一、我国季节性冻土地带渠系水工建筑物的冻害情况凡温度为负温或零温,并且含有冰的各种土称为冻土。冬季冻结,夏季全部融化的土层为季节冻土;冬季冻结,一、两年内不融化的土层为隔年冻土;冻结状态持续三年或三年以上的土层为多年冻土。地球上多年冻土地区占陆地面积的26％,季节冻土地区更遍及各大 First, China’s seasonal frozen trough canal hydraulic structure of frozen buildings where the temperature is negative temperature or zero temperature, and contains a variety of ice called frozen soil. Frozen in winter, the summer all melts in the soil is seasonal frozen soil; winter frozen, one or two years does not melt soil every year permafrost; frozen state for three or more years of soil permafrost. Permafrost on Earth occupies 26% of the land area, and seasonal frozen soil areas are more widespread