In the intricate world of underground construction, where precision and safety are paramount, a recent study has shed light on the delicate dance of blasting excavation and its impact on adjacent tunnels. Led by WANG Xubin from the Department of Underground Architecture and Engineering at Tongji University, along with colleagues YANG Zhenye and HUANG Ning from Shanghai Foundation Engineering Group Co., Ltd., the research delves into the dynamic response and safety control of adjacent tunnels during blasting excavation, particularly in coastal saturated tuff bodies.
The study, published in ‘Yantu gongcheng xuebao’ (translated to English as ‘Rock and Soil Mechanics’), focuses on the challenges posed by parallel blasting excavation of tunnels in close proximity. “In such scenarios, the construction of new tunnels can cause varying degrees of vibration damage to the linings of adjacent tunnels due to the small tunnel spacing,” explains WANG Xubin. This phenomenon is particularly relevant in the energy sector, where underground infrastructure is crucial for operations and safety.
The research team conducted real-time monitoring of vibration responses in adjacent tunnels during the blasting excavation process. They also performed numerical simulations to better understand the blasting vibration response. Their findings revealed that in a saturated tuff medium, the dynamic response of the adjacent tunnel to the surrounding hole is most significant at the arch of the blasting side. The vibration frequency was found to be concentrated in the 0~50 Hz range.
One of the key takeaways from the study is the importance of controlling the single-hole charge length and tunnel spacing of peripheral holes. The researchers recommend keeping these parameters below a 1:20 ratio to minimize vibration damage. “This ratio is critical for ensuring the safety and integrity of adjacent tunnels during blasting excavation,” notes YANG Zhenye.
The implications of this research are far-reaching, particularly for the energy sector where underground tunnels are essential for various operations. By understanding and mitigating the vibration effects of blasting excavation, construction companies can enhance safety, reduce potential damages, and optimize project timelines. This study provides valuable insights that could shape future developments in underground construction, ensuring more efficient and safer practices.
As the energy sector continues to expand and evolve, the need for robust and reliable underground infrastructure becomes increasingly important. The findings from this research offer a significant step forward in addressing the challenges associated with adjacent tunnel construction, paving the way for more advanced and safer excavation techniques.