摘要
为探究隧道施工爆破振动对隧道二衬新浇筑混凝土的影响,以Ⅳ级围岩台阶法施工的上台阶掌子面爆破作为震源,对不同新浇超短龄期的4个等级强度的混凝土试块分别在不同爆心距下进行爆破振动试验。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普通混凝土试块中的传播速度,通过对两者传播速度进行对比分析,判断爆破受振混凝土试块的缺陷与损伤程度。研究结果表明:在Ⅳ级围岩上台阶施工情况下,爆心距为15 m处的混凝土试块受爆破振动的影响最大,在30 m处的混凝土试块具有最强抵抗爆破振动的能力,30 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、确保隧道施工安全提供参考。
In order to explore the influence of blasting vibration in tunnel construction on newly poured concrete of the second lining of tunnel,taking the blasting of upper bench face of stage IV surrounding rock bench construction as the source of vibration,blasting vibration tests were carried out on four kinds of concrete blocks with different strengths of different newly poured ultra-short ages at different spacings of blasting centers.After 28 d of curing,non-metallic ultrasonic testing instrument was used to test the propagation speed of ultrasonic wave in vibration concrete and ordinary concrete.Through the comparative analysis of the propagation speed,the defect and damage degree of the blasting vibration concrete were judged.The results show that under the condition of step construction in grade IV surrounding rock,the concrete blocks with a distance of 15 m from the blasting core are most affected by blasting vibration,and the concrete blocks with a distance of 30 m have the strongest ability to resist blasting vibration.Beyhond 30 m,the damage of blasting vibration to the concrete blocks is less and tends to be stable.The conclusion provides a reference for shortening the distance between the second lining and the face of tunnel to ensure the safety of tunnel construction.
作者
贺泳超
陈秋南
衣利伟
黄向韬
曾奥
周相识
周光裕
HE Yongchao;CHEN Qiunan;YI Liwei;HUANG Xiangtao;ZENG Ao;ZHOU Xiangshi;ZHOU Guangyu(School of Civil Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;Hunan Provincial Key Laboratory of Geotechnical Engineering for Stabilility Control and Health Monitoring,Hunan University of Science and Technology,Xiangtan 411201,China;Hunan Communication&Water Conservancy Group Ltd,Changsha 410022,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第2期507-513,共7页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(41372303)
湖南交通科技创新项目(201712)~~
关键词
爆破振动
超短龄期混凝土
超声波检测
混凝土缺陷
blasting vibration
ultra short age concrete
ultrasonic test
concrete defects
