Study of Frozen Soil Environment Relating to Engineering Activities
WU Qing-bai 1, ZHU Yuan-lin2, SHI Bin1 (1.Department of Earth Science, Nanjing University, Nanjing Jiansu 210093, China; 2.State Key Laboratory of Frozen Soil Engineering, CAREERI, CAS, Lanzhou Gansu 730000, China)
Frozen soilclosely relates to human activities and environment. Engineeringactivities may change frozen soil and ecological environment, freezing-thawing action and engineering stability. Therefore, studying theinfluence of engineering activities on frozen soil environment becomes an importance subject. Studying frozen soil environment can be divided into four aspects: 1) The change of frozen soil environment relating to natural factors; 2) The relationships between permafrost and ecological environment in cold regions; 3) The interaction between engineering and frozen soil environment; 4) The change of frozen soil environment under climate warming. Relationships between frozen soil environment and engineering activities are mainly reviewed in this paper. Engineeringactivity effects freezing-thawing action and results in permafrost environment losing its resumption capability. Therefore, assessing and predicating change of frozen soil environment relating toengineering activity become an important research content. The study of change in frozen soil environment relating to engineering activitiesmainly includes the following four aspects: 1) Assessment of frozen soil stability and sensitivity of ground surface; 2) Frozen soil environment and building stability; 3) Protection of frozen soil environment and reasonable utilization of land; 4) Ecological environment in frozen soil regions. The frozen soil stability is assessed by quantitative analyzing the permafrost stability, as well as proposing the thermal stability model based on permafrost energy change under natural condition and engineering activities. These quantitative assessment methods can be used to analyze and predicate the effect of engineering activities on frozen soil environment. The sensitivity of ground surface is studied by qualitative analyzing ground surface stability under the effect of engineering thermal disturbance, as well as proposing a sensibility classification based on the effect of engineering thermal disturbance. The qualitative analysis method can be used to assess the change of engineering geological condition. Studying the frozen soil environment and building stability mainly analyzes build stability after the change in thermal regime, seasonally thawing depth and freezing-thawing action, with ground ice thawed. In general, the engineering involves highway, railway, pipeline and hydrological installations. The linear building construction greatly influences frozen soil and ecological environment, thus, frozen soil environmental protection, reasonable utilization of land and ecological environment in frozen soil regions become new projects. Considering the influence of engineering thermal disturbance on frozen soil and ecological environment, as well as the destruction of engineering to vegetation, forest, and geological and frozen soil environment, the countermeasures of environmental protection are proposed, especially emphasizing the action of government supervision.