100m高烟囱拆除爆破冲击振动测试与分析

在新乡电厂百米钢筋混凝土烟囱爆破拆除工程中,布置了不同方向的两条测线共9个测点,量测了爆破和烟囱倒塌触地引起的地面质点振速和主振频率。从实测数据的分析认识到:烟囱顶部落地产生的冲击力最大,线状震源正前方测点的振速比其侧向测点的振速要大;烟囱倒塌触地产生的振动是各段筒体所产生的振动的叠加,它与各分段体的质量、位置高度、材质强度等因素有关;高大建(构)筑物落地冲击地振动的频率一般比爆破引起的地振动的频率要低;铺设缓冲材料、分段爆破等措施可减小触地冲击引起的地面振动强度。此外,利用实测数据进行拟合,得出了适用于描述本工程烟囱倒塌触地冲击地振动衰减规律的经验公式。

MONITORING AND ANALYSIS OF IMPACT VIBRATION CAUSED BY TIPPLING OF A CHIMNEY WITH HEIGHT OF 100 METERS

In the project of demolishing a reinforced concrete chimney with height of 100 meters in Xinxiang Power Plant by blasting, two measuring lines with a total of nine measuring points were arranged and velocities and dominant frequencies of ground particle vibration from blasting and chimney touchdown were measuredIt is known from the analysis of measured data that the maximum impact is from touchdown of chimney top,the vibration velocities of measuring points at direct front of a linear vibration source are larger than that of measuring points at the side of the source,the touchdown vibration caused by the collapsing of a chimney is the repeated addition of the touchdown vibration of its sections and relative to mass,elevation,material strength of every section,the frequency of touchdown impact vibration of tower like constructions is lower than that of blasting vibration,and the intensity of the touchdown vibration can be reduced by use of some technological measures such as buffering material laying and sectional blastingIn addition,the empiric equation suitable to describe the attenuation law of ground vibration resulted from the chimney touchdown is worked out by a fitting method based on measured data