SUTIP2/C/QCBS/08-2015 Development of a bridge and tunnel...

SUTIP2/C/QCBS/08-2015

DevelopmentofabridgeandtunnellaboratoryattheGeorgianTechnicalUniversity

ADDITIONALASSIGNEMENT2:AROUNDOFMODELINGOFROADANDNOISEBARRIERCONSTRUCTION-RELATEDVIBRATIONIMPACTON9RESIDENTIALBUILDINGSIN

PHONICALA

DRC–DiagnosticResearchCompanyViaMontesicuro,60131,Ancona,Italy

SummaryINTRODUCTION.........................................................................................................................................................51. VIBRATIONS–IMPACTLEVELSANDSTANDARDS..............................................................................................7

STANDARDS...................................................................................................................................................................7UNI9916andDIN4150............................................................................................................................................7ISO4866...................................................................................................................................................................10

2. METHODOLOGICALAPPROACHANDINPUTDATA..........................................................................................15CENSUSOFBUILDINGSANDTHEIRSTRUCTURALCONFIGURATION............................................................................16HIGHWAYSECTIONSINCORRESPONDENCEOFBUILDINGSIMPACTED..........................................................................19DYNAMICCHARACTERISTICSOFSOIL..........................................................................................................................20TYPEOFEQUIPMENTUSEDINCONSTRUCTIONANDSPECTRAEMISSIONOFEQUIPMENTYARD.................................21SPREADOFVIBRATIONSBETWEENSOURCEANDRECEIVER........................................................................................25

Propagationofvibrationintheground..................................................................................................................26Propagationofvibrationinthestructureofthebuilding.......................................................................................27

4. VIBRATIONCAUSEDBYNEWROADCONSTRUCTIONWORKS.........................................................................29ANALYSISOFINDIVIDUALBUILDINGS..........................................................................................................................29CONCLUSIONSANDRECOMMENDATIONSONVIBRATIONCAUSEDBYNEWROADCONSTRUCTIONWORKS............31

5. VIBRATIONCOMINGFROMTHEOPERATIONOFTHENEWROAD...................................................................33ACQUISITIONOFVIBRATIONMEASUREMENTS...........................................................................................................34

Equipment...............................................................................................................................................................36AnalysisofacquiredData.......................................................................................................................................39

ANALYSISOFINDIVIDUALBUILDINGS..........................................................................................................................42CONCLUSIONSANDRECOMMENDATIONSONVIBRATIONCAUSEDBYNEWROADOPERATION................................43

6. VIBRATIONGENERATEDTHROUGHCONSTRUCTIONOFTHENOISEMITIGATIONSTRUCTURES.......................45NOISEMITIGATIONMEASURES...................................................................................................................................45ANALYSISOFINDIVIDUALBUILDINGS..........................................................................................................................51CONCLUSIONSANDRECOMMENDATIONSONVIBRATIONGENERATEDTHROUGHCONSTRUCTIONOFTHENOISEMITIGATIONSTRUCTURES...........................................................................................................................................56TOSUMMARIZETHEANALYSISPROVIDEDINTHISSECTION,THEFOLLOWINGMANDATORYRECOMMENDATIONSSHOULDBEMADE:.........56

7. SUMMARYTABLEOFALLFINDINGS................................................................................................................57REFERENCES............................................................................................................................................................588. ANNEXES........................................................................................................................................................59

ANNEX1:INPUTDATA(ENTEREDINTHEMODEL)..................................................................................................................59ANNEX2:RAWDATAOFMEASUREMENTSOFVIBRATIONFROMPRESENTDAYROAD–SEPARATEATTACHMENT.................................59ANNEX3:OUTPUTSOFMODELING(DATATABLES)...............................................................................................................59ANNEX4:FIELDINSTALLATIONBESTPRACTICESMANUAL,NATIONALPRECASTCONCRETEASSOCIATION,USA(NCPA)...................59ANNEX5:FHWAHIGHWAYNOISEBARRIERDESIGNHANDBOOK,U.S.DEPARTMENTOFTRANSPORTATION,FEDERALHIGHWAYADMINISTRATION,FHWA-EP-00-005DOT-VNTSC-FHWA-00-01,PB2000-105872...........................................................59ANNEX6:AILSOUNDWALLS,ENGINEERINGNOISEMITIGATIONSOLUTIONS(ANEXAMPLEOFINTERNATIONALBESTPRACTICES).....59

Investigation of Vibration Impact Phonichala, Tbilisi di 59

4


5

IntroductionThisreportreferstothestudycarriedouttoestimateandevaluatethevibrationsgeneratedbythe construction of the new highway and noise mitigation structures, as well as vibrationsgeneratedduringoperationofthehighway.This report supplements the earlier report Ambient vibration survey and dynamicidentificationofresidentialbuildingsPhonichala,Tbilisi -submittedonApril20,2017 thatmeasured thenatural frequenciesof the 9buildings in thePonichaladistrict Tbilisi. Thescopeoftheadditionalassignment2includesthestudyoftwosourcesofvibration:

- vibrationscausedbyconstructionworksofnewroadandnoisemitigationstructures;and- vibrationsgeneratedbytheoperationofthenewroad;

The report evaluates theeffectsof vibrations inducedbymachineriesused inconstructionofthe road during and operating activities on the buildings and voluntary annexes which arepotentiallymoreexposed;thelevelofvibrationsgeneratedbythetransitofvehiclesduringtheoperational phase of the road is also estimated; and the effects of vibration induced by theconstructionofnoisemitigationmeasures.TheinvestigatedstructuresarelocatedinPhonichaladistric,Tblilisi(Figures1and2.“Locationofbuildings”).

Figure1Locationofstudiedbuildings


6

Figure2Locationofstudiedbuildings

Themodellingandanalysisperformedhavebeenbasedonthecalculationmethodofpropagationofvibrationsbetweensourceandreceiver,consideringthedampingcharacteristicsofthegroundandthephenomenaofprimaryamplificationandattenuationwithinthebuilding.Thegenerationofvibrationsaredefinedbasedonexperimentaldatabasesfromsimilarworksinvolvingtheuseofall the categories of machinery necessary to complete the work. More details regarding themethodologyareprovidedinChapters2and3ofthisReport.


7

1. Vibrations–ImpactLevelsandStandardsIncaseswhenthevibrationimpact isconsideredasapotentialoractualrisk,significantimpactsare observedwhen sourcesof vibration generation are located relatively close to the buildings(usuallynomorethanafewtensofmeters).Theeffectsofvibrationsonbuildingscanvaryfromanuisancetopeople(whenthevibrationcanbesensedbutnoactualdamageoccurs)tostructuraldamages.Vibration sources such as construction activities and road traffic, are among the sourcesconsideredpotentiallydangeroustobuildingsandstructures.Ingeneralstructuraldamagestobuildingsareextremelyrareandareingeneralcausedbyothercauses.Structuraldamagesoccurwhenthepermissivelevelsofvibrationareexceeded.Degrees of damage are methodologically defined and vary from those that do not affect thestructural safetyof thebuildingsbutaffect thevalueofassets–e.g. formationof cracks in theplaster,increaseinexistingcracks,damageofarchitecturalelementsetc.TheclassificationofdamagecategoriesusedinanalysisofvibrationimpactsisdeterminedbyISO4866andisthefollowing:

- Damagethreshold:Formationofcracksonthesurfacesofthethread-likedrywall,increaseofexistingcracksontheplastersurfacesoronthesurfacesofdrystonewalls;alsocracksinthemortarjointsinthethread-likeconstructioninbrickandconcrete;

- Minor damage:Wideningofcracks,detachmentandfallofplasterorpiecesofplasterdrywall;formationofcracksinblocksofbrickorconcrete;

- Major damage: Damage of structural elements; cracks in the support columns; openingofjoints;setofcracksinmasonry.

In thepresentwork theeffectsof vibrations in termsofnuisance/annoyance topeoplearenotconsidered,andonlythepotentialdamagetostructuresareevaluated.

STANDARDS

UNI9916andDIN4150

The damage to buildings caused by vibrations are defined by UNI 9916 "Criteria formeasurement and evaluation of effects of vibrations on buildings", usually in substantialagreement with the technical content of ISO 4866 and DIN 4150. The standard providesguidanceon the choiceof appropriatemeasuringmethods,data processing andevaluationofthe vibratory phenomena in order to allow also the evaluation of the effects of vibrations onbuildings (risk of structural damage), with reference to their structural response and structural


8

integrity. According to the UNI 9916, the physical quantity which best represents vibratoryphenomenonisnottheacceleration,butthespeedreachedbythevibration.DIN4150distinguishbetweenshortduration(transient)andlongdurationphenomenaaccordingtothefollowingtables1and2.

Table1Referencevaluesforthespeedofvibrationinordertoevaluatetheactionofthevibrations

ofshortdurationonbuildings(DIN4150)

Note:“Frequencyranges(Hz)”refertothefrequencyrangesgeneratedbyvibrationsource.Foreachrange–differentvalues/rangesofvibrationspeedapply.Inanalysis,themostrestrictivevaluesofvibrationspeed(generatedatfrequencyrangeof<10Hz)wasapplied.

Category TypeofContructionSpeedofvibration(mm/s)

measurementatthelastfloor,allfrequencies

1 Buildingusedforcommercialpurposes,industrialbuildingsandsimilar 10

2 Residentialbuildingsandsimilar 5

3Buildingsverysensitivetovibrations,notincludedinthepreviouscategoriesandofgreatintrinsicvalue

2.5

Table2Referencevaluesforthespeedofvibrationinordertoevaluatetheactionofthevibrationsof longdurationonbuildings(DIN4150)

Understandably,forcoherenceandunquestionablecredibilityofthefindingsandanalysisofthisvibrationimpactverificationassignment,thekeyquestionsare:–Towhatcategorythecorebuildingsandannexestothese,takenseparately,belong?


