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- Title
循环冲击荷载下机制砂喷射混凝土动力特性研究.
- Authors
刘仲阳; 王新宇; 李庆东; 李鹏飞; 王俊波; 宋 林
- Abstract
In the drill-and-blast construction of a new tunnel, the manufactured sand shotcrete supporting structure of the adjacent existing tunnel would be subjected to cyclic impact load. In order to study the effect of axial compression on the dynamic properties of the manufactured sand shotcrete under cyclic impact load, a modified large-diameter split Hopkinson pressure bar (SHPB) test system is employed to conduct cyclic impact tests on the manufactured sand shotcrete under four axial compression levels, and its dynamic properties under cyclic impact load are analyzed. The results reveal that the axial compression and impact velocity have great influence on the failure mode, peak stress, peak strain and strain rate of the manufactured sand shotcrete and the increased axial compression helps effectively inhibit the deformation of the specimens. Under the same axial compression, the higher the impact velocity, the less the impact cycles required for specimen failure. At the same impact velocity, the number of impact cycles required for specimen failure grows with the increase of axial compression. When the impact velocity and axial compression remain unchanged, the peak stress and dynamic elastic modulus of the specimen decrease with the increase of impact cycles, while the peak strain and strain rate increase. The axial compression shows no significant effect on the dynamic elastic modulus of the specimens. As more impact cycles are applied, the cumulative specific energy absorption value of the specimens increases linearly. At the same impact velocity, the larger the axial compression, the larger the cumulative specific energy absorption value required for specimen failure. In other words, the increase of axial compression can significantly increase the energy dissipation capacity of the specimens, thus slowing down deterioration of the mechanical properties of the specimens.
- Publication
Railway Standard Design, 2024, Vol 68, Issue 4, p153
- ISSN
1004-2954
- Publication type
Article
- DOI
10.13238/j.issn.1004-2954.202208240009