隔振沟对爆炸塔周边地表振动的影响

对内径2m、壁厚0.4m 的椭球封头爆炸塔进行有、无隔振沟条件下的对比爆炸实验,并监测塔体周边6个测点的地表竖向及水平方向的振动速度。研究结果表明:地表质点的振动持续时间小于0.2s,竖向振动频谱在20~500Hz范围内,水平方向振动频谱则在200~800Hz范围内;隔振沟使水平方向振动幅度衰减至原来的1/10,对竖向振动幅度衰减至原来的1/4~1/3,对地表振动频率无明显影响;爆炸塔隔振沟的深度为1m 时,对爆炸地震波无任何衰减作用,仅当深度达到1.5~2.0倍瑞利波波长时(5.6~7.5m)才会产生明显的隔振效果。

Effects of vibration-isolating trench on ground vibration surrounding blast containment chamber

Aseriesofblastexperimentswithandwithoutvibration-isolatingtrencheswereimplementedintheblastcontainmentchamberwithanellipticconewhichhavinganinsidediameterof2mandawallthicknessof0.4m.Andtheverticalandhorizontalgroundvibrationvelocitiesat6differentpointsonthesurroundinggroundofthechamberweremeasured.Theexperimentalresultsshowthatthegroundvibrationdurationislessthan0.2seconds,thefrequencyspectraoftheverticalandhorizontalvibrationsareinthe20-500Hzand200-800Hzranges,respectively.Thehorizontalvelocityamplitudesafterattenuationbythetrenchesareone-tenthofthosebeforeattenuation,aswellasonefourthtoone-thirdfortheverticalvelocityamplitudes.Butthetrencheshavenoobviouseffectonthefrequencyspectraofthegroundvibrationwaves.Thevibration-isolatingtrencheswith1mdepthhavenoattenuationeffectontheblastseismicwaves,buttheattenuationeffectwillberemarkablewhenthedepthsofthetrenchesare1.5-2.0timesaslongasthewavelengthsoftheRayleighwaves.