9

–Becausedependingondurationofvibrationemmissions impactingthebuildingsthenatureofimpactandpermissivethresholdsaredifferent-whatkindofvibrationimpacts–LongorShortaretooccure?-and,–What are the permissive damage thresholds should be referred to in analysing and derivingconclusiononwhetherthevibrationswilldamagethebuildingsandtheannexes–whenfactoringina.categoryofbuildingsandb.typeofvibration?These parameters are clearly guided by methodological standards applied internationally andcannot and have not been set arbitrarily. Given the objective of this assignment, these threeimportantaspectsdeservemoredetailedexplanation.Categorization of buildings: Table 2 above contains building categorization determined by DIN4150– category 1: Commercial/Industrial buildings and similar; Category 2: Residential buildingand similar; andCategory 3: Sensitive buildings. Basedon the reviewof the structural integritydata and parameters derived by NEP Srl. as the result of a series of tests and analyses (e.g.concretesamplingandtesting,foundationsassessment,assessementofvoluntaryadditionsetc.)–themaincorepartsofallbuildingscanbesafelyassignedtoCategory2:Residentialbuildingandsimilar.Althoughmain/corepartsofthebuldingareofabout4decadesold,theyareinsufficientlygoodshapetonottobeconsideredundersensitivecategory.However,giventheimprovisedwayinwhichvoluntaryadditionsweredesignedanderectedwithnoreference tosounddesignandconstructionpractices,thesecertainlybelongtoCategory3:Sensitivebuildings.Shortor longvibrations: In caseof constructionof the roadandnoisemitigation structures,aswellasincaseofroadoperation,thebuildingswillbesubjecttoshortvibrationimpacts–impactsthatoccureforshortperiodoftime(e.g.theperiodoftimewhenrollercompactorisworkingorwhen a heavy vehicle is crossing in front of an impacted building). Characterization of Long(transitent) andShort vibrations isdefined inDIN4150-3.Nevertheless,only fordemonstrationpurpose, in comparison ofmodelled vibration impact to the damage thresholds, thresholds forboth–shortandlongvibrationimpactsbycategoryofbuildingsassignedtomain/corestructutresandtheannexes–havebeenreferred(asitcanbeseeninTables13,14,18and21).Damagethresholdlimitsappliedintheanalysis:Asit isshowedinTables1and2,accordingtoDIN4150,forCategory2:FResidentialbuildingsandsimilar(towhichmain/corebuildingsbelong),thethresholdforvibrationvelocityis5mm/sforboth–longandshortdurationvibrations.AsforCategory 3 Sensitive buildings (category for the Voluntary Additions), for short vibrations thethresholdis2.5mm/sandforlong–5mm/s.


10

Ifdesired,however,attributabletoasingleratingscaleindB,makingthenecessarycalculationsitturnsoutthatamonglevelsofweightedaccelerationandspeedlevelsexiststhefollowingrelation(thisforfrequencygreaterthanorequalto8Hz):

𝐿",$%& = 𝐿(,$%& − 29 (1)

𝐿(,$%& = 20𝑙𝑜𝑔 ((0

(2)

Where:𝑣2isthereferencevelocity,fixedat1045(mm/s)𝑣isthecurrentvelocity(mm/s)Theweightedaccelerationsaregivenby:

𝐿",$%& = 𝐿(,$%& − 29 = 20𝑙𝑜𝑔 67289

− 29 =105dB (3)

ThehighlightedfiguresinTable3arethevaluesofvibrationvelocity(mm/s)calculatedandexpressedindB.

Category TypeofConstructionsDurationofvibration

Velocity Levelmm/s dB

2 Residentialbuildingsandsimilar

short5 105



3 Buildingsverysensitivetovibrations

short3 100.5



3 Buildingsverysensitivetovibrations

long2.5 99

Table3Level l imitreferencetocompareforanalysis–accordingtoeffectiveDINStandards

ISO4866

Theprinciplesforcarryingoutvibrationmeasurementandprocessingdataregardingtheeffectsofvibration on structures are established by the International Standard ISO4866 “Mechanicalvibrationandshock,Vibrationoffixedstructures,Guidelinesforthemeasurementofvibrationsandevaluationoftheireffectsonstructures”.


11

The most common and frequent structural damage from man-made sources occurs in thefrequencyrangefrom1to150Hz.Naturalsources,suchasearthquakesandwindexcitation,usuallycontaindamage-levelenergyatlowerfrequencies,intherangefrom0,1Hzto30Hz.TheISO4866reportsseveralreferencevaluesofstructuralresponsesforvarioussources.Moreover this Standard provides simplified guidelines for classifying buildings according totheirprobablereactiontomechanicalvibrationtransmittedbytheground.TableB.2gives14simplifiedclassestakingintoconsiderationthefollowingfactors:a)typeofstructure(asascertainedfromTableB.1ofISOStandard);b)foundation(seeClauseB.5ofStandard);c)soil(seeClauseB.6ofStandard);d)“politicalimportance”factor.


12

TableB.1—Categorizationofstructuresaccordingtothebuildinggroup(ISO4866)

The buildings under exam belong to the subgroup in column 1, “ancient, historical or oldbuildings”.


13

In the present case, the category of foundation of buildings falls into “Class C” (see Table B.2), whichincludes the following types:

- lightretainingwalls;- largestonefooting;- stripfoundation;- platefoundation;- nofoundations(wallsdirectlybuiltonsoil).

The category of soil falls into “Type C” (see Table B.2), which includes horizontal bedded soils, poorly compacted firm and moderately firm non-cohesive soils, firm cohesive soils.

TableB.2—Classif icationofbuildingsaccordingtotheirresistancetovibrationandthetolerance

thatcanbeacceptedforvibrationaleffects(ISO4866)


14

AccordingtoStandards, ispossibleto identifytheclassofbuildings(TableB.2) foreachbuildingbeingexamined.The buildings belong to category 8 and 11, witch correspond to high degree of protectionrequired,asreportedinTable4.

Table4–classofbuildingsaccordngtoISO4866

2 1 6 C c 8

3 1 4 C c 11

4 1 4 C c 11

5a 1 4 C c 11

5b 1 4 C c 11

5c 1 4 C c 11

6 1 5 C c 11

7 1 6 C c 8

8 1 6 C c 8

9a 1 4 C c 11

9b 1 4 C c 11

10 1 6 C c 8

ClassofBuildingBuildingCode

GroupofBuilding

Categoryofstructure

CategoryofFoundations TypeofSoil


15

2. METHODOLOGICALAPPROACHANDINPUTDATAThestudywascarriedout toestimatevibrations induced inthereceptors (i.e.buildings)andtoevaluate its effects in terms of damage to buildings (UNI 9916, DIN 4150-3), analysing threedifferentconfigurations:

a) vibrationcausedbyworksofnewroadconstruction;b) vibrationcomingfromtheoperationofthenewroad;c) vibrationgeneratedbyconstructionofthenoisemitigationstructures.

Calculationsareperformedusingthefollowingproceduralsteps:

1) Identificationofbuildingspotentiallyimpacted(EPI);2) Analysisoftheconstructionprojectwithparticularattentiontothesectionsofthemotorway

nearbythebuildings;3) Analysisofthegeotechnical/dynamiccharacteristicsofthefoundationsoilsattheEPI;4) ListofheavymachineryusedintheconstructionofthemotorwayattheEPI;5) Analysisandadoptionofavailabledataconcerningthespectraofthevibrationsgeneratedby

theemployedconstructionmachines;6) Estimation of the level of vibrations, in order to evaluate the attenuation due to the

propagationofwavesintheground,theformulationsproposedintheliterature;7) Estimationofvibrationsinbuildingsbytheapplicationofthefunctions/algorithmsdescribingthe

propagationinthewave-pathfromthesourceofthetransferfunctionsoftheabovepoints;8) Evaluation of vibration levels set up in the EPI by comparison with the limits set by the

regulations;9) Identificationofcriticalissuesandpossiblemitigationmeasures.

The road constructionmethodand specificationsofequipment for the generationof vibrationssuchas theonesused forpiling, soil compacting andotherworks, are all known in advanceofconstructionphase. Traffic load levels for thenew roadby typeof vehicles is also known (dataprovided in engineering design documents provided by Dohwa). Thus, the levels of vibrationsduringtheroadconstructionandoperationcouldbedeterminedusingthemodel.In assessing vibration coming from the construction of the noisemitigation structures, in theabsenceofthedetaileddesign,safetythresholds/permissivelevelsofvibrationatthesourcepointsof potential vibrations derived by modelling, will be used to define the specifications andrecommendations about themethodology of construction and types of equipmentwhich areconsideredsuitablefortheworkintermsofgenerationofvibrations.


16

Thederivedlistofsuitableequipmentandmethodsoffoundations(piling,micropiling,beam,etc)willbe thebase for selectinganddesigningprecisemitigationmeasures for constructionworkswithoutcausingdamagetothebuildings.

CENSUSOFBUILDINGSANDTHEIRSTRUCTURALCONFIGURATION

The list of structures under investigation and the limit of the future motorway are shown inTables 5-6-7. In the tables theprogressivedistance changes along theurban road, the stateofconservation and the results of the dynamic investigation performed under Task 1 of thisAdditionalAssignment2(seecolumnDynamicData)areshown.

