隧道二次衬砌欠厚整治技术探究

二次衬砌厚度不足病害直接降低隧道结构的可靠度。以某隧道为研究对象,对左线和右线二次衬砌厚度不足病害进行整治,从纵向里程变化和横断面不同位置两个方面对病害进行统计分析,采用结构计算软件对衬砌结构受力进行数值模拟以验证整治效果,以期能够为隧道二次衬砌厚度不足病害整治提供借鉴。取得结果如下:(1)在横断面位置上,拱顶处二次衬砌厚度不足病害最严重,且由拱顶经拱腰至拱脚,缺陷率依次减小;(2)在纵向里程上,左线拱顶处ZK125+400~ZK125+800、拱腰处ZK126+200~ZK127+200、ZK127+400~ZK128+200段,右线拱顶处K125+900~K127+800段,左拱腰处K125+400~K126+400,右拱腰处K126+600~K127+600段二次衬砌厚度不足病害最严重,建议加强衬砌质量检测;(3)得到二次衬砌厚度不足病害整治前后衬砌结构的内力及安全系数变化,整治后衬砌结构的承载力明显增强,拱腰和墙脚处安全系数显著增大,十分利于坑道侧壁的受力,证明整治措施有效。

Research on the Disease Treatment of Secondary Lining Thickness Lack in Tunnel

The disease of secondary lining thickness lack directly reduces the reliability of tunnel structure.Taking a certain tunnel as the research object,the secondary lining thickness lack at its left line and right line were treated,and statistical analysis on the diseases was made from two aspects of variation of longitudinal mileage,and different positions of cross section.The numerical analysis software was used to numerically simulate the stress of lining structure and to verify the performance of treatments,aiming to provide some references for treatment of tunnel lining disease.The main achievements were listed as follows:①On the cross-sectional position,the most serious disease of lining thickness lack is in the position of vault,and the defect rate decreases sequentially from the vault to hance,and then to arch foot.②In the longitudinal mileage,there are a lot of sections with more serious disease of secondary lining thickness lack,including the section of ZK125+400~ZK125+800 at vault of left line,ZK126+200~ZK127+200 and ZK127+400~ZK128+200 at hance of left line,as well as the section of K125+900~K127+800 at vault of right line,K125+400~K126+400 at left hance,K126+600~K127+600 of right hance.So it is suggested to strengthen the monitoring of tunnel lining quality.③The variation of internal force and safety factor of lining structure before and after its treatment on secondary lining thickness lack were grasped,showing that there is a significantly increase in the bearing capacity of lining and in the safety factor of the hance and the arch foot,which is beneficial to the force of tunnel side wall.It proves that the treatment is effective.