高烈度地震区隧道洞口段纤维混凝土衬砌抗震效果分析

Anti-seismic Effect of Fiber-reinforced Concrete Lining at Tunnel Portals in High-intensity Seismic Areas

为提高隧道洞口段衬砌结构的震时安全性,以某公路隧道洞口段为研究背景,利用有限元分析软件ABAQUS,对使用钢纤维混凝土(SFRC)、钢-玄武岩混杂纤维混凝土(SBHFRC)与素混凝土作为二次衬砌结构材料时的抗震效果进行对比分析。结果表明:在同体积纤维掺量的条件下,与素混凝土二次衬砌相比,SFRC二次衬砌的最大、最小主应力峰值分别增加34.27%、23.56%,剪应力峰值增加23.54%,SBHFRC二次衬砌的最大、最小主应力峰值分别增加3.90%、3.37%,剪应力峰值增加3.32%;SFRC、SBHFRC二次衬砌结构的等效位移分别减少了8.08%、2.36%;SFRC、SBHFRC二次衬砌结构监测面各监测点平均安全系数分别提高了38.73%、50.04%。

In order to improve the safety of tunnel portal lining structure during earthquake, taking the portal section of a highway tunnel as the research background, it carries out comparative analysis with the finite element analysis software ABAQUS on the anti-seismic effects of steel fiber reinforced concrete(SFRC), steel-basalt hybrid fiber reinforced concrete(SBHFRC) and plain concrete as secondary lining structure materials. The results show that:(1)compared with plain concrete lining, under the condition of the same fiber volume content, the maximum and minimum principal stress peaks and shear stress peaks of SFRC secondary lining are increased by 34.27%, 23.56% and23.54% respectively, while those of SBHFRC secondary lining are increased by 3.90%, 3.37% and 3.32% respectively;(2) the equivalent displacements of SFRC and SBHFRC secondary lining structures are reduced by 8.08%and 2.36% respectively;and(3) the average safety factors of monitoring points on the monitoring sections of SFRC and SBHFRC secondary lining structures are increased by 38.73% and 50.04% respectively.