Table5summaryof investigatedbuilding,distancefromtheroadanddynamicdata

ModeNumber

Frequency(Hz)

Damping(%)

1 6.69 0.39

2 7.28 3.64

3 7.73 3.01

4 8.48 2.19

1 1.89 0.84

2 2.01 0.94

3 3.28 0.90

4 5.77 2.97

1 1.75 0.75

2 2.10 1.20

3 2.95 0.74

4 5.46 1.19

1 3.19 3.76

2 4.56 1.32

3 4.71 2.01

4 5.54 4.20

5aPrecastconcretepanel

Poor5ResidentialBuilding275Km+660

Poor9ResidentialBuilding19

Precastconcretepanel

Poor9ResidentialBuilding225Km+3703

5Km+4704

DynamicData

5Km+300 9Brickworkbysquaredstone

blocksPoor2

ResidentialBuilding

BuildingCode

2

TypesofConstruction

StateConservation

NumberofFloors

DestinationofUse

MinimumDistancefromtheRoad(m)

ProgressiveDistance(m)StructuralScheme


BLOCK 5A


17

Table6summaryof investigatedbuildings,distancefromtheroadanddynamicdata

ModeNumber

Frequency(Hz)

Damping(%)

1 2.98 0.36

2 4.53 1.48

3 4.75 1.41

4 6.63 0.82

1 3.05 2.42

2 4.52 4.51

3 4.86 1.52

4 5.68 3.72

1 3.33 1.08

2 3.85 1.89

3 4.05 0.62

4 4.97 1.02

1 5.17 3.23

2 6.06 2.22

3 6.35 2.44

4 6.75 1.28

27

DestinationofUse

NumberofFloors

StateConservation

TypesofConstruction

DynamicData


Poor5ResidentialBuilding


Poor5ResidentialBuilding

BuildingCode StructuralScheme

ProgressiveDistance(m)

MinimumDistancefromtheUrbanRoad(m)

7

6

5b

275Km+6605c

5Km+370

Brickworkbysolidbrickswithcement

mortar


5Km+660

5Km+780

Brickworkbysquaredstone

blocksPoor2

ResidentialBuilding52

BLOCK 5B

BLOCK 5C


18

Table7summaryof investigatedbuilding,distancefromtheroadanddynamicdata

Since all Buildings areused as residential units, the vibration values identified in the forecastingmodelhavetobecomparedtothethresholdsofreferenceforsuchtypeofbuildings.Buildingsareinaverypoorstateofmaintenance.Masonrybuildingsaremadeofblocksofstone,bricks andmortar; concrete buildings aremade by load bearing panels and reinforced concreteelements.

ModeNumber

Frequency(Hz)

Damping(%)

1 4.25 4.89

2 6.79 2.89

3 6.99 3.07

4 8.84 2.38

1 3.16 0.92

2 4.68 1.48

3 5.03 3.03

4 5.85 2.41

1 3.17 0.67

2 4.63 1.89

3 5.05 2.94

4 5.86 0.69

1 4.93 1.25

2 6.14 1.73

3 6.42 1.78

4 6.86 1.12

9a 5Km+520

DynamicData


BuildingCode StructuralScheme


MinimumDistancefromtheUrbanRoad(m)

5Km+5209b

8

10



DestinationofUse

NumberofFloors

StateConservation

TypesofConstruction


blocksPoor3

ResidentialBuilding875Km+600



blocksPoor2

ResidentialBuilding575Km+440

BLOCK 9A

BLOCK 9B


19

HIGHWAYSECTIONSINCORRESPONDENCEOFBUILDINGSimpacted

The following two sections of themotorway are representative of the typology of structure inproximityofthebuildingsofinterest.Asvisible,inproximityofbuildingsfrom1to10(excluding6)animportantembankmenthastobebuilt(Fig.3).Ontheotherhand,Section6(Fig.4)importantexcavationworksareneeded.

Figure3Cross-sectiononBuilding#2to#10(except#6)

Figure4Cross-sectiononBuilding#2to#10(except#6)


20

DYNAMICCHARACTERISTICSOFSOIL

Due to lateral homogeneityof the subsoil, theentirearea fromBuilding1 toBuilding6 can berepresentedbytheaveragevaluesshownbelow,obtainedbythegeotechnicalinvestigationsandgeophysicalmeasurements:

Table8Dynamicparametersofthesubsoil

where:

- Vpisthevelocityofpressure(compression);- VsistheVelocityofShearWaves;- GdistheShearElasticdynamicmodule;- EdistheDeformationModule;- μdisthePoisson’scoefficient;


21

TYPE OF EQUIPMENT USED IN CONSTRUCTION and SPECTRA EMISSION OFEQUIPMENTYARD

Theemissionsofvibrationintheconstructionphasearewidelyvariableinrelationtothetypeofequipment/operatingmachineemployed,thecontextofuseandeventheoperators.Technicalreference"Environmentalimpactofroadsandtraffic"-Appl.SciencePublbyLHWatkins- provides a dataset of experimental data about the emission of vibrations by various types ofconstructionmachinesusedinroadconstruction.TheemissionspectraofthemachinesshowninTable9belongstodatasetcontainedinmentionedthetextbook.

Table9accelerationspectrumsofconstructionmachines(dB)(Sources:DOHWAdetaileddesign

documentand"Environmental impactofroadsandtraffic"- Appl. SciencePublbyLHWatkins)

Thespectraofsomemachineryoftheyardmeasuredat5mdistancefromthesourceofvibrationare shown in Figure 5. The Pneumatic Hammer and the Roller Compactor are machineriesprovidingthegreatestimpact,withemittedaccelerationlevelsataround100dBforalargepartofthespectrum.


22

Figure5Accelerationspectraexperimentallymeasured(Sources:"Environmental impactofroadsand

traffic"- Appl. SciencePublbyLHWatkins)

Figure 6 shows the vibration velocity decay (decrease with distance) by types of source - i.e.equipment that will be used during the construction phase. In themodeling, the conservativeapproachwastaken,thatis,thehighestvibrationlevelsofthesourcebetween40-50Hzhavebeentakenandinputted.

Figure6Decaycurvesofthevibrationvelocity(Sources:"Environmental impactofroadsandtraffic"-

Appl. SciencePublbyLHWatkins)


23

As reported in the Report for additional Task 2 of the “Consulting Services for InvestigationofStructural Integrity of, and Impact of Vibration and Noise on Buildings at a Segment of Tbilisi-RustaviRoadProject(Section2,km5,2-6,9)_SoundBarrier (general design)”,traffic forecastfornexttwentyyearsisincontinuousincrement.ThesourceforthisdataisthetablesprovidedbyDohwa. In all relevant documents related to Motorway construction, the future traffic flow isevaluatedupto24yearsfromnow,thatis,foraperiodof20yearsafter theroadconstruction.Thefuturemaximumvehicleflowusedincalculations(forecastedtrafficflowfortheyear2034)is38.909totalvehicles/day,withapercentageof5,2%ofheavyvehicles.Toemulatetheworsttrafficcondition,thisflowhasbeenevenlyspreadonurbanroadlanes.Ithasbeendividedinaperiodof8hours,obtainingtheaveragefluxperhour,4864Vehicles/hourwith5,2%ofheavyvehicles.Asfortheexploitationbeginning,speedhasbeensetto80Km/hwhichisanother conservative assumption (as discussed previously by MDF and ADB lower speed limitmightbesetforthePhonichalasegmentoftheroad).Vibration propagates in the surrounding soil where it is affected by the attenuation, whichdependsonthenatureofthesubsoil,thefrequencyofthesignalandthetravelleddistance.

Figure7trafficvibrationssource-receiverscenario

The characteristics and causes of traffic-induced vibrations are described in guidingmethodological literature which is based on case studies. The bumps of vehicles caused byirregularities in the road surface (e.g., potholes, cracks and uneven manhole covers) inducedynamicloadsonthepavement.Theseburstsofloadsgeneratestresswaves(motions)propagatingin the subsoil when the energy reaches the foundations of a building, and waves still havesufficient energy, themotion is transferred to the foundations generating the vibration of thestructure.Trafficvibrationsaremainlycausedbyheavyvehiclessuchasbusesandtrucksduetotheirweight.Inadditiontothatiftheroadsurfaceroughnessincludesaharmoniccomponentthat,atagivenspeed,leadstoaforcingfrequencycoincidentwithanyofthenaturalfrequenciesofthevehicleand/orthoseofthesoil,additionalsubstantialvibrationsmaybeinduced.According to technical reference sources, traffic produces vibrations with frequenciespredominantlyintherangefrom5to25Hz.Thepredominant frequencies andamplitudeof the vibration dependonmany factors includingthe condition of the road; vehicleweight, speed and suspension system; soil type and subsoil


24

stratification; season of the year (humidity and temperature of the road and subsoil); distancefromtheroad;andtypeofbuilding.The effectsof these factorsareinterdependentanditisstilldifficulttodefinesimplerelationshipsamongthesefactors.Thevibrationaleffectofvehiclespeed,forinstance,alsodependsontheroughnessoftheroadandnotonlyonitskineticenergy.In the present report,inputdata are based on experimental results of several tests conductedin real operating conditions and on the accepted and commonly used scientific datasets andliterature.The Appendix 1 of the reference source Survey of traffic-induced vibrations, A.C.Whiffin, D.R.Leonard. Transport and Road Research Laboratory. Report 418. 1971 summarizes severalexperimental tests,measuring the vibrations generated by test vehicles travelling along normalroad and also over irregularities of the road surface. In the test, vibrationswere recorded byaccelerometersplacedontheroadsurfaceandontheadjacentground,whosecharacteristicswereknown,atvariousdistancesfromtheroadside.Thecomparisonofresultsobtainedatadistanceof3.65mfromtheedgeofroadwithandwithoutartificialsurfaceirregularityshowsthatthepeakvelocitieswiththeirregularitywere anorderofmagnitudegreaterthanthatrecordedwithnormalrunningsurface(Table10).

