Abstract: The expressway route selection should mainly consider the overall economic and social benefits and especially in case of mountainous areas, it can involve great difficulty and high engineering cost and often has to neglect the special conditions for some local sections. Chongqing Qijiang-Wansheng Expressway passes above the coalfield on the north wing of Nantong Coal Mine of Nantong Mining Company and covers and occupies a large amount of coal resource of the mine. Therefore, mining the coal under the expressway, making quantitative and qualitative research and analysis of the mining-caused damages such as subsidence, inclination, curvature, horizontal movement and horizontal deformation of the expressway by applying the scientific research achievement of the movement and deformation of the overlying layer after the coal mining, evaluating and judging the safety and putting forward safety measures have become new subjects of researchers for coal mining under building, water body and railway. In light of the features of the expressway in mountain areas and taking Qijiang-Wansheng Expressway as example, the effect of the underground coal mining on the expressway was systematically studied and the mining-caused damage evaluated. Preliminary discussion was made on the coal mining under the expressway in operation and the technical measures for the safety were proposed.

Key words: Under-expressway coal mining, assessment of mining-caused damage, safety measures