Controlled blasting technology for high slope excavation in existing railway expansion
The excavation of high and steep slope for cutting expansion has always been a major concern in the reconstruction of existing railway line.To achieve safe and efficient excavation,the blasting restrictions were completely analyzed,and the shallow hole blasting with large blasthole diameter and wide spacing was adopted in the excavation of narrow and steep slope,without the separately reserved rock wall for secondary blasting.After more than 20 rounds of blasting,the excavation of the high and steep slope was safely and efficiently completed,without any accidents such as flying rocks,rolling rocks invading the line,and injuring people.The maximum blasting vibration velocity monitored was 1.28 cm/s,meeting the requirements of precisely controlling blasting.This adopted technology achieves precise control of the blasting fragmentation range by controlling the single blasting height and the horizontal distance between the outermost blasthole and the slope surface.It successfully controls the rolling rocks on the slope while achieving efficient blasting excavation,indicating that the shallow hole blasting with large blasthole diameter and wide spacing can replace the inefficient shallow hole blasting that usually requires small blasthole diameter and reserved rock wall under appropriate protective measures.The results can provide certain reference and inspiration for similar projects.
controlled blastingexpanding cuttinghigh and steep slopelarge-diameter borehole
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