论文部分内容阅读
为分析高寒大温差冻融环境对公路隧道衬砌结构长期服役性能的影响,采用现场测试方法得到了姜路岭隧道洞口温度变化规律,基于室内冻融循环试验拟合了冻融环境下衬砌混凝土力学性能劣化计算公式,应用荷载结构法建立了高寒冻融环境下衬砌结构服役性能的时空预测模型。研究结果表明:铺设厚度为5cm、导热系数为0.03 W·(m·℃)~(-1)的保温层后,姜路岭隧道1年内经历的等效室内冻融循环次数从8下降为0.32;无保温层且混凝土饱水条件下,5、10、15、20年后拱脚处截面安全系数相对于刚服役时分别降低了0.6%、23.7%、41.1%、69.8%,二次衬砌服役20年后安全系数已不能满足结构承载的要求;铺设厚度为5cm、导热系数为0.03 W·(m·℃)~(-1)的保温层后,二次衬砌服役100年后安全系数仍能够满足承载要求。可见冻融循环的剧烈程度对衬砌结构长期服役性能影响显著,保温层能有效改善混凝土的冻融环境。
In order to analyze the influence of freezing and thawing environment on the long-term service performance of highway tunnel lining structure, the temperature variation of tunnel entrance of Jianglingling tunnel was obtained by field test. The mechanical properties of lining concrete under freezing-thawing environment were fitted based on indoor freeze-thaw cycles The formula of spatio-temporal prediction of service performance of lining structure under freezing-thawing alpine environment is established by using load structure method. The results show that the average indoor freezing and thawing cycles experienced by Jianglingling Tunnel within one year have been reduced from 8 to 0.32 after the laying of the insulation with a thickness of 5cm and a thermal conductivity of 0.03 W · (m · ℃) -1. Insulation layer and concrete saturated water conditions, 5, 10, 15, 20 years after the cross-section of the safety factor at the arch with respect to just service reduced by 0.6%, 23.7%, 41.1%, 69.8%, 20 years of service of the secondary lining The safety factor can not meet the requirement of structural load. After laying insulation layer with thickness of 5cm and thermal conductivity of 0.03 W · (m · ℃) -1, the safety factor of 100% Claim. Shows that the severity of the freeze-thaw cycle significantly affect the long-term service performance lining structure, insulation can effectively improve the freeze-thaw environment of concrete.