季冻区隧道离壁式波纹钢板保温套衬及其保温效果研究

Study of Thermal Insulation Effects of Off-wall Corrugated Steel Plate LinerApplied in Tunnels in the Seasonally Frozen Region

为防治季冻区隧道中频繁出现的冻害问题,提出一种新型离壁式波纹钢板保温套衬,该套衬具有施工简便、防水性能可靠、防止混凝土掉块、提高聚氨酯使用寿命等优势,采用数值仿真对季冻区施作离壁式波纹钢板保温套衬隧道的温度场及其保温效果进行研究。结果表明:季冻区隧道施作新型离壁式波纹钢板保温套衬后,阻隔了寒冷空气对衬砌结构的影响,围岩正温区范围增大,隧道冻结线由距衬砌0.48 m围岩处前移至保温套衬,有效防止了季冻区隧道冻害的发生;季冻区隧道贴壁式聚氨酯保温层的保温效果为89.90%~96.43%,新型离壁式波纹钢板保温套衬的保温效果为101.94%~107.14%,离壁式波纹钢板保温套衬的保温效果要优于贴壁式聚氨酯保温层。

In order to prevent and control frozen damage that frequently occurs in tunnels in the seasonably frozen re⁃gion,a new thermal insulation liner composed of off-wall corrugated steel plates is developed,which is characterized by easy construction,reliable waterproof performance,resistance to concrete chipping,an increase in the service life of polyurethane and so on.Numerical simulation is performed to study the temperature field of the tunnels installed with thermal insulation liner composed of off-wall corrugated steel plates in the seasonably frozen region and its thermal insulation effect.The results show that the installation of the new thermal insulation liner composed of offwall corrugated steel plates in tunnels in the seasonably frozen region can prevent the impact of cold air on the lining structure,the area of surrounding rocks with positive temperature is increased,and the tunnel frost line moves for⁃ward from the surrounding rock position at 0.48 m away from the lining to the thermal insulation liner,effectively preventing the occurrence of frozen damage of tunnels in the seasonably frozen region;the thermal insulation effect of wall-mounted polyurethane thermal insulation layer of tunnels in the seasonably frozen region is 89.90%~96.43%,and the thermal insulation effect of new thermal insulation liner composed of off-wall corrugated steel plates is 101.94%~107.14%,with better thermal insulation effect than that of the former.