摘要:
利用钻爆法开挖山区双线隧道时,后行隧道施工会不可避免地产生不利的振动效应,从 而影响到先行隧道的安全稳定。 相邻隧道爆破的振动测试与分析,对双线隧道的安全施工有着 重要意义。 本文以兴延高速公路浇花峪双线隧道工程为背景,对隧道轴线进行了现场振动测试, 得出了以下结论:①相邻隧道测试区域内三方向振动强度大小依次为垂直方向、水平径向、水平 轴向;随着爆心距的增加,三方向间的振动强度差异逐渐减小。 ②掏槽炮孔的夹制作用最大,同 时爆破振动强度亦最大。 ③不同类型炮孔爆破振动波形都存在迅速从初始值上升至振速峰值, 而衰减过程相对较慢的现象,且这种现象在掏槽孔爆破时尤其明显。 ④在双线隧道爆破施工时, 降低掏槽孔的最大单段药量、增加雷管段别、分解隧道开挖断面、控制爆破规模等是减小爆破振 动的有效方式。
Abstract:
Whenthetwo-lanetunnelinthemountainousareaisexcavatedbythedrillingandblasting method,theconstructionofthereartunnelwillinevitablyproduceunfavorablevibrationeffects,thusaffectingthesafetyandstabilityoftheprecedingtunnel.Therefore,thevibrationtestandanalysisofadjacenttunnelblastingisofgreatsignificanceforthesafeconstructionofdouble-linetunnels.Inthispaper,basedon the two-line tunnel project of the Xingyan Expressway,the following conclusions ard drawnbyconductingon-sitevibrationtestsonitstunnelaxis:①Therelationshipbetweenthethreedirectionsofvibrationintensityintheadjacenttunneltestareais:verticaldirection>horizontalradial> horizontalaxis,andthesizerelationshipisrelativelyfixed.Astheblastingdistanceincreases,thedifferenceinvibrationintensitybetweenthethreedirectionsgraduallydecreases.②Theclampingofcutting holeisthebiggestandtheblastingvibrationintensityisthebiggest.③Theblastingvibrationwaveforms
ofdifferenttypesofblastholeshaveaphenomenonofrapidlyincreasingfromtheinitialvaluetothe peakvalueofthevibrationvelocity,andtheattenuationprocessisrelativelyslow,andthisphenomenon isparticularlynoticeableintheblastingofthecuthole.④Inthedouble-linetunnelblastingconstruction,reducingthemaximumsingle-stagedoseofthecuthole,increasingthedetonatorsection,decomposingthetunnelexcavationsection,andcontrollingtheblastingscaleareeffectivewaystoreducethe blastingvibration.
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