花岗岩地区地铁隧道爆破振动传播规律研究

VIBRATION PROPAGATION OF TUNNEL BLASTING IN GRANITE AREAS

青岛为典型花岗岩地区,地铁隧道开挖采用钻爆法.本文首先采用现场实测与统计分析的方法分析了青岛地铁3号线3个工点的隧道爆破监测数据,较为系统地研究了钻爆法施工条件下地表及邻近构筑物的最大振速、主频分布与爆破参数的相关关系,采用线性回归法拟合出包含上述因素的经验公式.采用数值模拟手段,模拟爆破条件下地表及临近建筑物的振动的响应,并将模拟结果与实测数据进行对比,研究主要结论如下（1）最大振速随比例距离基本呈指数的形式衰减,随着比例距离的增加,最大振速值逐渐减小;（2）爆破引起的振动主频随比例距离分布较为随机,无法建立两者之间的数学模型,主频多在20～70Hz范围内;（3）建筑物内部中三矢量方向上的最大振速均随着楼层的增高呈-定的增加趋势,建筑物外部的地表振速要大于内部质点的速度.

Qingdao is the typical granite region,which uses the drill and blast method to the excavate tunnel. Firstly,the article analyzes the measured blasting data of 3 work site which belong to Qingdao Metro Line 3 using field measurement and statistical analysis.The correlation between vibration velocity of surface and neighboring buildings and the frequency characteristics caused by blasting of blasting distance and dose were researched.The empirical formula including the above factors was concluded by regression analysis.The numerical modeling method was used to research the influence of blast to surface and neighboring buildings,and the simulate particle vibration data was compared with the measured by numerical simulation.The main conclusions are as follows:(1 )with the increase of blasting distance,the maximum vibration velocity of surface particle decreases in the form of index attenuation.(2)the vibration frequency caused by blasting is distributing randomly with scaled distance,therefore it is unable to establish the mathematical model between them,and the dominant frequency mostly ranges from 20 to 70 Hz.(3)with the stories increase,the maximum vibration velocity of three-vectors has the magnifying trend.The maximum vibration velocity of the particle inside the building is generally less than the particle closing to the building exterior surface.