公路隧道衬砌多病害安全性分析

Safety Analysis of Multiple Diseases of Lining of Highway Tunnel

基于隧道衬砌检测数据结果,建立荷载-结构法有限元模型,分别对衬砌背后空洞、衬砌裂缝和衬砌欠厚多工况多部位组合计算分析,得出隧道衬砌多病害共存对衬砌各部位安全性影响的规律。研究结果表明衬砌拱顶裂缝比衬砌拱腰裂缝、其他位置裂缝更加危险,拱顶裂缝需采取必要措施处理,隧道设计和施工阶段,应着重对拱顶进行重点关注,以减少隧道运营期产生灾害的概率。Ⅲ级围岩二衬为素混凝土衬砌且衬砌多病害共存时,衬砌安全系数下降得最快;衬砌裂缝和衬砌欠厚对邻近的截面安全性影响较大,对较远的截面影响有限。各种隧道病害中,衬砌欠厚对衬砌安全性影响最大,背后空洞对衬砌安全性影响最小。Ⅲ〜Ⅴ级围岩中,Ⅲ级衬砌和Ⅴ级衬砌病害对衬砌安全性影响最大。

Based on the test data of tunnel lining,the finite element model of load structure method is established to calculate and analyze the cavity behind the lining,lining cracks and thinner thickness of lining under multiple working conditions and multiple parts.The influence of multiple diseases of tunnel lining on the safety of each part of lining is obtained.The results show that the cracks in the top of lining arch are more dangerous than those in the waist and other positions,and should be solved by necessary measures.During the tunnel design and construction,the vault should be paid more attention to reduce the probability of disasters.When the secondary lining of grade Ⅲ surrounding rock is plain concrete lining and multiple lining diseases coexist,the safety factor of lining decreases fastest.The lining crack and thinner thickness influence more on the safety of adjacent section and little on the far section.Among all kinds of tunnel diseases,the thinner thickness of lining has the greatest influence on the safety of lining,and the cavity behind the least.As for grade Ⅲ~Ⅴ surrounding rock,diseases of lining grade Ⅲ and grade Ⅴ have the greatest influence.