Abstract Roadways in permafrost regions are laid upon embankments because permafrost stratum is highly sensitive to the thermal disturbance at the ground surface. The south-facing slope of the embankment is exposed to longer insolation than the north-facing one annually, differing the solar absorption of the side slopes and thus developing differential settlement across the embankment. A simple, economical strategy is to reduce the solar absorptance of the southern side slope to a critical level such that the solar absorption of both slopes is equalized. However, it is unknown this critical absorptance of a specific embankment and it is also unknown if this critical absorptance can be achieved by using existing techniques. This study mimics the solar radiation falling on the side slopes of embankments with different configurations, and subsequently it estimates the solar absorption of the side slopes. We found that in sunny weather when the thermal asymmetry of an embankment is maximum, reducing the southern side-slope absorptance from 0.80 to 0.40 can eliminate the thermal asymmetry. By analyzing the solar absorptance of a rough surface such as a crushed-rock layer, we can ascertain that this critical absorptance can be achieved by coating the side slope with nonwhite high-reflective pigment.

中文翻译：

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调节太阳能吸收率以修复道路路堤的热不对称

摘要 由于多年冻土层对地表热扰动高度敏感，多年冻土地区的道路铺设在路堤上。路堤朝南的斜坡每年比朝北的斜坡暴露在更长的日照下，侧坡的太阳能吸收不同，从而在路堤上产生差异沉降。一个简单而经济的策略是将南侧斜坡的太阳能吸收率降低到一个临界水平，从而使两个斜坡的太阳能吸收率相等。然而，具体路堤的临界吸收率是未知的，并且该临界吸收率是否可以通过使用现有技术来实现也是未知的。这项研究模拟了落在不同配置路堤边坡上的太阳辐射，然后它估计边坡的太阳能吸收。我们发现，在晴天路堤热不对称性最大时，将南边坡吸光率从0.80降低到0.40可以消除热不对称性。通过分析粗糙表面（例如碎石层）的太阳能吸收率，我们可以确定通过在边坡上涂上非白色高反射颜料可以实现这一临界吸收率。