碩士 / 國立雲林科技大學 / 營建工程系 / 106 / The purposes of artificial ground freezing (AGF) technique in engineering applications are to form frozen zones in the ground with high strength and low permeability. The development of frozen soil is affected by several factors including the heat-carrying capability of freezing system, the seepage flow of groundwater, and the temperature of the ground, which might cause an incomplete frozen zone and a delay on the engineering project. The disadvantages due to the above factors could be prevented or improved through different kinds of freezing system, the temperature or flow rate of freezing fluid, spacing and arrangement of freezing pipes, etc. The freezing system can be air-cooling or water-cooling, Water-cooling system is generally superior to the air-cooling and is often used in the job site. In practice, the time and extent of joining individual zones into a unified frozen area are of concerned. In accordance, the spacing-diameter ratio of freezing pipes, and the heat-carrying capacity of freezer would become primarily important to the development of frozen soil.
In this study, the AGF model testing is conducted to investigate the effect of the spacing-diameter ratio of freezing pipes and the heat-carrying capacity of brine on the frozen soil development with or without seepage flow. Heat flux plates are installed in the model to measure the heat flow during the freezing tests. Results indicate the increase in spacing-diameter ratio of freezing pipes from 5 to 9 would enlarge the extent of frozen soils, while the time of joining the individual zones into a unified frozen area would be longer. Results also show the heat-carrying capacity can be adjusted by the temperature and flow of the brine, where the brine temperature appear to be the key factor. The brine flow rate would affect the growth of frozen area, but not the main one, and a limiting flow rate would appear existing that restrains the extent of the freezing. Through the measurements of heat flux plates, the heat flow in soil during the freezing process could be observed and details and the mechanism of freezing are therefore better understood.
| Identifer | oai:union.ndltd.org:TW/106YUNT0582030 |
| Date | January 2018 |
| Creators | LIU,BO-YOU, 劉柏佑 |
| Contributors | CHANG,MU-HSIUNG, 張睦雄 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 350 |
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