismic waves.
For this purpose, a series of parametric and sensitivity studies were developed, considering the linear elastic constitutive model, with isotropic loading, in the previously mentioned software, to particularly evaluate the influence of each parameter in the numerical modelling of the true triaxial apparatus, and which values are better suited for its correct representation. These parameters are: time step, amplitude, frequency, damping, Poisson’s ratio and finally, boundary conditions and a cross-anisotropic constitutive model. With these studies completed, a comparison and validation between the numerical results attained and the laboratory results previously done by Ferreira (2009), regarding residual soil specimens from Porto granite was in order. Due to time limitations, only the dry specimens (w ≈ 0%), namely, R8D-TT and R4D-K0TT were used in this comparative study.
Chances are you'll never have enough money to do all the things you'd like, so it is imperative that you budget. Budgeting is a matter of discipline an it is a skill that can be learned. Pay attention to every cent that is spent and plan all your activities and expenditure.
Numerical Modelling of the Dynamic Behaviour of a Soil in True Triaxial Tests...Joao Rio
The study of soil's small strain dynamic behaviour was the main goal of this dissertation, for the case of a residual soil from Porto granite, a geotechnical material that possess a complex mechanic behaviour. To that end, a detailed experimental research was developed, in true triaxial conditions, considering the measurement of seismic wave velocities through bender elements.
A three-dimensional numerical model was produced that characterized the behaviour of this particular residual soil using a finite difference program, FLAC3D. Its main advantages reside in its simplicity, versatility and the possibility of directly measuring seismic wave velocities, not only in the three principal directions, but also in inclined directions.
This study requires the implementation of bender elements in the platens of the true triaxial apparatus, in order to assess the influence of its cubical geometry and boundary conditions (rigid or flexible platens, or even reflective and absorbent), as well as the validation of stiffness parameters attained from the measurement of seismic waves.
For this purpose, a series of parametric and sensitivity studies were developed, considering the linear elastic constitutive model, with isotropic loading, in the previously mentioned software, to particularly evaluate the influence of each parameter in the numerical modelling of the true triaxial apparatus, and which values are better suited for its correct representation. These parameters are: time step, amplitude, frequency, damping, Poisson’s ratio and finally, boundary conditions and a cross-anisotropic constitutive model. With these studies completed, a comparison and validation between the numerical results attained and the laboratory results previously done by Ferreira (2009), regarding residual soil specimens from Porto granite was in order. Due to time limitations, only the dry specimens (w ≈ 0%), namely, R8D-TT and R4D-K0TT were used in this comparative study.
Chances are you'll never have enough money to do all the things you'd like, so it is imperative that you budget. Budgeting is a matter of discipline an it is a skill that can be learned. Pay attention to every cent that is spent and plan all your activities and expenditure.
Personajes que fueron importantes en la cultura vallenata y que con sus legados se despierta el sentimiento por conservar y defender las raíces ancestrales de un pueblo, Colombia
Finance is the source of many conflicts in relationships. If you can manage your family's finances then you are on your way to having a healthier relationship.
Hydrogen fuel cell vehicles are zero emission and run on compressed hydrogen fed into a fuel cell "stack" that produces electricity to power the vehicle. A fuel cell can be used in combination with an electric motor to drive a vehicle – quietly, powerfully and cleanly.
In the material testing laboratory, Tensile test was done on a mild steel specimen as figure 4 to identify the young’s modulus, ultimate tensile strength, yield strength and percentage elongation. The results were as table 1
TINCE2016 - Estimate of cracking and leaking rate of VERCORS mock-up - R. Vé...Gildas POTIN
The VERCORS project (French acronym for “Realistic verification of the behaviour of reactor containments”) consists in designing and building a 1/3 scaled mock-up of the inner containment of a French nuclear reactor of type “P’4”. The mock-up is a prestressed-concrete building dedicated to research purposes. Its overall dimensions are: height 25 m, diameter 15m, thickness of cylinder wall 0.40 m.
