• BLASTING
  • Vol. 39, Issue 3, 82 (2022)
LI Guang-tao and LI Da-chun
Author Affiliations
  • [in Chinese]
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    DOI: 10.3963/j.issn.1001-487x.2022.03.012 Cite this Article
    LI Guang-tao, LI Da-chun. New Development Stage of Water Pressure Blasting Technique in Tunnel Excavation[J]. BLASTING, 2022, 39(3): 82 Copy Citation Text show less

    Abstract

    In tunnel driving blasting,the construction technique of replacing the stemming material or charge decks with water is also called water pressure blasting.The development of charge structure in tunnel blasting can be divided into three stages,from basically bottom initiation without stemming to stemming with solids or water at the hole collar,then to the present technique of water cushion,isolation and plugging in multiple parts of the hole.The first stage is from 2002 to 2015,when the main charging structure was based on the conventional charging structure.The hole was stemmed and both bottom and the collar of the hole were padded with a water bag,and the charge of the hole was reduced.The second stage is from 2016 to 2020.The main technological progress was that the charge section in a smooth blasting hole was replaced by a shaped tube device,which improved the half cast factor and reduced the number of smooth blasting holes.The new stage is from 2021 to now,with the new Meizhou to Longchuan railway Hegongtang tunnel as a representative project.In this project,water bags were used for decks and stemming instead of solid stemming materials.And the length of the water bag was increased from 20 cm to 60 cm.Practice proves that compared with conventional blasting technology,this new blast technique not only saves 25% of the explosive and reduces the workload of the smooth blasting holes,but also improves the efficiency of charging operations and the dust removal effect.
    LI Guang-tao, LI Da-chun. New Development Stage of Water Pressure Blasting Technique in Tunnel Excavation[J]. BLASTING, 2022, 39(3): 82
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