基于不同冻结试验模式分析控制冻胀规律

Base on Different Freezing Experiment Model Analying Heave-Preventing Mechanism

对冻结技术应用中冻胀控制这一重课题,通过试验比较了控制冻深的间歇冻结模式与传统连续冻结模式的冻胀量差异,试验结果表明:控制冻深的间歇冻结模式冻胀量为连续冻结模式的48.8%,其等效条件下的冻胀量约为连续冻结模式的71.2%,冻胀部分得到控制。针对该间歇冻结模式控制冻胀的规律,提出末透镜体层为冻胀控制的关键透镜体层。通过对试验的定性分析,指出控制冻深的间歇冻结模式在间歇段能够促使末透镜体分凝温度升高,形成速度减缓,继而出现停止形成的阶段,控制冻胀。分析指出控制冻深的间歇冻结模式是工程唯一可用的冻胀控制的冻结模式,且该模式较传统连续冻结模式更为经济。

For heave-preventing problem of freezing technique application, the amount of heave was compared between frozen-depth-controlled intermittent freezing mode and tranditional continuous freezing mode by experiments. The results showed that： the heave amount of intermittent mode was 48.8% that of continuous mode,and its equivalent heave amount was about 71.2% that of continuous mode,which meant frost heave was partially prevented. For heave-preventing mechanism of this intermittent mode, final ice lens was suggested as key ice lens. From qualitative analysis of experiments, heave-preventing menchanism for frozen-depth-controlled intermittent mode was indicated. Segragation temperature of final lens increased during intermittent phase for intermittent freezing mode slowed and even stopped the growth of final lens,and frost heave was thus controlled. Finally, frozen-depth-controlled intermittent freezing mode was indicated as the only applicable heave-preventing mode for engineering,and its more economic than traditional continuous freezing mode was also pointed.