Table10resultsofmeasurementsoftraffic-inducedvibrationsontrunkRoad(Sources:A.1atAleonburyHil l (Hunts);Surveyoftraffic-inducedvibrations , A.C.Whiffin,D.R.Leonard.Transport

andRoadResearchLaboratory.Report418.1971)

Detailsofroadconstraction

DeflectionUnderDeflectionBean

TestonnormalrunningsurfaceofroadMeasurement3,65fromedgeofroad

TestwithartificialroadsurfaceirregularityinpathofvehicleMeasurementsonroadsurfaceclosetoirregularity

Measurements3.65mfromtheroad

Accel. Ampl. Freq. ParticleVelocity



±g Microns Hz mm/s ±g Microns Hz mm/s ±g Microns Hz mm/sBituminousroadsections–AsphaltsurfaceleanconcretebaseAsphaltsurfacerolledasphaltbaseAsphaltsurfacetar-costedstonebaseAsphaltsurfacestabil isedsoilbaseAsphaltsurfacedrystonebaseBitummacadamsurface,leanconcretebase

300460480510610610

0.0030.0040.0010.0020.0040.004

1.31.00.40.51.51.3

23.729.826.03.4026.522.2

0.190.190.060.100.250.18

0.1320.0530.0770.1100.1170.121

71.135.653.571.173.768.6

21.619.318.919.520.123.2

9.64*4.31*6.33*8.71*9.30*9.99*

0.0200.0120.0090.0140.0150.018

10.78.25.89.99.17.9

21.619.318.919.520.123.2

1.45*0.98*0.69*1.21*1.15*1.15*

Concreteroads250mmslabon76mmhoggin200mmslabon76mmhoggin125mmslabon76mmhoggin200mmslabon225mmleanconcrete

0.0020.0020.0040.003

0.50.51.31.8

30.030.025.818.3

0.10.10.210.2

0.0070.0160.0180.015

5.87.612.48.4

22.222.418.921.1

0.81*1.07*1.47*1.11*


25

In the present study, for a more conservative approach, the tests with artificial road surfaceirregularity are taken in account. As reported in the following paragraphs, these values arecomparedwiththeaccelerationsdatameasuredintheexistingroad.

SPREADOFVIBRATIONSBETWEENSOURCEANDRECEIVER

Whenavibrationisappliedontheground,itspropagationinthesubsoilisaffectedbyattenuationwhichdependsonthenatureofthesubsoil,thefrequencyofthesignalandthetravelleddistance.To theoretically evaluate the impact of vibrational sources, by the application of analyticalformulasitispossibletoobtainacalculationoftheattenuationofthevibrationsasaresultofthepropagationinthesoil.Therearetablesandgraphsallowingtoparametricallyestimatetheattenuationoramplificationcaused by the various structural components of buildings. Combining these information, it ispossible to estimate, with a good approximation (typically +/- 5 dB) the levels of vibrationoccurringattargetareasandthentheireffectsonbuildings.Takingintoaccounttheabove,itcanbeassessed if theexpectedsourceofvibration isnegatively impactingthetargetor if levelsareacceptable.Figure 8 is an example of thedynamics of interaction source-receiver and the events occurringduringthepropagationofthevibrations.

Figure8interactionbetweensourceandreceiverthroughthesoil propagation


26

Propagationofvibrationintheground

Thevibrationlevelatareceiverlocatedatdistance"x"fromthesourceisequaltothelevelatthereferencedistance"x0",minusthecontributionoftheattenuation(Ai)determinedbythetravelinthesoilbetweenx0andx:

𝐿 𝑥 = 𝐿 𝑥0 −∑𝑖𝐴𝑖 (4) Thebasic levelL(x0) isgenerallyobtainedfromexperimentalmeasurementsatdistancesrangingbetween2mand25m.Thecomponentsofattenuationandamplificationofvibrationstobeconsideredinthemodel,asaveragevalues,values,are:

- Geometricattenuation,- Attenuationforinternaldissipationoftheterrain;- Attenuationduetoobstaclesordiscontinuityoftheground.

Thegeometricattenuation(Ag)isdefinedasfollows:

𝐴? = 20𝑙𝑜𝑔 @@0

A (5)

Where “n” is an attenuation coefficient depending on the type of geometric attenuation (seeTable11):

Table11Valuesofattenuationcoefficientduetoradiation(emission)dampingforvarious

combinationofsourcelocationandtype(Source:EnvironmentalImpactofRoadsandTraffic , L.H.Watkins.Routledge.1981)

The Exponent “n” is equal to 0.5 for thewaves of surfaces (predominant in the case of sourceplacedonthesurface),and1forthebulkwaves(predominantinthecaseofdeepsource).Theattenuationduetotheabsorptionoftheground(At)isdefinedasfollows:

𝐴B = 20𝑙𝑜𝑔 𝑒DE(G8G0)

IJ (6)

Where:


27

- ω=2πfisthepulsewave(withf=frequencyinHz);- c=velocityofpropagationinthesoilinm/s;- η=absorptionfactorofthesoil(seeTable12).

Table12Valuesofthedampingparameterasafunctionofthesoil type

Whenawaveencountersaninterfacebetweenlayershavingdifferentvelocityofpropagation,ifthebelowlayerhasalowerspeed,alargepartoftheenergyisbackscattered,withtheresultofdecreasingthetransmittedenergy.Onthecontrary,iftheinterfaceisbetweentwolayerswithanincrease of velocity, the largest part of the energy is transmitted into the faster layer. Thisphenomenon is normally not taken into account, in favor of conservative interpretation of thesimulationdata.

Propagationofvibrationinthestructureofthebuilding

When a vibration wave encounters the foundation of a building, it could be accelerated,attenuated,amplified,couldmodifyitsfrequencyspectraaccordingtothetypeoffoundationandtypeofconstruction,andcouplingbetweenfoundationandsoil,eventhepresenceofwatercanmodifythisbehavior.Differentfoundationsystemscandeterminedifferentlevelsofattenuationof thewaves transmitted into the structure, because of the non-perfect coupling between thestructureandthesubsoilwhichgeneratesdissipationphenomena.Thisphenomenonis influencedbythetypeof foundations(theaterstyle, isolatedonplinths,onreversebeams,piles,etc.). Inthecaseoffoundationsatthestallsthelargeareaofcontactwiththegroundcausesacouplinglossofalmost0dBatlowfrequency,uptotheresonancefrequencyof the foundation. For other types of foundations empirical curves of calculation can be usedallowingtoestimatethevibrationlevelsofthefoundationaccordingtothelevelsofvibrationoftheground.Theattenuationcausedbybuildingcouplinglossstructure-foundationisillustratedinFigure 9 for different categories of buildings. With regard to the category of large reinforcedconcretebuildingswithcontinuousfoundations,thecurveforthelargebuildingsinmasonrywithcontinuousfoundations(seeredcurveinfigure9)isapplied,withaattenuationof2dB.


28

Figure9buildingCouplinglossforvariousbuildingtypes(Source:EnvironmentalImpactofRoads

andTraffic , L.H.Watkins.Routledge.1981)

Spreadingfromthefoundationonthehigherfloorsthevibrationamplitudedecreases,duetothepropagationofvibrationverticallyalongthebuilding,fromleveltolevel;andforthattheselossesmustbetakenintoaccount.Thegeneralassumptionisthatthevibrationdecreasesof2to3dBperflooracrossthespectrum.Figure10showsthetypicalrangeofvariabilityoftheattenuationbetweenfloors.

Figure10Attenuationfromonefloortothenext(Source:EnvironmentalImpactofRoadsand

Traffic , L.H.Watkins.Routledge.1981)

Thephenomenonofresonanceofthestructuralelementsofbuildings, inparticularofthefloorsshould also be examined. It occurs when the excitation frequency coincides with the naturalfrequencyoffreeoscillationofthestructure;fortheeffectsoftheoscillationsthestructureshowsasignificantincreaseofvibrationintheverticaldirectionandminimalvaluesatthebase.


29

The amplification of the floors ranges in an area from 5 dB for frequencies of about 20 Hz tomaximalvaluesof20dBforfrequenciesofabout40Hz.Again,conservatively,theanalysisoftheverticalvibrationwaslimitedtothefirstfloormezzaninesincetheupperfloorsarelessimpactedthanthefirst.Modellingvibrationimpactontheannexesisessentiallythesameasforcorebuildingstructures,yetwith importantdifference.Thecommonlyusedbest internationalpracticeapproach in suchcaseistofactorin“amplificationfactor”called“Storeyamplification”,whichinsimplegeneralizedtermsmeansthatinmodelling,highervibrationamplificationisgiventoassesstheimpactontheannexes. This approach is conservative, it is “worst case scenario” based and thus safe, and ispracticed based on relevant methodological references (e.g. Giuseppe Muscolino : StructureDynamicbehaviour–publisher:THEMCGRAW-HILLCOMPANIES).

