为控制岩溶隧道爆破施工过程中的超欠挖质量，降低爆破对隧道围岩的扰动，有必要开展光面爆破参数优化研究。采用有限元软件LS-DYNA，建立隧道爆破模型，研究岩溶隧道中不同周边孔间距、抵抗线大小及线装药密度等爆破参数对光面爆破效果的影响，分析不同周边眼爆破参数下的围岩损伤厚度及围岩等效应力，提出一种针对岩溶隧道的爆破优化方法。结合大梁子隧道的应用研究，结果表明：
对于Ⅲ级灰岩遇拱顶溶洞的隧道开挖，将周边孔炮孔间距从45 cm下调到40
cm，周边孔抵抗线从70 cm下调到60 cm，同时将周边孔线装药密度从0.150 kg/m调整为0.125 kg/m，既能有效改善溶洞对光面爆破效果的影响，减少由超欠挖导致的工程成本增加，也可减少爆破对围岩的扰动，提高隧道整体稳定性。
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.
