Si t ee xper i ment sf orbl as t i ngvi br at i onr educ t i on us i ngc ont r ol l i ngi ni t i at i on

Article

‖‖川‖‖ll=川II

Si t ee xper i ment sf orbl as t i ngvi br at i onr educ t i on us i ngc ont r ol l i ngi ni t i at i on

YujiOgata*,Woo･JinJung★.KazuoAoki*,KunihisaKatsuyama★★,Ktmi yoshiOhtake***,

NagaoMiyamura'*',AtSumi Miyake' 'l",andTerushigeOgaWa*''*

TeStblastingwasCarriedoutforthe8pplicabilityofvibrationreductionmethodbycontrolling theinitiationtimeinthequarry.Theblastingdesignwastakenlikethattheblastholeinterval i82m AB10holes48tageS,lineofleaStresistancei82m,blastholediameteri865mm.The blastinginitiationtimeortheexperimentsSetdifferencetimeevery10holes1stage.The initiationdelaytimewasCAIculatedbythefrequencyanalySi80rthetestblastingvibration.

SimultaneouBly,italsoobtainedadelaytimeaslargestnegativecorrelationaccordingto autocorrelationfunctionorvibrationwaveform,andthe8etLingmethodoroptimum delay init,iationtimewasdiSCu8Sed.

Themaximumofvibrationlevelisabout22.5HzaStheresultorthefrequencyanalysis0r teStblasting.Sotheoptimum timedifferencei822.2mseachinitiationtime.Thisvalueshows anegativevalueevenintheanalys18accordingtotheAutOCOrreJAtionfunction.ItwasShown thatthebl朗tingvibrationcoutdbereducedbytheinterferenceofthebh8tingvibrationwith optimt1mtimebythefrequencyAnalysisusingpreciseinitiationmachineandelectricdetonatOr orlthefieldexperimentinthequarry.

1. lntrodu￠tion

BlaSting iswidely used in miningand fundamentalconstructionbecauseOfitsspeedand economytodestroytherock8Andbuilding.

Bl88tinghABtheadvantagesofreducedexcavation co8t8andShortenedconstructiontimewhen comparedtotheuseofheavymachineryfor excavationandcuttingsuchasthatwithatunnel boringmachine.Howeverthereare80meproblems withblasting,lnCludingthenoi白e,Vibrationand nyrock.ItbecomesaSeriousproblem thatthe blastingvibrationi畠reducedinminingand fundamentalconstruction.Asgeneralbla8ting

Received:May17,2002 Accepted:September2,2002

'NAtionallmStituteorAdvanccdIndustrial ScicnceandTechnolow,16･10nogaWaT岳ukuha lbaraki30518569,JAPAN

''EhimeUniversity,3･5･7TnrumiMat811ytlm凡 Ehime790･8566,JAPAN

'''KacohCo.Ltd.,4･INishirtlkudaL･yOKtmda ChiyodakuTbky0101･0037.JAPAN

…●YokolmmaNationalUniversity,79･51もkiwEIdai HodogayakuYokohamaKanagaW824018501, JAPAN

vibrationmethodforreduction,thefollowing methodareused:methodofreducingthecharging volumeu8edintheblastingofonetimeandmethod orincreaSlngnumberDfstepsofdelaytimeblasting.

Howeverinthesemethods,theworkerrICiencyof b]a8tingwillbelower,andtheoperationco8tS inerea8e.Thererbre,bycontrollingtheinitiation timepreciselywiththepreciseblastingmachine. thereductionmethodofblastingvibrationu81ng interferencephenomenonofblastingvibrationwas studied.Inthi8method,thevibrationreduction wasexaminedbytheinterferenceorgenerating vibration.InAddition,theresultiSgoodfrom PMMAphtemodeltestbythemortarblockand smallscaleexperimentorprotectivewalllk'･11e8t blastingwasCarriedoutontheApPlicabilityof vibrationreductionmethodbytheinitiationtime controlmethodtothequarry.

