寒区隧道衬砌温度场及应力场变化规律研究

Study on the Variation Law of Temperature Field and Stress Field of Tunnel Lining in Cold Area

为了研究保温隔热层在冬季的保温效果,选择寒区隧道为研究对象,通过对比隧道是否铺设保温层来进行数值模拟,分析在多年重复温度荷载下温度场的分布,结果表明:在隧道铺设保温层后,能有效减少围岩的冻结深度,减缓围岩的冻融循环,隧道的使用寿命明显延长.在隧道洞口附近由于受到洞口及洞内气温影响,铺设的保温层在一定年限后不能有效保证围岩温度,无法完全阻止围岩内的冻胀发生.隧道在最大冻深时,衬砌最大压应力出现在仰拱和边墙汇交处,最大拉应力出现在仰拱处,且相较自重应力场,最大压应力变小,最大拉应力变大,对寒区隧道运营及维护具有一定的参考价值.

In order to study the thermal insulation effect of the thermal insulation layer in winter,the cold zone tunnel was selected as the research object.The numerical simulation was carried out by comparing whether the tunnel was laid with insulation layer.The distribution of temperature field under repeated temperature load was analyzed.The results showed that:the tunnel was laid.After the insulation layer,it can effectively reduce the freezing depth of the surrounding rock,slow down the freezing and thawing cycle of the surrounding rock,and the service life of the tunnel is obviously prolonged.In the vicinity of the tunnel entrance,due to the influence of the temperature in the hole and the hole,the insulation layer laid cannot effectively guarantee the surrounding rock temperature after a certain period of time,and cannot completely prevent the frost heave in the surrounding rock.When the tunnel is at maximum freezing depth,the maximum compressive stress of the lining appears at the intersection of the inverting arch and the side wall.The maximum tensile stress appears at the inverting arch,and the maximum compressive stress becomes smaller and the maximum tensile stress becomes larger than the self-heavy stress field.It has certain reference value for the operation and maintenance of cold zone tunnels.