山岭隧道爆破振动对新浇超短龄期混凝土二衬的影响  

Influence of blasting vibration on newly poured ultra short age concrete secondary lining in mountain tunnel

作　　者：胡锦华 HU Jinhua(China Railway Sixteenth Bureau Group Co.,Ltd.,Beijing 100018,China)

机构地区：[1]中铁十六局集团有限公司,北京100018

出　　处：《混凝土》2021年第9期149-152,160,共5页Concrete

摘　　要：为研究爆破振动对于山岭隧道中新浇超短龄期混凝土二次衬砌的影响,将中心爆破点定在隧道施工中掌子面处,对6~72 h共计5组不同新浇超短龄期的C40强度等级混凝土试块分别在不同爆破心距下进行爆破振动试验,试验测定5个测点三相合成振速。待所有试块养护28 d后,采用非金属超声检测仪分别测试超声波在受振混凝土试块和标准混凝土试块中的超声波传播速度,对比分析受振与标准试块内部超声波传播波速,探究受爆破振动混凝土试块的损伤程度与振速V振动、混凝土龄期d及爆破距离L的关系。经检测分析数据结果可知:模拟隧道爆破振动试验中,距离爆破中心L=12 m时的混凝土试块损伤情况受爆振影响最大;在25~35 m区间内的混凝土试块具有最强抵抗爆破振动的能力,55 m之后爆破振动对混凝土试块的损伤较小且逐渐趋于稳定。这可为缩短二衬至掌子面距离、明确最大爆破振动速度,确保山岭隧道施工安全提供了一定参考。In order to explore the influence of blasting vibration on the secondary lining of newly poured ultra short age concrete in mountain tunnel construction,the blasting vibration tests were carried out on the four grade strength concrete blocks with different newly poured ultra short age under different blasting center distances by taking the upper bench face blasting of C40 surrounding rock bench method as the source.After 28 days of curing,the non-metallic ultrasonic detector was used to test the ultrasonic propagation speed in the vibrated concrete block and the ordinary concrete test block,and the defect and damage degree of the blasting vibration concrete test block were judged by comparing and analyzing the propagation velocity of the two.The research results show that in the case of construction of upper bench in surrounding rock,the concrete block with a distance of 12 m is most affected by blasting vibration,and the concrete block at 25 m has the strongest ability to resist blasting vibration.After 55 m,the damage of blasting vibration on concrete block is small and tends to be stable gradually.This can provide a reference for shortening the distance from the second lining to the tunnel face and ensuring the safety of mountain tunnel construction.

关 键 词：山岭隧道 爆破振动 新浇混凝土 超短龄期 二衬 

分 类 号：TU528.01[建筑科学—建筑技术科学]