ISSN 2096-4498

   CN 44-1745/U

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Study on Blasting Technology for Large Crosssection Hard Rock Tunnels:  Case Study on Fengning Tunnel

  • LI Dachang ,
  • ZHANG Junbing ,
  • SUN Bole ,
  • ZHENG Baocai
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  • (China Railway No. 3 Engineering Group Co., Ltd., Taiyuan 030001, Shanxi, China)

Received date: 2015-02-11

  Revised date: 2015-04-08

  Online published: 2015-08-24

Abstract

With 120 m2 crosssection area, Fengning tunnel has 4 063 mlong section located in Grade Ⅱ surrounding rock. In the paper, two parallel cuthole schemes, i.e., scheme with the central holes being empty and scheme with the surrounding holes being empty, for the Grade Ⅱ surrounding rock section of Fengning tunnel are simulated by means of ANSYS/LSDYNA finite element program, and the transmission rules of the blasting stress waves and the rock destruction conditions are analyzed, which concludes that the scheme with the central holes being empty is the favorable scheme; appropriate parameters are determined for the contour holes on basis of the smooth blasting technology; the blasting effect is assessed on basis of the field observation data. Conclusions drawn are as follows: 1) The design of "parallel cut hole with the central holes being empty+appropriate blasting parameters" is rational; 2) The numerical simulation technology can reduce the cost effectively. The study result can provide reference for similar projects in the future.

Cite this article

LI Dachang , ZHANG Junbing , SUN Bole , ZHENG Baocai . Study on Blasting Technology for Large Crosssection Hard Rock Tunnels:  Case Study on Fengning Tunnel[J]. Tunnel Construction, 2015 , 35(8) : 846 -850 . DOI: 10.3973/j.issn.1672-741X.2015.08.016

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