Dynamic Response of Composite Support Structures Under Different Blasting Methods for TBM Breakout
(1. State Key Laboratory of Geohazard Prevention and Geo-environment Protection, Chengdu University of Technology, Chengdu 610059; 2. Sichuan Engineering Technology Research Center of Complex Geology TBM Intelligent Excavation and Disaster Prevention, Chengdu 610059)
Abstract：
To systematically and quantitatively analyze the dynamic response characteristics and safety ranges of support structures under different blasting methods for releasing a double-shield TBM (shield body) jammed in high-stress hard rock, this study takes the TBM jamming section in the Duoxiongla Highway Tunnel as an example.Numerical models were established using SolidWorks and Hypermesh, and LS-DYNA was employed to calculate and analyze the dynamic effects of millisecond-delay blasting on support structures under high geostress. Based on this, with peak particle velocity (PPV) as the key indicator, the advantages of millisecond-delay blasting over simultaneous blasting were investigated, and the safety ranges of support structures under different blasting loads were delineated. The results show that the maximum PPV of the support structure occurs near the center of the blasting zone and gradually increases with the advance depth of blasting, with the occurrence time advancing correspondingly. Notably, the 5th and 6th blasting advance rounds exhibit significantly higher PPVs than other advance rounds. Compared to simultaneous blasting, millisecond-delay blasting effectively reduces the dynamic impact of blasting loads on composite support structures. For the 5th and 6th blasting advance rounds, millisecond-delay blasting reduces PPV by up to 42.3%, significantly shrinking the unsafe range of the support structure.
2025, Vol. 62 