Abstract: Significant climatic warming is in progress and causes degradation of permafrost and stability of superstructures. Especially under the more complex climate, frequently ultra weather and climate, the progress of bearing capacity in frozen ground is becoming more complex. taking a single pile in representative humid permafrost in Qinghai-Tibet plateau for example, considering the pile exposed in the air absorbs solar radiation, permafrost phase-change, natural air convection and global warming, the sensitivity of pile vertical bearing capacity to short-term climatic anomaly in permafrost regions is analyzed using finite element method. The numerical results show that the pile bearing capacity become lower under the short-term warmer climate because the decrease of adfreeze strength between pile and frozen ground, and no change of adfreeze area. The decrease influence is not fade away in the next years. The warmer climatic make the more decrease of bearing capacity. Under the colder climatic alternates with warmer climate, the pile bearing capacity is changed with outer air temperature, and regain normal after the climaticanomaly.

Key words: permafrost, pile foundation, beating capacity, climatic anomaly, response