4. VIBRATIONCAUSEDBYNEWROADCONSTRUCTIONWORKSANALYSISOFINDIVIDUALBUILDINGS

Using the input of the previously sections the amplitude of vibrations in the receivers (corebuildings and annexes) has been calculated. Table 13 reports, for each building, the result ofmodeling, in particular, the amplitude of vibration generated by the most impacting source(hammerandcompactor)andtheDamageThresholds(thatisthethresholdforminimumdamagenotthreateningstructuralintegrity)accordingtotheconsideredstandardsexplainedinChapter2Vibrations–ImpactLevelsandStandards.


30

Table13Summaryofthesimulatedamplitudeofvibrationsatthereceivers,comparedwith

Standards(DIN4150-3)–constructionworks

Note: thecolumn“category2 long-shortduration(dB)”containsthefigures forLongANDShortvibrationbecauseforcategorybuildings,accordingtoDIN4150-3,thesevaluesaresimilar.

ROLLERCOMPACTOR(dB)

PNEUMATICHAMMER(dB)

mainbuilding annex mainbuilding annex

category2long-shortduration(dB)

category3short

duration(dB)

category3long

duration(dB)

2 9 104,00 101,00 82,36 86,36 79,36 83,36 105 100,5 99

3 22 104,00 101,00 76,93 80,93 73,93 77,93 105 100,5 99

4 19 104,00 101,00 78,38 82,38 75,38 79,38 105 100,5 99

5a 27 104,00 101,00 74,67 78,67 71,67 75,67 105 100,5 99

5b 27 104,00 101,00 74,67 78,67 71,67 75,67 105 100,5 99

5c 27 104,00 101,00 74,67 78,67 71,67 75,67 105 100,5 99

6 30 104,00 101,00 73,40 77,40 70,40 74,40 105 100,5 99

7 52 104,00 101,00 63,00 67,00 60,00 64,00 105 100,5 99

8 57 104,00 101,00 61,24 65,24 58,24 62,24 105 100,5 99

9a 80 104,00 101,00 55,49 59,49 52,49 56,49 105 100,5 99

9b 80 104,00 101,00 55,49 59,49 52,49 56,49 105 100,5 99

10 87 104,00 101,00 53,22 57,22 50,22 54,22 105 100,5 99

STRANDARDTHRESHOLDDIN4150-3/9916.impactonbuildingsMinimum

DistancefromtheRoad(m)

BuildingCode

rollercompactor pneumatichammerSOURCE

RECEIVERLEVELVIBRATION


31

CONCLUSIONSANDRECOMMENDATIONSONVIBRATIONCAUSEDBYNEWROADCONSTRUCTIONWORKS

The analysis of the data reported in the above tables shows that, along the route, the level ofvibrationevaluatedintermsofspeedofvibrations, is lowerthanthethresholdsassignedbytheUNI9916/ISO4866forresidentialbuildings:forthattheexpectedlevelofvibrationscausedbythenewroadconstructionwillnotresultinanydangerofdamagestotheconsideredbuildings.Asfortheannexestothebuildings,eventhoughthemodelingshowednoriskofdamagetotheAnnexes of the resulting from road construction (assuming no other vibration-generatingequipmentormethodthanincludedinthedetaileddesignfortheprojectwillbeusedinpractice)–theAnnexes,mostlybuiltoriginallywithdisregardofessentialengineeringpractices,areinpoorshape.Becauseofthis,itcannotbeexcludedthatotherthanroadconstruction-relatedvibration(e.g. seismicactivity, somefurthermodificationofannexesdoneby the inhabitantsof the flats,otherconstructionactivityorsoilworksinthearea,oracombinationofthese)resultsindamagingorevencollapseofsomeoftheannexes,inwhichcase,theinhabitantsofthebuildingsstillcouldclaimthatthecauseofthedamagehasbeentheconstructionoftheroad.Evenassuming,nosuchclaimswouldbemadeorproved,theAnnexesarenotsafeforthe inhabitantssincethetimeoftheirconstructionandthissafetyproblemshouldbeaddressed.Subsequently, based on the above conclusions, the following measures are stronglyrecommended:

1. Limitingvibration levelsandmonitoringcontractorcompliance:Themodelinghasbeenperformed conservatively (at maximum impact levels for worst case scenarios) and theconclusionsandrecommendationsareprovidedconservativelyaswelldespitesomesafetymargin allowedby this conservative approach. Themodellinghas been conductedwhileinputting the vibration data for the equipment, construction method and road andconstructionyardalignmentclearlyspecifiedinthedetailedengineeringdesigndocumentsprepared by Dohwa. The above conclusions are valid only in case no other method orequipmentgeneratingvibrationthanspecifiedbyDohwaisapplied.Subsequently,itismandatoryto:

a. Instruct the Contractor to follow strictly, under a legal liability, the constructionmethod and equipment list, and respect theboundaries of the construction yardduringconstructionworks.Thecontractorshouldfurtherseektheapprovaloftheclient (MDF)ofanyneedofmodifyingconstructionmethod,usingequipmentnotspecified in the detailed design documents or exceed the boundaries of theconstructionyard.


32

b. According to good international practices in the similar cases, perform, ongoingpermanent supervision of the construction works to establish compliance of thecontractor with conditions specified in point “a.” above. The supervisionmechanismshouldincludethetoolsofimmediateidentificationoftheproblemandtheauthorityofthesupervisoragenttohaltworks,recordthenon-complianceandissueamandatorycorrectiveactioninstructiontothecontractor.

2. Reinforcing the Annexes: Even though modelling showed no risk of damage to the

annexes, due to the condition of Annexes determined by their faulty design, practicaldifficultiesrelatedtoestablishingthattheroad-relatedactivitieshavenotbeenthecauseofadamage,andmostimportantly,lackofsafetyoftheAnnexesatanytimesincethedayoftheirconstruction–itisrecommendedtoreinforcetheAnnexes.Theengineeringdesignof reinforcement works reported under the assignment of NEP Srl. can be used inimplementing reinforcements. The suggested method is effective, least expensive andpossibletoimplementintheshortestperiodoftime.

3. Technical monitoring campaign: Furthermore, given the legal sensitivity and thebackground of the case, again, based on best international practices, it is stronglyrecommendedtoconductapropertechnicalmonitoringcampaignfortheclient(MDF)topossessalegallyundisputablerecordofvibrationlevels/impactsvisavisanyclaimsbytheresidents or to establish legal responsibility of the contractor in case of need. Draftmonitoringplan reportedunder theassignmentofNEPSrl. canbeused inplanningandimplementingsuchcampaign.


33

5. VIBRATIONCOMINGFROMTHEOPERATIONOFTHENEWROAD

Asreportedabove,themaximumvaluesofpeakvelocity(mm/s)measured3.65mfromtheedgeoftheroad(Tab.10)is1.45mm/s.One of the requirements of the Additional Assignment 2 was to, whenever methodologicallypossible, input field data rather than othermethodologically credible assumptions inmodelingandanalysisinordertovalidatetheanalysisandconclusionsofthepreviousimpactinvestigation.To meet this requirement, first, vibration reference values provided in guiding methodologicalsourceswereretrieved(source:Trafficvibrationsinbuildings.OsamaHunaidi.NationalResearchCouncilofCanada.ISSN1206-1220ConstructionTechnologyUpdateNo.39.June2000).Secondly,and most importantly, several measurements of the amplitude of vibrations induced by theexistingroad(Task1oftheScopeofthisassignment)havebeenperformed,asbelowreported.Comparison of the two showed that the field measurements (referred in the tables below asDynamic Vibration) were almost two times higher than figures in methodological referencesources.Consequently, followingoverall conservativeapproach, thehigher figuresofvelocityofvibrationwereinputtedinmodelingroadoperationimpacts.


34

ACQUISITIONOFVIBRATIONMEASUREMENTS

Dataareacquiredaccordingtothefollowingstandards:- SO/FDIS4866–“Mechanicalvibrationandshock,Vibrationoffixedstructures,Guidelines

forthemeasurementofvibrationsandevaluationoftheireffectsonstructures”.SensorswereinstallednearthecrosssectionoftheexistingUrbanRoadandincorrespondenceofthefoundationofBuilding#10(Fig.11).

Figure11Layoutofaccelerometersplacedformeasurementsoftraffic-inducedvibrations

Sensorn.1(ACC#1)isplacedinproximityofBuilding#10,andSensorn.2(ACC#2)isplacedneartheexistingRoad,3.5mfromtheroadedgeand27mfarfromACC#1.

ACC#1

ACC#2


35

Figure12ACC#2–existingRoad


36

Equipment

Awiredsensornetworkcomposedofthefollowingelementswasused:- piezoelectric sensors (Integrated Electronic Piezoelectric - IEPE) KS48C-MMF with voltage

sensitivityof1V/gandmeasurementrangeof±6g.(calibrationcertificatesdatedabout40daysbeforethetest)

Figure13piezoelectricsensorsKS48C-MMF


37

- digitalrecorder(DaTa500)composedbya24-bitDigitalSignalProcessor(DSP),ananaloganti-aliasingfilterandahigh-frequencyacquisitionrange(0.2Hzto200kHz).

Figure14Digitalrecorder(DaTa500)


38

- RG58coaxialcableslinkfromccelerometerstorecorder;- M28andM32signalconditionerswithfrequencyrangeof0.1to100kHzandadjustableegain.

Figure15M28andM32signalconditioners


39

AnalysisofacquiredData

Data are acquired with at a sample rate of 1.000Hz. Time histories show the relevant peaksacquired caused by traffic-induced vibrations. Accelerations (mm/s2) are integrated in order toobtainvelocities(mm/s).

