It is concluded that the freezing and thawing process and the thickness of active layers change with the changes of ground characteristics, affecting the permafrost further.

• 结果表明，由于工程活动改变了场地下垫面性质，造成了不同场地活动层冻融过程、活动层厚度等的差异，进而影响了多年冻土变化。