A first benchmark was organized by EDF with three themes proposed:
1. Early-age behaviour of gusset zone of the containment;
2. Containment history: prediction of deformations, stresses and cracking history of the whole containment during prestressing and first pressure test;
3. Leakage: estimate of air leakage during pressure test at the pressure peak of 5,2 bars absolute
The paper deals with calculations carried out by Tractebel Engie – Coyne et Bellier for themes 2 and 3. As regards results, we focus on cracking and leaking rate.
https://www.youtube.com/watch?v=62hr9HHZS14
I would like to articulate deep gratitude and veneration to Dr. Ashwani Jain, Professor, Department of Civil engineering for giving me opportunity to choose topic for seminar by my own. Last but not the least, thanks to our lord almighty for believing in me and gifting me such a utopia.
Geosynthetics have become well established construction materials for geotechnical and environmental applications in most parts of the world. Because they constitute manufactured materials, new products and applications are developed on a routine basis to provide solutions to routine and critical problems alike. Results from recent research and from monitoring of instrumented structures throughout the years have led to new design methods for different applications of geosynthetics. Because of the significant breath of geosynthetic applications, this report focuses on testing of geosynthetics products which would be more helpful in applications and design methodologies for reinforced soil and environmental protection works.
Personajes que fueron importantes en la cultura vallenata y que con sus legados se despierta el sentimiento por conservar y defender las raíces ancestrales de un pueblo, Colombia
Finance is the source of many conflicts in relationships. If you can manage your family's finances then you are on your way to having a healthier relationship.
Hydrogen fuel cell vehicles are zero emission and run on compressed hydrogen fed into a fuel cell "stack" that produces electricity to power the vehicle. A fuel cell can be used in combination with an electric motor to drive a vehicle – quietly, powerfully and cleanly.
In the material testing laboratory, Tensile test was done on a mild steel specimen as figure 4 to identify the young’s modulus, ultimate tensile strength, yield strength and percentage elongation. The results were as table 1
TINCE2016 - Estimate of cracking and leaking rate of VERCORS mock-up - R. Vé...Gildas POTIN
The VERCORS project (French acronym for “Realistic verification of the behaviour of reactor containments”) consists in designing and building a 1/3 scaled mock-up of the inner containment of a French nuclear reactor of type “P’4”. The mock-up is a prestressed-concrete building dedicated to research purposes. Its overall dimensions are: height 25 m, diameter 15m, thickness of cylinder wall 0.40 m.
A first benchmark was organized by EDF with three themes proposed:
1. Early-age behaviour of gusset zone of the containment;
2. Containment history: prediction of deformations, stresses and cracking history of the whole containment during prestressing and first pressure test;
3. Leakage: estimate of air leakage during pressure test at the pressure peak of 5,2 bars absolute
The paper deals with calculations carried out by Tractebel Engie – Coyne et Bellier for themes 2 and 3. As regards results, we focus on cracking and leaking rate.
https://www.youtube.com/watch?v=62hr9HHZS14
I would like to articulate deep gratitude and veneration to Dr. Ashwani Jain, Professor, Department of Civil engineering for giving me opportunity to choose topic for seminar by my own. Last but not the least, thanks to our lord almighty for believing in me and gifting me such a utopia.
Geosynthetics have become well established construction materials for geotechnical and environmental applications in most parts of the world. Because they constitute manufactured materials, new products and applications are developed on a routine basis to provide solutions to routine and critical problems alike. Results from recent research and from monitoring of instrumented structures throughout the years have led to new design methods for different applications of geosynthetics. Because of the significant breath of geosynthetic applications, this report focuses on testing of geosynthetics products which would be more helpful in applications and design methodologies for reinforced soil and environmental protection works.
Position Determination of an Aircraft Using Acoustics Signal ProcessingIJMER
This paper deals with the determination of an aircraft position using the acoustic source
emitted from it. As per the experimental setup, sound energy emitted from the aircraft is captured with
the help of microphones and processed further using MATLAB toolbox and LABVIEW software.
