藏西北革吉县雄巴乡场镇冻土灾害特征及防治措施
Characteristics and preventive measures of permafrost disasters in Xiongba town of Geji County in northwestern Tibet
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摘要: 近年来,藏西北革吉县雄巴乡场镇内的冻土灾害日趋严重,研究该区冻土灾害的特征、成因及危害,对制定相应的防灾减灾政策具有重要意义。从基本特征、成因条件、风险性及防治措施等方面对雄巴乡场镇的冻土灾害开展了综合研究,认为加剧该区冻土灾害的主要原因是全球气候变暖导致的降雨量增加和气温升高,使场镇内透水性差、不均匀分布的土体含水率增加,从而加剧了土体的冻胀冻融。冻胀冻融带来的破坏表现为房屋倒塌、地面裂缝、房屋墙体开裂以及地面不均匀沉降等。冻土灾害破坏强度可能随着气候变暖而进一步加剧,建议采取“导流+防洪+排水+工程建设”的综合防治措施,减少冻土灾害的破坏影响。研究成果可为今后雄巴乡场镇冻土灾害的成灾机制研究和重大冻土工程建设的防灾减灾提供科学的决策依据。Abstract: The permafrost disaster in the Xiongba town of Geji County has been aggravated in recent years. Investigating the characteristics, origins and hazards of permafrost disasters is of great significance to formulate corresponding disaster prevention and mitigation policies. The authors in this paper have comprehensively analyzed the permafrost disaster in Xiongba town by basic characteristics, causes, development trends and prevention mea-sures. The main cause of aggravating permafrost disasters is the increase of rainfall and temperature caused by the global warming. The frost heaving and freeze-thawing effect of the soil are aggravated by the increasing moisture content of the soil with poor permeability and uneven distribution. The damage caused by the frost heaving and freeze-thawing effect are in form of house collapse, ground cracks, house wall cracks and uneven ground settlement, and the disruptive strength increased with the climate warming. The comprehensive control measures of diversion + flood control + drainage + engineering construction were put forward to reduce the damage of permafrost disaster. This research could provide scientific decision-making and basis for formation mechanism of permafrost disaster and prevention and control measures of major permafrost engineering construction in Xiongba town.