市政冻结技术的应用与展望

Application and Prospect of Freezing Technology in Municipal Engineering

由于市政工程周边环境较为复杂,富水地层中降水法受到限制,故常采用人工冻结法加固土体。介绍市政冻结技术的发展历程、应用现状及关键技术问题,总结出按强度指标确定的冻结壁厚度计算公式;研发出保压平衡钻进新工艺,解决钻进过程中冻结管钻不进、断裂等问题;研发出PVC管盐水高效输送技术,输送冷量的散失量仅为同条件钢管的37.83%;对冻融环境效应及工程控制对策给出典型冻结案例,分析市政冻结技术发展存在的问题,并对今后的发展做了展望。

In general, the surrounding environment of municipal engineering is more complex, and the dewatering method is restricted in water-rich strata, so the artificial freezing method is used to strengthen the soil mass. In this paper, firstly, the development history, application status and key technical problems of the freezing technology in municipal Engineering were introduced, and the calcu- lation formula of frozen wall thickness based on the strength index was summarized.Secondly,the new drilling technology under the condition of pressure maintaining balance was developed,it can solve the problems that freezing tube can not be drilled into the stratum and fractures.Thirdly,the high efficien- cy transportation technology of saline water in PVC tube was developed,and the cold energy loss was only 37.83% of steel tube in the same condition. Fourthly,a typical freezing case of freezing-thawing environment effect and engineering control countermeasures was given, the problems existing in the development of freezing technology in municipal engineering were analyzed, and the development of the technology in the future was prospected.