Figure16Timehistoriesoftraffic-inducedvibrations


40

Figure17Timehistoriesoftraffic-inducedvibrations


41

Asaresultthemainvelocityvalueisrecordedatminute8.25,withanamplitudeofvelocityequalto0.884mm/sincorrespondenceoftheroad(ACC#2).For the calculation of traffic-induced vibrations, conservatively, the maxim values frommethodologicalreferences-equalto1.45mm/s–havebeentaken.Usingthreeformulaeabove,thevalueisconvertedinasingleratingscaleindB,witchcorrespondanaccelerationlevel(dB)equalto94dBasreportedbelow:

𝐿" = 𝐿( − 29 = 20𝑙𝑜𝑔 7.L67289

− 29 =94dBThissourcevaluehasbeenusedforthecalculationsinordertoobtainthesimulatedaccelerationvaluesineachreceivers(Buildings).


42

ANALYSISOFINDIVIDUALBUILDINGS

Usingtheinputdescribedabove,theamplitudeofvibrationsinthereceivers(building)hasbeencalculated.Table14containsthelevelsoftheamplitudeofvibrationcausedbytrafficduringroadoperationandthethresholdsimposedbythestandards-foreachbuildinganditsannex.


Standards(DIN4150-3)- traffic

Note: thecolumn“category2 long-shortduration(dB)”containsthefigures forLongANDShortvibrationbecauseforcategorybuildings,accordingtoDIN4150-3,thesevaluesaresimilar.

mainbuild annex

TRAFFIC(dB) Refdistance(X0)m TRAFFIC TRAFFIC


category3shortduration

(dB)

category3longduration

(dB)

2 9 94,00 3,65 70,62 74,62 105 100,5 99

3 22 94,00 3,65 65,19 69,19 105 100,5 99

4 19 94,00 3,65 66,65 70,65 105 100,5 99

5a 27 94,00 3,65 62,94 66,94 105 100,5 99

5b 27 94,00 3,65 62,94 66,94 105 100,5 99

5c 27 94,00 3,65 62,94 66,94 105 100,5 99

6 30 94,00 3,65 61,66 65,66 105 100,5 99

7 52 94,00 3,65 51,27 55,27 105 100,5 99

8 57 94,00 3,65 49,51 53,51 105 100,5 99

9a 80 94,00 3,65 43,76 47,76 105 100,5 99

9b 80 94,00 3,65 43,76 47,76 105 100,5 99

10 87 94,00 3,65 41,48 45,48 105 100,5 99

STRANDARDTHRESHOLDDIN4150-3/9916.impactonbuildings


BuildingCode


SOURCE


43

CONCLUSIONSANDRECOMMENDATIONSONVIBRATIONCAUSEDBYNEWROADOPERATION

Asexpected,analysisofthedatareportedintheabovetablesshowthattheimpactofvibrationcausedby trafficon thenew road (evaluated in termsof speedof vibrations) is lower than thethresholds assigned by the UNI 9916 / ISO 4866 for residential buildings. Results of modellingimpacts ofvibration causedby traffic loadon thenew road shownodirect effect of damageeithertocorebuildingsortotheannexes.However, the factor of inherent structural weakness of the Annexes, and the future post-commissioningworksofmaintenanceofthenewroad(asthemeasuresthatreducethevibrationandatthesametimearethesourceofvibration)shouldbefactoredinintodrawingconclusionsandrecommendations.Specifically,thefollowingmeasuresarestronglyrecommended:

1. ReinforcingtheAnnexes(thesameasvoluntaryadditions):Thesamerecommendationasmade for the vibration impact caused by construction works – applies. Even thoughmodelling showed no risk of damage to the annexes, due to the condition of Annexesdetermined by their faulty design, practical difficulties related to establishing that theroad-relatedactivitieshavenotbeenthecauseofadamage,andmostimportantly,lackofsafetyoftheAnnexesatanytimesincethedayoftheirconstruction–itisrecommendedtoreinforcetheAnnexes.Theengineeringdesignofreinforcementworksreportedunderthe assignment of NEP Srl. can be used in implementing reinforcements. The suggestedmethod iseffective, leastexpensiveandpossible to implement in the shortestperiodoftime.

2. Preventingincreasedvibrationresultingfromtheroadsurfacedeterioration:Withtime,due to wear and other environmental factors, road surface develops defects, most ofwhich(e.g.bumps)arethecauseofvibration.Theroadsurfacequalityshouldberegularlymonitored to prevent and fix in timely and sustainablemanner the defects that in turncause increase in vibration caused by traffic load of the new road. Adequate resourcesshouldbeallocatedformaintenanceofthePhonochalasegmentofthenewroadandallmaintenanceworksshouldbeconductedpreventivelyorswiftlyasthedamageoccurs.

3. Technical Monitoring Campaign: The campaign can be conducted periodically if not

permanentlyandatleastforthefirst12-18monthsaftercommissioningoftheroadwhichwill allow todetermine thepattern anddecideonwhether further technicalmonitoringmeans are required. In addition, in case of discontinued technical monitoring, relevant


44

sensors can be set up and data recorded during the maintenance works to establishcomplianceofthemaintenancecontractors.


45

6. VIBRATIONGENERATEDTHROUGHCONSTRUCTIONOFTHENOISEMITIGATIONSTRUCTURES

NOISEMITIGATIONMEASURES

This section reports the main features of the draft report “Noise Modelling of Tbilisi-RustaviHighway (section 2)”, dated April 29, 2017 and shared with DRC and 4EMME with therecommendation to be considered in the analysis as reflected in the scope of work for thisassignment. This report evaluates the noise potentially generated from the proposed newsegmentoftheSection2,particularlyitswesternportionwherethebuildingsarecloserandthenoiselevelscouldbeamatterofconcern.Thereportproposesthefourmitigationoptionsbelowlisted:

- W (Noise wall with maximum height of 8 m). In this two noise-absorbing barriers arerecommended; a first one 6-m high, 988m and a second one 8m high and 640m long(Fig.18).Despitetheirdimensionsthesebarrierswillnotachievecompleteabatementandwillthereforerequiretherelocationof5buildings.

Figure18LayoutandCompliancestatusforNoiseWall (Maximumheightof8m)

- W’ (Noise absorbing barrierwithmaximumheight of 9m). In this solution three noisewallsarerecommended—one6mhigh,1,120mlong,asecondone8mhighand240mlongandathirdone9mhighand268mlong(Fig.19).Thesewallswillnotachievereducethenoise to the threshold levels abatement and will therefore require the relocation of 4buildings.


46


- W+IRS (Noisewallwith improvedroadsurface). Inthissolutionanoisewalland improvedroad surface are recommended. The noise wall will be 5m high and 1,628m long (Fig.20).Despite its shorter length, about 26% less than previous options (noisewall only); itwill benecessary to replace the standard asphalt with porous asphalt to reduce the noise at thesourceforatotallengthof1.6km.



47

- W+T (Noisewallwith tunnel). This lastoption requires the constructionofone tunnelandanoisewallasshowninthebelowFig.21.Thetunnelwillstretchforalengthof560mandwill coverall lanes. Itsheightwillbe5m,which is thesameof the tunnelunder therailwayline.Twofulfillthegoalofnoisereductiontwonoisewallsarealsonecessary:one5mhigh,880mlongandasecond8mhighand188mlong.


ExamplesoftypicalnoisewallandnoisetunnelareshowninFig.22andFig.23.

Figure22ATypicalTransparentNoiseWall


48

Figure23ATypicalTunnelNoiseBarrier

Constructionof noisemitigation structures suggested, regardless alternatives and their possiblecombinations,requireanchoringandmasonrystructuretoholdthecolumnsofthebarriers.Thelengthandnumberofthecolumns willdependingonthetypeandlayoutofthesestructures.Theminimum distance between the noise barrier and the buildings as recommend in the noisemodellingisinTable15.

Table15distancesfromtheRoadandfoundationsofnoisemitigations(piles)tothebuildings

Internationalbestpracticesfortheconstructionofnoisemitigationstructuressuggeststherearetwokeymethodsandare:

2 5Km+300 9 6

3 5Km+370 22 19

4 5Km+470 19 16

5a 5Km+660 27 24

5b 5Km+660 27 24

5c 5Km+660 27 24

6 5Km+780 30 27

7 5Km+370 52 49

8 5Km+440 57 54

9a 5Km+520 80 77

9b 5Km+520 80 77

10 5Km+600 87 84

BuildingCode



MinimunDistancefromthepiles(noisemitigations)(m)


49

a) PrecastSoundWalls isselectedforthesoundwallsduetocostorotherconsiderations,DrillPiling is used to support the Precast Sound Walls – Field Installation Best Practices Manual,National Precast Concrete Association, USA (NCPA) - Annex 4 attached to this Report1. The bestpracticesdeterminedinthismanualareinturnbasedonseveralrelevantU.S.constructionstandardsthatarewidelyappliedinternationallyaswell.Thesestandardsarerecommendedtobereferredtobythedesignerengineerofthenoisemitigationstructuresandinclude:• AASHTOR20–StandardPracticeProceduresforMeasuringHighwayNoise• FHWAHighwayNoiseBarrierDesignHandbook.• NPCASoundWallBestPracticesManual• NPCASoundWallTechnicalBrochure

ForBackfillPlacementandCompactionworks,theManualrecommends“Compactionofthebackllshallbecompletedusinglightweightcompactionequipmentsothatthewall’sstabilityisnotdisruptedorcompromisedbyvibrationfromoperationofheavyequipment.

