It is important to control overexcavation
and underexcavation and reduce blasting disturbance to
surrounding rock in blasting construction of karst tunnel. To optimize smooth
blast parameters, tunnel blasting model is established with finite element
software LSDYNA, and the effects of blasting
parameters such as periphery hole space, resistance line size, and linear
charge density on smooth blast in karst tunnel are studied. After comparing the
damage thickness and equivalent stress of surrounding rock under different
blasting parameters, a blasting optimization method for karst tunnel is
proposed and its application in Daliangzi tunnel shows that: for the tunnel
excavation with vault karst cave in grade Ⅲ limestone,
if the periphery hole space is reduced from 45 cm to 40 cm, resistance line
size reduced from 70 cm to 60 cm, and linear charge density adjusted from 0.150
kg/m to 0.125 kg/m, the influence of karst cave on smooth blast can be reduced,
the engineering cost caused by overexcavation and
underexcavation can be cut down, and the blasting
disturbance to surrounding rock can be reduced, which improves the overall
stability of the tunnel.
LIU Guoqiang, LIU Bin, ZHANG Qingming, ZHANG Ruilin, HUANG Feng, TONG Xiaodong
. Parameter Optimization of Smooth Blast in Karst Tunnel
and Its Application[J]. Tunnel Construction, 2021
, 41(S2)
: 50
-57
.
DOI: 10.3973/j.issn.2096-4498.2021.S2.006
