隧道洞口段二衬病害评价分析及处治技术

张龙生¹，翁贤杰¹，熊小华¹，刘军²

1.江西交通咨询有限公司，江西 南昌  330008；

2.江西省交通投资集团有限责任公司，江西 南昌  330008

摘要：为治理隧道洞口段二衬病害，以某隧道进洞口段二衬开裂病害实例，从二衬裂缝分布、衬砌厚度、钢筋间距、仰拱回填等方面分析衬砌病害特征，采用荷载结构法通过数值计算获得典型病害断面的弯矩、轴力、剪力和安全系数，评估隧道结构安全状态。研究表明：S0型和S5型衬砌最小安全系数均低于规范要求，运营安全风险较高。针对二衬病害提出了围岩注浆加固、二衬粘贴钢板加固、明洞段拆除重建、过程动态监测为核心的系统处治技术。在隧道洞口段二衬病害处治过程中，累计拱顶沉降、收敛、裂缝发展和边坡位移分别为3.99、2.73、0.82、8.17 mm，变形速率分别为0.069、0.048、0.014、0.143 mm/d，均小于规范规定的监测项目控制标准，证明隧道洞口段二衬病害系统处治系统技术有效，可为类似病害处治提供参考。

关键词：二衬病害；隧道洞口段；荷载结构法；数值分析；处治技术

Analysis and treatment technology of the secondary lining diseases in the tunnel entrance

ZHANG Longsheng¹, WENG Xianjie¹, XIONG Xiaohua¹, LIU Jun²

1.Jiangxi Transport Consultation Company, Nanchang 330008, China;

2.Jiangxi Provincial Communications Investment Group Co., Ltd., Nanchang 330008, China

Abstract:To solve the diseases of secondary lining, combined with an practical cracking diseases of secondary lining at the tunnel entrance, the characteristics of the lining diseases are explored from the distribution of the cracks in the secondary lining, the thickness of the lining, the spacing of steel bars, and invert backfill, etc. The load structure method is used to obtain the bending moment, axial force, shear force and safety factor of the typical diseased section through numerical calculation, and the safety state of the tunnel structure is evaluated. The results show that the minimum safety factors of S0 and S5 linings are lower than the standard requirements, and the operational safety risks are high. Aiming at the secondary lining diseases, the systematic treatment technology with grouting reinforcement of surrounding rock, bonding steel plate reinforcement of secondary lining, demolition and reconstruction of open hole section and dynamic monitoring of process are put forward. In the treatment process of secondary lining diseases in tunnel portal section, the cumulative vault settlement, convergence, crack development and slope displacement are 3.99, 2.73, 0.82 and 8.17 mm, respectively, and the deformation rates are 0.069, 0.048, 0.014 and 0.143 mm/d, which are all less than the monitoring project control standards that proves the effectiveness of the secondary lining disease treatment system technology in tunnel portal section, and can provide reference for the treatment of similar diseases.

Keywords:secondary lining disease; tunnel entrance section; load structure method; numerical analysis; treatment technology