Localization algorithm is sub divided into two categories, in which the first method involves time delay
estimation of acoustic source through simulation process and the second method is analyzing the
Doppler frequency shift from the aircraft sound. Using the above methods the navigation parameters
such as velocity, Height, Mach number, RPM of the propeller, Elevation angle and slant range will be
determined.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Numerical Investigation of Jet Noise Prediction in Exhaust Nozzle by Passive ...IJERA Editor
The project mainly focuses on the reduction of jet noise emission in the exhaust nozzle of TURBOFAN ENGINES. Reduction of noise in the exhaust system is done by attaching chevrons with particular parameters in the nozzle exit. Numerical investigations have been carried out on chevron nozzles to assess the importance of chevron parameters such as the number of chevrons like (chevron count), chevron penetration and the mixing characteristics of co flow jet. Chevron count is the pertinent parameter for noise reduction at low nozzle pressure ratios, whereas at high nozzle pressure ratios, chevron penetration is crucial. The results illustrate that by careful selection of chevron parameters substantial noise reduction can be achieved. The sound pressure level (SPL) can be calculated from that we determined the noise level at nozzle exit section. After assessing the chevron parameters we are going to modify the chevron shapes in order to get maximum noise reduction along with very negligible thrust loss. Modification of chevron is based on aspect of increasing the mixing of cold jet and the hot jet in order to decrease the noise emission. ANSYS-Fluent is a commercial CFD code which will be used for performing the simulation and the simulation configuration contains three different velocities (100,150,200) with two different nozzle model(plain & chevron nozzle). The simulation results are evaluated to find out nozzle noise level in the engine exhaust system.
Numerical Investigation of Jet Noise Prediction in Exhaust Nozzle by Passive ...IJERA Editor
The project mainly focuses on the reduction of jet noise emission in the exhaust nozzle of TURBOFAN ENGINES. Reduction of noise in the exhaust system is done by attaching chevrons with particular parameters in the nozzle exit. Numerical investigations have been carried out on chevron nozzles to assess the importance of chevron parameters such as the number of chevrons like (chevron count), chevron penetration and the mixing characteristics of co flow jet. Chevron count is the pertinent parameter for noise reduction at low nozzle pressure ratios, whereas at high nozzle pressure ratios, chevron penetration is crucial. The results illustrate that by careful selection of chevron parameters substantial noise reduction can be achieved. The sound pressure level (SPL) can be calculated from that we determined the noise level at nozzle exit section. After assessing the chevron parameters we are going to modify the chevron shapes in order to get maximum noise reduction along with very negligible thrust loss. Modification of chevron is based on aspect of increasing the mixing of cold jet and the hot jet in order to decrease the noise emission. ANSYS-Fluent is a commercial CFD code which will be used for performing the simulation and the simulation configuration contains three different velocities (100,150,200) with two different nozzle model(plain & chevron nozzle). The simulation results are evaluated to find out nozzle noise level in the engine exhaust system
- Prepared a 2D stick model of the bridge in SAP2000 using the properties mentioned in the FHWA Bridge document
- Designed the bridge for linear and non-linear structural models to conduct analyses
- Performed different analyses on the bridge – multimode analysis, pushover analysis, time history analysis and capacity spectrum analysis
- Compared the shear force, bending moment, axial force and displacement values for each abutment and pier from all analyses and critically assessed the bridge performance
Concentrated dispersion & emulsion stability and instability analysis.
Formulation and quality control of
• emulsions
• suspensions
• foams
The TurbiScan MA 2000 is designed as a formulation and a product
stability control tool. The early stage detection allows to quickly correct
formulations and to shorten ageing tests.
The kinetic analysis visualisation is the only way to document stability studies in an easy to interpret format. Providing information about the mechanisms involved in a destabilisation, the TurbiScan MA 2000 allows to fully understand these physical processes and to apply the proper correction to the formulation.
