热融湖的侧向热侵蚀对周围冻土工程产生较大影响。在柱坐标下,运用带相变的数值热传导模型,预测了热融湖影响下冻土路基的地温场发展状况和可能造成的工程病害。预测结果表明:在不考虑湖岸坍塌后退、面积扩大的情况下,热融湖对冻土路基的热影响主要受湖底年平均温度和湖边到路基的距离两个因子的影响。湖底年平均温度越高,对路基的热影响越严重;湖边到路基的距离越近,对路基的热影响亦越严重。突出的表现在坡脚、路基中心平均地温升高和融化夹层在水平、竖直方向的发展。如果考虑热融湖的湖岸坍塌后退,实际增温要比模拟的结果更明显,影响更严重。
The lateral thermal erosion of thaw lake may damage the stabilization of the nearby engineering. This study discussed the lateral transfer heat mechanism of the thaw lake, and a heat transfer model with phase change was used to predicte the temperature regime changes beneath the frozen soil roadbed and possible subgrade defects under the influence of the thaw lake. The results show that the thermal erosion of the thaw lake to permafrost roadbed is mainly affected by the annual average lake-bottom temperature and the distance from the roadbed to lake-edge. Supposing the lake area is constant, the impact of the thaw lake with a higher annual average lake-bottom temperature on the permafrost roadbed is more serious than that with a lower annual average lake-bottom temperature, and also is more obvious with the distance decrease from the roadbed to the lake-edge. These impacts mainly include the gradually warming ground temperature and the expanding tatik area beneath the roadbed. However, the most thaw lakes have been experiencing a process of area expansion. If this factor is considered, the actual increase of ground temperature is higher than the forecast one, and the damage is more serious.