2,Theprincipleofthevibrationreduction TheprlnCip)eorthevibrationreductionmettlOd oftheblastingvibrationbytheinterferenceis accordingtotheroIlowlng.Forexampletheblasting

‑3/‑2‑ 火薬学 会誌

0

0

(‑)VitlratjoTIVaYerOrmdeflr)edasthttri等OnOmelrkrunct如 l I

′ヽ l

′ヽ 一ヽ

一 ヽ

′ l

′ l

l

l

′ハ､､､

/ ､､､､ノ

′′

ヽ^ー

l I

0 (b)Vibrltio5rtdda0 yedtheh)r‑cIde100 15

ForYihraIiorHaJ ノヽ

′ ヽ

一 l ′ヽ

ノ ゝtt. !Jヽ′ヽ′ヽ′ '∠′ ＼ゝ7､､JJ ′ ､

t.^J‑‑JI.

ノ･･

ノ

0

100 150

(clsuprirrLPOSedwaydl)rT

T)Ortl)artdlhl

Fig.1Principleorthevibratio

nreductionmethod by

theinLerlerence

vibrat.ionafI8umeSthevibrationw

.TIVefornlder)ned a8thetrigonometricfunctionwh

ichattenuEIte8in therlXedperiodshowninFig.1.

Whenthevibration waveform (a)isSuperimpose

dbythevibration waveform(h)delayedthehalf‑cy

clefrequencytime inFig.1,theLImplitudeorthei

nterferedwaverorm i.qreduced.Thefirstpeakampl

itudeofb)fISting vibrationbecomesahalrlessthan

I.heca鍔einwhich thereare88meWaVeform at

theSametime,and thevibrationcanbereduced.fl

owever,inactuFIl blastin^g,thewaveform ofbla

stingvibrationi8 complicated,anditisnote

asytodecidetime

difference.Therefore,themethodfordecidingthe optimum timedifferenceusi

ngthecorrelation funct.ionwasexaminedand

thegoodreSulLby modeltest.swasobtained.Corre

lationfunctionand optimumtimedirrerencebyfreq

uencyanaly8iSare theoreticallySame.Theme

thodtodecidethe optimumtimedifferencebythe

frequencyan且)y^Si⁸ methodoutofcon8ider8tirlnOf

applicabilitywith fieldwasexamined

, 3,Experirnent 3.1E

xperimentalmethod Therteldexperimentwasused

theblastingbench (bencllheight:about5m)Orthe

quarryunderwork atpresent.Theblastingdesignwa

stakenasfollows; intervaloftheblaRtholei82m

and10holesStage x4stage,lineorleastresif;tanCe

is2m,blasthole diameter65mm,theblastinginit

iationtimeofthe experimentseteachStageatth

edifferencetime.

Thesummaryortheblastin

gdesignforthese experiments

i8ShowninFig.2.

The18tSL叩elOholeswasCO

nneCtedintheone initiationcircuitanditinitiated

inorderfromthe firststagetothefinalstage

uslngtheprecise initiationmachine(initiat

ioncircuit:5ch, initiationaccuracy:Ips,Sett

ingtime:1L18 ‑

10S,charglI哨 VOltage:ove

r2500V,condenser capacity:1pF/ch,outputcurren

t:overlkA)made hyNipponK8yakuCo.,Ltd..

lntheexperiment, thefollowlr咽tWOkinds0rdeton

atorwereusedAnd I,hediLrerencewasextLmined:Tnsta

ntaneou8elect.ric detonatorandelectricdet.o

nat.orfor8ei8mic exploration.ANFO explos

ive7.2kgcharglng volumewasusedforeachhole.Th

eslurryexplosive 0.2kgwasusedaStlboosterfor

theinitiationor ANFO explo8ive,Theblas

tingwaveform was measuredu8ir岬theaccelerome

terwhichwereSet inthefield(50‑230m)betweentheinitiationpoint

andfrontrace.