Further informations there : http://www.formulaction.com/stability-turbiscan-classic.html
Similar to Master's degree final dissertation (20)
1. Università degli studi della BasilicataUniversità degli studi della Basilicata
FACOLTÀFACOLTÀ DIDI INGEGNERIAINGEGNERIA
Corso di Laurea in Ingegneria CivileCorso di Laurea in Ingegneria Civile
Dipartimento di Architettura, Pianificazione ed Infrastrutture di TrasportoDipartimento di Architettura, Pianificazione ed Infrastrutture di Trasporto
CONSTRUCTION OF ROADS, RAILWAYS AND AIRPORTSCONSTRUCTION OF ROADS, RAILWAYS AND AIRPORTS
FinalFinal dissertationdissertation
AntivibrationAntivibration pavements for the protection of historical heritagepavements for the protection of historical heritage
and public buildingsand public buildings
SUPERVISOR:SUPERVISOR:
Ch.moCh.mo Prof. Ing. M.Prof. Ing. M. AgostinacchioAgostinacchio
ASSISTANT SUPERVISORS:ASSISTANT SUPERVISORS:
Dott. Ing. G.Dott. Ing. G. CuomoCuomo
Dott. Ing. M.Dott. Ing. M. VonaVona
Dott. Ing. R.Dott. Ing. R. DitommasoDitommaso
CANDIDATE:CANDIDATE:
MarioMario MetastasioMetastasio
MatrMatr. 29442. 29442
2. TargetTarget
Realization of an antivibration hot-mix pavement to assure:
1) Softening of mechanics waves produced by vehicles
public
historical
nearby buildings such as:
2) Environmental safety ,using:
cultural
generating
RubberRubber matsmats fromfrom recycledrecycled tyrestyres
“noise”
exterior and structural
damages
4. ElementaryElementary SchoolSchool “San Giovanni“San Giovanni
Bosco” Via Verdi, Potenza.Bosco” Via Verdi, Potenza.
I)I) ChoiceChoice ofof thethe workingworking sitesite
Structural characteristics:
- The 40’s;
- Reinforced concrete structure;
- Four floors;
- Rectangular scheme.
5. II)II) DesigningDesigning ofof thethe pavementpavement
Total gauge of the antivibration pavement: 8,5 cm
BinderBinder,,
In hot-mix (4,0cm)
Overlapping of three layers:
In hot-mix (4,0cm)
Base,Base,
in granular mixture (3,0cm)
AntivibrantAntivibrant,
in rubber mats (1,5cm)
Preexisting foundations layer
6. MaterialsMaterials
Rubber mat from recycled tyres
ToTo assureassure thethe softeningsoftening ofof thethe
oscillationsoscillations generatedgenerated byby aa
hittinghitting mass on themass on the pavementpavement
Length 1,25 m
Wide 1,00 m
Gauge 0,015 m
Density 730 Kg/m3
∆ Lnw = 21 dB (UNI 140/8)
nudo
ISOLRUBBERISOLRUBBER
Sound-proof
nudo
∆ Lnw = 37,5 dB (UNI
140/6) accoppiato
Compressive strength
2,4 Kg/cm2 deformazione
10% DIN 53421
Tensile strength
4,6 Kg/cm2 DIN EN ISO
1798
Elongation at break 40% DIN EN ISO 1798
Elasticity in compression 27,5 Kg/cm2
Determination of the stress-
strain characteristics in the
compression
CC25 = 599 Kpa
CC40 = 599 Kpa
CC50 = 599 Kpa
Dynamic stiffness 60 MN/m3
7. HOTHOT--MIXMIX
To realize the upper layer “BINDERONE”“BINDERONE”
Project curve
Apertura
Vaglia (mm)
40 31,5 22,4 16 11,2 8 5,6 4 2 1 0,1
Curva Progetto 100 100 100 99,47 84,28 80,17 55,26 47,11 32,26 21,98 6,01
Fuso di riferimento Dmax = 16 mm
secondo UNI Eni 13108
Apertura setacci (mm) 22,4 16 2 0,063
Passante percentuale 100 100 50 12
Passante percentuale 100 90 10 0
