Abstract
The moisture and the temperature variation of shallow loess during the freeze‐thaw process have tremendous influences on the freeze‐thaw disease and agricultural development. The present paper, based on the field test of the temperature and water content of the shallow loess in the seasonal frozen region, probes into the variation of the temperature and moisture fields of shallow loess in the freeze‐thaw period. Field test shows that the daily variation of surface temperature reaches the maximum with the peak temperature appearing around 14:00, and the time when the peak temperature appears gradually postpones as the depth increases. Moreover, the daily variation of soil temperature decreases with the increase of temperature, and the variation can be ignored given the depth of more than 30 cm. In addition, there is an obvious variation of moisture content in shallow soil under the action of freeze‐thaw cycles. In this regard, the coupled calculation model is proposed in this paper to simulate the dynamic variation of temperature and moisture in shallow soil in Bin County located in Western China under natural conditions, compare the calculation value with the measurement value, and further verify the rationality of the numerical calculation method and parameter selection. Furthermore, the variation law of the maximum frozen depth with the air temperature is obtained through the simulation of extreme cold climate conditions.
Highlights
Most of the loess areas in China, in essence, belong to the seasonal frozen ground region, and the temperature and moisture fields vary with seasons under the influence of natural factors
In winter, the freezing action leads to the migration of moisture to the freezing layer and the increase of moisture content in shallow soil, which accounts for the frequent occurrences of engineering diseases, such as the slope, subgrade collapse, spalling, the frost heave, and thawing settlement of the Loess Plateau [1,2,3,4,5], and affects the agricultural development and the afforestation of mountains and rivers [6,7,8,9]
Of a large number of relevant studies, many scholars point out that the diseases are closely related to the variation of the temperature and moisture fields of shallow loess
Summary
Most of the loess areas in China, in essence, belong to the seasonal frozen ground region, and the temperature and moisture fields vary with seasons under the influence of natural factors. Most studies concerning the law of temperature and moisture under the freezing action focus on the indoor test with few conducted based on the field test In this respect, the present paper selects three typical sites in the Loess Plateau in Northern Shaanxi, China, to investigate the variation of temperature field and moisture field of shallow soil in the freeze-thaw cycle and further establish a numerical moisture-heat coupling calculation model for the simulation of natural conditions. Based on the comparison between measured value and numerical value, this paper verifies the rationality of the calculation model and parameter in an attempt to lay a solid foundation for the exploration of the mechanism of engineering freeze-thaw diseases in the seasonal frozen soil area
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
