加热限位管与自然解冻对冻土温度场影响的对比分析

Comparative Analysis of Influence of Heating Limit Tube and Natural Thawing on Frozen Soil Temperature Field

为解决人工冻结技术产生冻胀融沉所引发不良后果的问题,可设置加热限位管来达到控制冻胀融沉的目的。运用有限元软件研究了设置加热限位管与自然解冻对冻土温度场发展的影响规律,主要结论:无需加热时,间距800 mm单排冻结管在冻结50天时冻土厚度可达2.4 m;当限位管循环5℃热盐水之后,各点温度都有明显上升,离限位管越近温度受影响越大,随着时间的推移,各点温度趋于稳定,最终冻土厚度约1.4 m;而自然解冻工况下冻土帷幕最终厚度约1.2 m,整个冻土帷幕温度趋于一致、强度变得均匀,单从最终形成的冻土帷幕来看,自然解冻是最好选择。

To solve adverse consequence from frost heaving and thaw collapsing by artificial freezing technology,it can be set up to heating limit tubes to achieve the purpose of controlling forst heaving and thaw collapsing. The finite element software is adopted to research the influence rule of heating limit tube and natural thawing on the frozen soil temperature field. The results show that when heating is not needed,the single row freezing pipe with spacing of 800 mm can reach the thickness of 2. 4 m after 50 days＇ freezing. When the limit tube is filled with hot saline of 5 ℃,the temperature at all points is obviously increased. The temperature near the limit tube is greatly influenced. As time goes on,the temperature at all points is gradually stable and the final thickness of frozen soil is about 1. 4 m. However,by natural thawing,the final thickness of frozen soil curtain is about 1. 2 m and the temperature of frozen soil curtain is consistent,the strength is even.Just from the frozen soil curtain formed,the natural thawing is the best choice.