Percentages of use
Percentuage of bitumen
Riferita al peso degli
inerti
4.80%
Riferita al peso della
miscela
4.58%
Fattore correttivo α 0.98
Massa volumica 2.69 Mg/mc
Costante 2.65
Contenuto minimoPercentages of use
Sabbia 0-4 Aggregato 2-8 Aggregato 10-16 Aggregato 14-22
36 45 19 0
Contenuto minimo
di legante
4.48%
Categoria Bmin 4.4
8. BITUMINOUS EMULSION
To improve and assure the cohesion within
UpperUpper layerlayer
LowerLower layerlayer
ANIONIC BITUMINOUS EMULSIONANIONIC BITUMINOUS EMULSION
Carattesristiche Metodo di prova Valori
Contenuto di acqua [%] NF-T 66-023 43<47
Contenuto di fluss. [%] C.N.R. n 100 1<3
Viscosità E a 20 C NF-T 66-020 5<8
Omogeneità a 630 [μ] NF-T 66-016 <0.2
GRANULAR MIXTURE Omogeneità a 160 [µ] NF-T 66-016 <0.25
Sedimentazione a 5 gg. C.N.R. n 124 ≤5
Indice di rottura NF-T 66-017 <98
Carica delle particelle NF-T 66-021 positiva
pH (grado di acidità) procedura interna 1012
CHARACTERISTICS OFTHE BINDERCHARACTERISTICS OFTHE BINDER
Penetrazione a 25 C
[dmm]
EN 1426 70<220
Viscosità a 160 C [Pa.s-
1]
EN 2595 0.060<0.160
Punto di rammollimento
[ C]
EN 1427 35<46
Punto di rottura (Fraass)
[ C]
EN 12593 <-10
GRANULAR MIXTURE
For the lower layer has been used the
milled from preexisting pavement
9. III) Laying of the pavement
Size of the pavement
Size of the surface covered in rubber mats
4,55 m
25,00 m
4,00 m
20,00 m
14. 5° stage:
Clening-up of the working area and laying of the rubber mats from recycled tyres
Size of the area for the rubber mats
4,00m x 20,00m
Size of the scarificated area
4,55m x 25,00m4,55m x 25,00m
Wide: 4 raws of rubber mats without covering 0,55m To assure softening
properties
Length: 16 raws of rubber mats without covering 5,00m
To laying the
bituminous emulsion
15. 6° stage:
Laying of the base layer made of granular mixture
Gauge: 3 cm
Reuse of the milled layer
sprinkled by workers
compacted by a roller
deposited by a digger
16. 77°° stage:stage:
Laying and compaction of the binder layer (4cm)
Reopening of the road after
scattering accross the bituminous
emulsion by workers
17. IV) Measurements ante-post operam
DigitalDigital TromometroTromometro
It measures seismic amplification on surface but for this test we have used it to measure
the vibrations on a building
Barycenter long side
of the building
North
Location of the instrument
of the building
Exit of the School
Three electrodynamic sensors (velocimeters N-S,
E-W, Z)
GPS system
Acquisition of noise data, amplified and digitized at 24 bit, with
programmable sampling frequency
512 Hz
18. Choice of 4 strike points for the hitting mass
Choice of 4 strike points where generating vibrations ante-post operam
Point 1
Point 2Point 3
In front of the instrument (5,50m)
To the right of the point 1
(5,00m)
To the left of the Point 1 (5,00m)
Point 4
In front of the instrument (10,00m)
19. Generation of the vibrations
Positioning of the hitting mass and generation of the vibrations
Mass: 10 kg Height of fall: 1,10 m
Weight lifting
Positioning
Falling of the mass
20. V) AnalysisAnalysis andand comparisoncomparison ofof measurementsmeasurements anteante--
postpost operamoperam..
