窗洞口传热
heat transfer loss of window surrounding
洞口不良地质段
Tunnel Portal in Unfavourable Geological Section
洞口段施工
Construction of the entrance
Portal construction
Portal section construction
洞口附加钢筋
additional bar around opening
洞口改造
hole mouth transformation
洞口偏压
asymmetrical-loaded portal
洞口气温
Tunnel portal temperature