3.2 Decision method forthe optimum t ime difference.

Intheexperiment,there

ferentialblasting vibrationgeneratedhytheblasti

ngof10holesper 1stageismeasuredinorderto

decidetheoptimum timedifferenceattheb

eginning.Thetime differenceorinitiationfor

eachblastingwas calculatedfromthefrequencyana

lysisofreference KayakuGakkaishi.Vol.63.No.6.

主 よ ^主 主 よ

chl(lstage)

CJ12(2slage) CJ73(3slage) cJ14(4slage)

Fig.2B188tingdesignforexperiments blaStirLgVibration.Simultaneously,atime

differencea8themo白tnegativecorrelatio n AccordingtoautOCOrrelationfunctionofblas

ting waveform wasalsoobtained.Theoptimum time d

ifferenceforvibrationreductionmethodwas examine

dfromthesereSult8. 4.ResultS

4.1Analytical

resultofreferentialbJast‑

ing vibration Thewa

veform generatedinthebla8tingof10 holes

perIStageaSareferentialwaveformiBShown infig.3(a).Re8ult80fautocorrelationfunct

ionand frequencyanalysisofthisvibratio

nareShownin Fig.3(b)(C),ThemaxiJnum freq

uencybythe frequencyanalysisresultbecameabout

22.5Hzand theinitiationtimedifferencebecame22

.2ms dirrerence̲Thistimedifferencealsobecam

ea negativevalueintheanalystsaccordingto autocorrelationfunction.From these

results,the vibrationreductionbytheinterference

ofwaves canbeexpectedbySettinganinitiati

ontime differencewith 22.2m8.Theexperimentofth

e10 holes8tageX 4stagesblastingdesignwas

Cami ed outontheoptimumtimedifferencetobe22

.2ms. tnblastingvibrationreductionexperiment

by usingthewaveinterferencemethod,itwasm

ade

tobeaninitiationtimedifferenceoffirstStage =Oms,8eCOnd8tage=22.2ms,thirdStage=4 4.LIms, fourth

(a)ReferentialwaVeformofb188tingvibration

0 10 20Time(ns30 40 50 )

Lb)R朗ultorautOCOrrelationfunctiona nalysis forreferen

tialwaVerrOm

A ■l■■

Hl ■l‥Hl

.l‥ Hl .l日日l

100 Fr1e01q 102 (Hz)

lc)Re

sultoffrequencyanalyBiSforreferential waVefb

rm

Fig.3ResultoranalySisforblaStingvibration reductioneqectwillbeobtained.Itcanbeestimat ed thatthevibrationreductioni8moreeffectively

on farfrom theinitiationpointfrom theanal

ytical result.Itcanbeestimatedthatthevibr

ation reductionbytheSettingoftheinitiationtim

e dimorffereeefncrccteaiveccloytrdihanbngtotytheche8oerLtrielngoatiftonfheunctioniS initiation timedifferencebythefrequency

result. 4.3

Vibration reductionresultbythewave inter

ference

Theblastingexperimentorthe 10hole s of4

JL E5't

)

!tu

一 ヽ l H

HH

● △○○ ● ム09 +t d& ● 台

0 ● … ● 各 ●

0

●

△○ DIIbnFflrI) )

隻 語 FEP･.ii

艶

Fig.40Referencevib

ration(1Stage)

●simultAneou8

initiation(4Stage)

△Frequency&n81y8i8

(48tAge)

◎correlationfunction8nAly8iS(4Stage)

Z

Fig.50Referencevibration

(1stage)

●Controllinginitiationtime(4st age) 8tageSWasCarriedoutchan由ngtheoptimum

time diWerenceoreachlinewith22.2msobtainedb

ythe analyticalresultorreferentialwavefor

m.The analySi80freferentialwaVeform generated

by instantaneouselectricdeton8tOranddetona

torfor BeiSmicexplorationw88almost8imi lar.Itwas shownthatiti8abletoinitiatebytheinstantaneo

us electricdetonatoratthe8ccur8CysumC

iently.The each blastinglinewasinitiated from

the measurementOfvibrationw8VeformtotheSett

ing way,anditi8proventhattheblastin

gvibration hasinterferedeachwaverorm.Thema