硫酸盐结晶作用后深埋公路隧道安全性能

Impact from sulphate crystallization to the safety of deep highway tunnel

对衬砌受盐结晶破坏后Ⅳ级围岩中埋深为30 m的隧道,运用同济曙光软件建立荷载—结构法拉压弹簧模型进行分析计算。计算表明:1)由盐结晶造成的隧道衬砌劣化,对病害处衬砌的力学性能影响较大,对无病害处衬砌的力学性能影响较小;2)无论是裂缝还是剥落病害,拱顶处的病害对隧道安全性的影响要比拱腰处的大,起拱线处的剥落病害对隧道安全性的影响也不容忽视;3)隧道衬砌同样位置发生剥落病害或裂缝病害时,剥落对隧道整体安全性的影响程度比裂缝大。

Applying GeoFBA,generates a load-structure method for analyzing and calculating the tunnel,which is 30 m-depth-embedment surrounding rock Ⅳ and influenced by sulphate crystallization.The calculation demonstrates that primarily,combined action of sulphate and cycles of freezing and thawing perhaps cause a deterioration to the tunnel lining and this phenomenon affects mechanics function of lining where it has some defects more than the one has not defects;moreover,no matter if a crack or spalling happened,the influence to tunnel safety reveals bigger when it has problems on the arch crown than in the haunch;moreover,it should not be ignored that spalling in the springing line could cause the threats to tunnel safety either;Finally,influence caused by spalling to the entire safety of tunnel is greater than that caused by crack.