FBG传感器监测钻爆对邻近隧道衬砌结构的影响

新隧道的施工爆破产生的地震波会影响邻近既有隧道衬砌结构的安全和稳定。结合新建碧鸡关隧道实际工程,应用15只光纤Bragg光栅(FBG)表面应变传感器对既有碧鸡关隧道衬砌表面迎爆侧进行了8次爆破和3次列车通过时的应变监测,研究了爆破对邻近隧道衬砌表面应变变化的影响。2010年6月23日爆破药量为129 kg,爆破量为中等,爆破对衬砌表面的应变产生了明显的波动影响,引起传感器在发生爆破前后出现数据突变,应变最大变化量在35×10-6~43×10-6之间。当列车通过碧鸡关隧道时,衬砌表面的应变变化较小,应变最大变化量在9×10-6~12×10-6之间。

Effect of drilling and blasting lining monitored on structure of nearby tunnel by FBG sensor

The seismic wave caused by blasting in new tunnel＇ s construction will influence safety and stability of adjacent existing tunnel lining structures. Combining new construction of Bi Ji Guan tunnel project and use strain sensors on 15 fiber Bragg gratings （FBG）surface to monitor strains, which caused by 8 times of blasts and 3 times of train gets through respectively of Bijiguan tunnel lining surface of the blasting side. Influence of blasts on strain surface of adjacent tunnel lining structures is also studied. On June 23,2010, explosive is 129 kg which is medium, and blasts produced obvious fluctuations about strains on the surface of lining structures and caused data mutation in the sensors after blasting, and the maximum mutation is between 35 × 10 -6- 43 ×10 -6. When the train is passing through the tunnel,the maximum mutation is between 9 × 10-6-12 × 10-6.