高原寒区水井及供水管路防冻与表层冻土开挖关键技术研究

Study on key techniques of freezing prevention and excavation of surface frozen soil for wells and water supply pipelines in plateau cold regions

高原(海拔3800~5500 m)高寒(-40℃)地区冬季漫长而寒冷,年均无霜期仅3个月左右,高寒缺氧且降水量少,冻土区分布广泛,高原寒区供水工程建设存在冻土层井水和供水管路极易冻结、表层冻土层开挖施工极为困难等一系列难题。结合工程建设实践经验,研究建立“注气扰动”井水防冻、“管路排空”供水管路不冻和冻土层开挖“冲击破碎抓斗”等3项关键技术。

In the plateau(altitude 3800~5500 m)and high cold(-40℃)regions,winter is long and cold,and the annual average frost-free period is only 3 months.Because of the high cold,sparse oxygen and low precipitation,the frozen soil area distributes widely.The construction of water supply engineering in plateau cold regions are faced with a series of difficult problems,such as quickly froze up of well water and water supply pipeline in frozen soil layer,difficult excavation of foundation in surface frozen soil layer,etc.Based on the experience of practice,three techniques are studied,includes“Air injection disturbance”freezing prevention of well water,“Pipe emptying”non-freezing of water supply pipeline,and“Impact crushing grab”in frozen soil excavation.