TheotherreferencesourceforthenoisemitigationstructuresisFHWAHIGHWAYNOISEBARRIERDESIGNHANDBOOK,U.S.DepartmentofTransportation,FederalHighwayAdministration,FHWA-EP-00-005DOT-VNTSC-FHWA-00-01,PB2000-105872.TheHandbookoutlinesindetailtheTypesofNoiseBarrierandtheirAcousticConsiderations;NoiseBarrierMaterialsandSurfaceTreatments;aswellasStructural,Drainage,Installation,Maintenance,Cost,Aesthetic,EffectivenessAssessmentconsiderationsandrecommendsapproachesforthenoisebarrierdesignprocess.TheHandbookconsiders,ConcreteSlubFoundations(seeFigure24below)astheproperandcommonsolution2.

Figure24:ExamplesofConcreteSlubFoundationswithContinuousandSpreadFooting.

1SeePage5oftheNCPAManual.2SeeFHWAHandbook,pages4and13.


50

ConstructionofConcreteSlubFoundationsrequiresshallowexcavationworksthatdonotrequiretheuseofheavyexcavationmachinerycapableofproducingvibrationlevelsworthofconsidering.

Vibrationimpactduetopiling:Thedataregardingvibrationemissionsoftheequipmentnormallyusedinnoisemitigationmeasures’constructionisavailableinmethodologicalreferencesources–providedinTable16below.Constructionvibrationisgenerallyassessedintermsofpeakparticlevelocity (PPV). Table 16 gives typical vibration levels for representative types of equipment; asvisible, therangeofvariation isverywide,but these tablesprovidea reasonableestimation forwiderangeofsoilconditions.However,regardlessthesoilcharacterizationparameters,itisclearthatitisonlythepiledriveriscapableofproducingthevibrationlevelsatthesourceoforiginationthatishigherthanthedamagethresholdof105dBatthereceivingpoint.AsitisshowninTable16, other equipment to be used cannot produce vibration impact equal or above damagethreshold.

Table16vibrationsourcelevelsforconstructionequipment–measureddata(Source:Ground

vibrationsfromimpactpiledrivingduringroadconstruction,D.J. Martin,supplementaryreport544,UnitedKingdomDepartmentoftheEnvironment,DepartmentofTransport,1980)

The data of vibration emissions of construction machinery are not available in machinerydatasheets,forthatitisacommonandacceptedpracticetousethereferencevaluesreportedinliterature.Asexpected,piledriverimpactproducesthehighestvaluesofinducedvibrations.Thehigher value of amplitude vibration (velocity) of the pile driver is equal to1.518 in/sec, whichcorrespondsto38.35mm/s.The results of modeling of equipment vibration impacts at the receiver level of vibrationsgeneratedbypiledriverforeachbuildingareprovidedinTable17below.


51

ANALYSISOFINDIVIDUALBUILDINGS

Table17isgivenbelowbelowfordemonstrationpurposeonly.TheTablecontainsthedataofmodelingperformedforcomparisonofvibrationimpactproducedbydrivepiling(neverconsideredorrequiredforPhonichalaareaandnotrecommendedintheConclusionsandRecommendationssectionbelow)withthevibrationimpactproducedbyasafepilingsolution-drillpiling.


Standards(DIN4150-3)–piledriver

Piledriversgeneratethemaximumvibrationlevels,especiallyduringthestart-upandshut-downphasesoftheoperationbecauseofthevariousresonancesthatoccurduringvibratorypiledriving.Maximumvibrationoccurswhenthevibratorypiledriverisoperatingattheresonancefrequencyof thesoil-pile-driver system.The frequencydependsonpropertiesof thesoil layerswhere thepileisdriven.AsreportedinTable17,formanybuildings,thesimulatedamplitudeofvibrationsinducedinanunlikelycaseofusingdrivepilesexceedsthethresholdsbystandards.inparticular,hadpiledrivingbeenused:

- Buildings2,3,4,5,6wouldhavebeenparticularlyvulnerabletovibrationsand,forthosebuildings,structuraldamageisexpected.

- Buildings7,8,9,10aresufficientlyfarforthesourceofvibration(over49m),sostructuraldamageevenusingpiledriverswouldn’thavebeenexpected.


52

Asindicatedabove,neitherthenatureofthesubsoilinPhonichalaarearequireresortingtopiledriving,nordrivepilinghasbeenconsideredorrecommendedinanydocumentordiscussionregardingbuildingnoisemitigationstructuresinPhonichalaarea.TheFHWAHIGHWAYNOISEBARRIERDESIGNHANDBOOK3makesareferencetoPileDriving(andrespectively-drivepiles)asariskysolution-theriskthatwasconfirmedbytheimpactmodellingsimulation(Table17).

b) Noisemitigationstructureswithlightweightpre-manufacturedcomponentsaremadeofcomposite/polymermaterials.Therearemultipleoptionstochoosefrominthistypeofstructuresdependingofthetypeofmaterialofthestructuresections,preciseconfigurationofthestructurecomponent set, installation techniques, cost, visual transparency, specific noise absorptioncapacityetc. Incase light-weightcompositematerialnoisemitigationstructuresare selected, interms of vibration, the execution design engineer should carefully examine the type offoundationsrequired.Anexampleforalight-weightmitigationstructure–thestructures“AILSoundWalls”isattachedbelow (Please, see ANNEX 6: AIL SOUNDWALLS, Engineering Noise Mitigation Solutions). Thereference source is a company brochure that shows the examples of possible solutions,installationtechniquesincludingfooting(fundaments)anddiscussestheadvantagesofthisoptionetc. Please, see Figure 25 below for example of pile mounting applied for light-weight noisebarriers.Importantdisclaimer:thebrochureAILSOUNDWALLScontainstheinformationaboutparticularproductprovidedbyaparticularcompany.ThebrochureisreferredandattachedtothisReportsolelyforillustrativepurposeasoneofmultipleexamplesandbynomeanstheConsultantTeamendorsesorrecommendsthisparticularproductorcompanyforanyfurtheractivityrelatedtothe

futureconstructionofnoisemitigationstructuresinPhonichala.

3PrecastSoundWalls–FieldInstallationBestPracticesManual,NationalPrecastConcreteAssociation,USA(NCPA).FHWAHIGHWAYNOISEBARRIERDESIGNHANDBOOK,U.S.DepartmentofTransportation,FederalHighwayAdministration,FHWA-EP-00-005DOT-VNTSC-FHWA-00-01,PB2000-105872.


53

Figure25:Examplesofthefooting(fundament)ofal ight-weightnoisemitigationstructure

Thefooting(showninFig25)requiresshallowpilingasopposedtobuildingconcreteslubfoundationdiscussedabove.DrillPiling(oftenalsoreferredasBorePiling)ontheotherhandisconsideredininternationalbestpracticesasasafesolutionintermsofvibrationemissions,nottomentionotheradvantages.

Usingdrilledpilesprovidesseveraladvantages:- Nocasinginstallationrequired- Littleworkingspacerequired- Marginaldistancestonearbybuildingspossible- Lowvibrationandnoiselevel- Noimpactongroundwater- Nounnecessarypilelenghtsrequired- Noundergroundcavityformation

Boredpilescastinsituaremadeataverylowvibrationlevelsandonpractice,inthesimilarcases,itisassumedthatthelevelofvibrationproducedbydrillpilingisnegligible.Itisrecommendedtousetwodifferentsizesofshaftdiametersrangingfrom40cmto60cm.Highervaluesofdiameters


54

will require more noisy and heavy equipment that conservatively could generate considerablevibrationsonthebuildings.Internationalbestpracticereferencesourcesprovidenoreferencetovibrationgeneratedbydrillpilingandthemanufacturersofdrillingmachinesforpiles(whoforobviousreasonsoflegalliabilityareobligedtobeguidedbyasetofregulationsincludingthoserelatedtovibrationimpacts)declarezerovibrationemissionsforthistypeofdrilling.Yet,conservatively,themodellingofdrillpileimpacttothePhonichalabuildingswasperformedwhilefactoringindrillpilingvibrationlevelstakenasequaltothoseproducedbyrollercompactor.TheresultsofmodelingareprovidedinTable18below.

Table18Summaryofthesimulatedamplitudeofvibrationsatthereceivers,comparedwithStandards(DIN4150-3)–piledril l ing

Note: thecolumn“category2 long-shortduration(dB)”containsthefigures forLongANDShortvibrationbecauseforcategorybuildings,accordingtoDIN4150-3,thesevaluesaresimilar.TheresultsofconservativemodelinggiveninTable18showthattheimpactofpiledrillingatthereceivingpointsislowerthandamagethreshold.Themaximumpilelengththatcanbeobtainedis16mand8mrespectively(Table19).

mainbuild annex

PILE(dB)Refdistance

(X0)mPILES PILES


category3short

duration(dB)

category3long

duration(dB)

2 9 6 104,00 7,62 95,00 99,00 105 100,5 99

3 22 19 104,00 7,62 90,93 94,93 105 100,5 99

4 19 16 104,00 7,62 92,49 96,49 105 100,5 99

5a 27 24 104,00 7,62 88,55 92,55 105 100,5 99

5b 27 24 104,00 7,62 88,55 92,55 105 100,5 99

5c 27 24 104,00 7,62 88,55 92,55 105 100,5 99

6 30 27 104,00 7,62 87,22 91,22 105 100,5 99

7 52 49 104,00 7,62 78,63 82,63 105 100,5 99

8 57 54 104,00 7,62 76,84 80,84 105 100,5 99

9a 80 77 104,00 7,62 69,02 73,02 105 100,5 99

9b 80 77 104,00 7,62 69,02 73,02 105 100,5 99

10 87 84 104,00 7,62 66,73 70,73 105 100,5 99



BuildingCode



SOURCE


55

Table19–dril ledpiles–lengthanddiametersusable

ThemaximumvaluesofdiametersthatcanbeusedduringtheconstructionofthenoisewallandtunnelaregiveninTable20.

