Study On Thermal Control Technology And The Long-term Effects Of Highway Subgrade In Permafrost Regions

The G214under construction is studied in this paper with its design data, geological condition and weather. Temperature fields of subgrade in permafrost area, where insulation material with different thickness is paved, are stimulated numerically based on finite element method. According to the results of stimulation, long term effect on wide subgrade with insulation material is evaluated. Followings are main conclusions of this paper:1. For unconstructed subgrades, the difference between annul maximum thawing depth of12m wide one and annul maximum thawing depth of24m wide one is relatively great, the annul maximum thawing depths of those subgrades mentioned above are3.40m and6.00m in30years operation, which means, thermal aggregation effect of subgrade in permafrost area, becomes obvious along with the increase of subgrade width, therefore, leads to increase of thawing depths.2. When0.1m thick EPS is paved in0.5m depth under subgrade surface, annual maximum thawing depths of subgrade centerline, road shoulder and base of slope increase along with the increase of subgrade surface width.0.1m thick EPS can’t maintain the upper limit of permafrost.3.In permafrost area, for subgrade where EPS is paved, thickness of EPS increases along with the increase of subgrade width. Reasonable thickness of EPS is0.1m when subgrade width is12m. To maintain the upper limit, thickness of EPS should be more than0.25m.4. For wide subgrade with3m height and24m width, insulation effect is better when insulation layer is paved in shallow depth, the recommended depth is0.50m-1.00m.