Data analysis through
Time domain
Frequency domain
TIME DOMAIN ANALYSISTIME DOMAIN ANALYSIS
peak values of the oscillations ante-post operam
FREQUENCY DOMAIN ANALYSISFREQUENCY DOMAIN ANALYSIS
Spectral parameters Maximum value for Fourier’s spectrum
recorded on velocimeter tracks
Fourier’s spectruma area
This analysis has been conducted before and after the laying of the pavement
21. DataData analysisanalysis usingusing ““MatlabMatlab” (” (MathworksMathworks) software) software
Management of recorded data using
the database of “Grilla” software
Codified file in
file ASCII
Matlab data analysis in two stages:
11°° stage (stage (TimeTime domaindomain analysisanalysis))
Comparison of amplitude of the ascillations in the Time domain:
< ante-post operam;
< N-S, E-W, Z;
< 4 strike points;
< 10 strikes for each point.
22. Example
<Records, ante post operam , of the Time domain analysis for the first strike,
in strike point 2, in the three directions W-E,N-S e Z.
DAMPING FACTOR(ξ)
Stikes
W-E N-S Z
Ante Post Ante Post Ante Post
1 2,21 4,98 2,42 3,24 4,99 4,48
2 1,87 4,45 3,49 4,62 2,58 3,812 1,87 4,45 3,49 4,62 2,58 3,81
3 1,81 4,12 0,11 3,40 5,74 2,83
4 2,65 3,32 2,12 3,68 4,98 6,14
5 2,60 3,63 2,68 3,45 5,69 5,66
6 2,17 4,16 3,24 3,02 5,78 3,60
7 1,90 5,97 3,27 4,43 4,37 2,46
8 1,92 4,30 2,42 4,28 4,35 5,10
9 1,92 2,46 2,41 3,33 4,77 2,97
10 2,07 4,03 2,82 5,06 5,32 3,50
Mean 2,11 4,14 2,50 3,85 4,86 4,06
STD 0,30 0,94 0,95 0,69 0,96 1,25
23. <Trend of the peaks of the oscillations, Post/Ante operam ,
In Time domain, for strike points 1,2,3 e 4 in direction N-S
24. 2° stage (Frequency domain analysis)
A) Comparison between the amplitudes of the oscillations in Frequency domain:
Example:
< ante-post operam;
< W-E,N-S,Z;
< 4 strike points;
< 10 strikes for each point.
<Fourier’s<Fourier’s spectraspectra forfor thethe oscillationsoscillations, first strike, first strike forfor the strikethe strike pointpoint 11
25. <Trend of the peaks of the oscillations, Post/Ante operam ,
in Frequency domain, for strike points 1,2,3,4 in direction N-S.
26. B) Comparison between Fourier’s spectra areas:
< ante-post operam;
< W-E,N-S,Z;
< 4 strike points;
< 10 strikes for each point.
Example:
<Trend of Fourier’s spectra areas, Post/Ante operam, for strike points 1,2,3,4 in direction N-S
27. CONCLUSIONS
Comparing results , recorded ante-post operam, we have registered:
For each pulsepulse, this configuration reduces the length of the recording in the
configuration post-operam thanks to the increae of the damping factor;
This configuration significantly reduces the smaximum spectral amplitudeamplitude forfor thethe
componentscomponents inin thethe horizontalhorizontal planeplane;
There are increases of the values for the vertical component probably attributable to
problems related to the laying ot the rubber mats.
28. FUTURE DEVELOPMENTS
Improving the laying of the rubber mats:
It would be of considerable interest, not being in literature, realizing a correct protocol for
the laying of the rubber mats inside the road pavement;
It would be desiderable to be able to perform test in situ and in laboratory in order to
control all the variables for the real scale experimentt.
Improving the data analysis:
It would be interesting investigate the causes that generate the amplifications of the
maximum spectral amplitude for the vertical component in the plane;
Could be very interesting investigate a scheme to laying the rubber mats case by case in
order to reduce the amplifications which damage the buildings.