Table20–typeanddiametersofpilesrecommendedduringtheconstructionofnoisemitigation

structures

AlthoughformallythecalculationsshowthatforBuildings7,8,9,10,thediameterofdrilledpilescanbeincrementedupto80cm,becauseofthehighdistancebetweensource-receivers(52m–87m),stillthelimitationof60cmdiametershallapplybecauseBuildings7,8,9,10arelocatedbehindtheothermostimpactedbuildings.

2 9 6 Drilled 60

3 22 19 Drilled 60

4 19 16 Drilled 60

5a 27 24 Drilled 60

5b 27 24 Drilled 60

5c 27 24 Drilled 60

6 30 27 Drilled 60

7 52 49 Drilled 80

8 57 54 Drilled 80

9a 80 77 Drilled 80

9b 80 77 Drilled 80

10 87 84 Drilled 80

BuildingCode



Maximumdiameterpile

(Øcm)TypeofPile


56

CONCLUSIONSANDRECOMMENDATIONSONVIBRATIONGENERATED THROUGHCONSTRUCTIONOFTHENOISEMITIGATIONSTRUCTURES

To summarize the analysis provided in this section, the followingmandatory recommendationsshouldbemade:

1. Piledrilling,asopposedtopiledrivingshouldbeusedshalltheexecutiondesignengineerchooseastructureinvolvingpilefootingfornoisemitigationstructures(thesecouldbelightweightpre-manufacturedcomponents,asrecoemmendedbytheNoiseModelingstudy).Insuchcase,thediameterofpilesshallbelimitedto60cmdiameterforthefulllengthofthemitigationstructurealignmentinfrontofbuildingsinfocus.

2. ReinforcingtheAnnexes(thesameasvoluntaryadditions):Thesamerecommendationas

madeforthevibrationimpactcausedbyconstructionworksandroadoperation–applies.Eventhoughmodellingshowednoriskofdamagetotheannexes,duetotheconditionofAnnexesdeterminedbytheirfaultydesign,practicaldifficultiesrelatedtoestablishingthattheroad-relatedactivitieshavenotbeenthecauseofadamage,andmostimportantly,lackofsafetyoftheAnnexesatanytimesincethedayoftheirconstruction–itisrecommendedtoreinforcetheAnnexes.TheengineeringdesignofreinforcementworksreportedundertheassignmentofNEPSrl.canbeusedinimplementingreinforcements.Thesuggestedmethodiseffective,leastexpensiveandpossibletoimplementintheshortestperiodoftime.

Furthermore,similarlytotheroadconstructionandmaintenanceworks:3. Monitoringforcompliance:Themitigationmeasuresconstructionworksshouldbecarefully

monitoredforcompliancewiththesetparameters.Thesupervisionmechanismshouldincludethetoolsofimmediateidentificationoftheproblemandtheauthorityofthesupervisoragenttohaltworks,recordthenon-complianceandissueamandatorycorrectiveactioninstructiontothecontractor.

Standardstobeconsideredbytheexecutiondesignengineershallbeguidedbyreferencesourcesrelevanttotheselectedtypeofstructureandfundament-suchas:PrecastSoundWalls–FieldInstallationBestPracticesManual,NationalPrecastConcreteAssociation,USA(NCPA),AASHTO,FHWA,NPCAreferencesquotedthereby;andFHWAHIGHWAYNOISEBARRIERDESIGNHANDBOOK,U.S.DepartmentofTransportation,FederalHighwayAdministrationaswellasotherrelevantguidelinereferencesquotedintheHandbookorsimilarinternationallyrecognizedstandards.


57

7. SUMMARYTABLEOFALLFINDINGSForconvenience,asummaryoftheresultsobtainedbythenumericalsimulationsarereportedinTable21.

Table21summaryofvibrationsinducedbyconstructionroad,operationconditionsandnoise

mitigationstructureswithdri l ledpilefoundation

Note: thecolumn“category2 long-shortduration(dB)”containsthefigures forLongANDShortvibrationbecauseforcategorybuildings,accordingtoDIN4150-3,thesevaluesaresimilar.The results obtained by the numerical simulations are sufficiently lower than the thresholdsassigned by the Standards for residential buildings (assumingmandatory recommendations forpilingworksduringconstructionofnoisemitigationstructuresarefollowed),consideringthepoorstateofconservationofallbuildings, inparticularoftheannexes,avibrationmonitoringduringoperation of theUrbanRoad and noisemitigation structures is recommendedas indicated inrecommendationssectionabove.The aim of vibration monitoring campaign is checking the vibrational levels considering anycriticalconditionsorchangesinthesituationbeforeworkandtheoperatingconditions,indefinedpoints.The vibrationmonitoring ensures the adequate knowledge and control of the phenomenon ofvibration, in relation topotentialeffects inducedbyconstructionworksandroadoperationandmaintenance.

traffic traffic

mainbuilding

annexmain

buildingannex

mainbuilding

mainbuildingmain

buildingmain

building


category3short

duration(dB)

category3long

duration(dB)

2 9 82,36 86,36 79,36 83,36 70,62 74,62 95,00 99,00 60 105 100,5 99

3 22 76,93 80,93 73,93 77,93 65,19 69,19 90,93 94,93 60 105 100,5 99

4 19 78,38 82,38 75,38 79,38 66,65 70,65 92,49 96,49 60 105 100,5 99

5a 27 74,67 78,67 71,67 75,67 62,94 66,94 88,55 92,55 60 105 100,5 99

5b 27 74,67 78,67 71,67 75,67 62,94 66,94 88,55 92,55 60 105 100,5 99

5c 27 74,67 78,67 71,67 75,67 62,94 66,94 88,55 92,55 60 105 100,5 99

6 30 73,40 77,40 70,40 74,40 61,66 65,66 87,22 91,22 60 105 100,5 99

7 52 63,00 67,00 60,00 64,00 51,27 55,27 78,63 82,63 80 105 100,5 99

8 57 61,24 65,24 58,24 62,24 49,51 53,51 76,84 80,84 80 105 100,5 99

9a 80 55,49 59,49 52,49 56,49 43,76 47,76 69,02 73,02 80 105 100,5 99

9b 80 55,49 59,49 52,49 56,49 43,76 47,76 69,02 73,02 80 105 100,5 99

10 87 53,22 57,22 50,22 54,22 41,48 45,48 66,73 70,73 80 105 100,5 99


VIBRATIONSOPERATIONCONDITIONS(dB)

VIBRATIONSNOISEMITIGATION(dB)

Maximumdiameter

DRILLEDpile(Øcm)

BuildingCode


rollercompactor pneumatichammer

VIBRATIONSCONSTRUCTIONWORKS(dB)

piles


58

REFERENCESSurvey of traffic-induced vibrations, A.C. Whiffin, D.R. Leonard. Transport and Road ResearchLaboratory.Report418.1971EnvironmentalImpactofRoadsandTraffic,L.H.Watkins.Routledge.1981Trafficvibrations inbuildings.OsamaHunaidi.NationalResearchCouncilofCanada. ISSN1206-1220ConstructionTechnologyUpdateNo.39.June2000ISO/FDIS4866:2009 INTERNATIONALSTANDARD.Mechanicalvibrationandshock—Vibrationoffixedstructures—Guidelinesforthemeasurementofvibrationsandevaluationoftheireffectsonstructures.UNI9614:1990“Misuradellevibrazioninegliedificiecriteridivalutazionedeldisturbo”.UNI9916:2004“Criteridimisuraevalutazionedeglieffettidellevibrazionisugliedifici”DIN4150-3“Effectsofvibrationonstructures”.Groundvibrationsfromimpactpiledrivingduringroadconstruction,D.J.Martin,supplementaryreport544,UnitedKingdomDepartmentoftheEnvironment,DepartmentofTransport,1980Vibration during construction operations, J.F.Wiss, Journal of Construction Division, AmericanSocietyofCivilEngineersn.100,1974.Survey of traffic-induced vibrations, A.C. Whiffin, D.R. Leonard. Transport and Road ResearchLaboratory.Report418.1971.TBILISI-RUSTAVIROAD,DOHWAdetaileddesigndocuments.

PrecastSoundWalls–FieldInstallationBestPracticesManual,NationalPrecastConcreteAssociation,USA(NCPA).FHWAHIGHWAYNOISEBARRIERDESIGNHANDBOOK,U.S.DepartmentofTransportation,FederalHighwayAdministration,FHWA-EP-00-005DOT-VNTSC-FHWA-00-01,PB2000-105872.

AILSOUNDWALLS,EngineeringNoiseMitigationSolutions.


59

8. ANNEXESANNEX1:Inputdata(enteredinthemodel)

ANNEX 2: Raw data of measurements of vibration from present day road –separateattachment

ANNEX3:Outputsofmodeling(datatables)

ANNEX 4: Field Installation Best Practices Manual, National Precast ConcreteAssociation,USA(NCPA).

ANNEX5:FHWAHIGHWAYNOISEBARRIERDESIGNHANDBOOK,U.S.DepartmentofTransportation,FederalHighwayAdministration,FHWA-EP-00-005DOT-VNTSC-FHWA-00-01,PB2000-105872.

ANNEX6:AILSOUNDWALLS,EngineeringNoiseMitigationSolutions(anexampleofinternationalbestpractices)

SUTIP2/C/QCBS/08-2015 Development of a bridge and tunnel...

Documents

Transcript of SUTIP2/C/QCBS/08-2015 Development of a bridge and tunnel...