Frost heave and freezing processes of saturated rock with an open crack under different freezing conditions
- PDF / 2,439,446 Bytes
- 14 Pages / 595.276 x 785.197 pts Page_size
- 88 Downloads / 218 Views
RESEARCH ARTICLE
Frost heave and freezing processes of saturated rock with an open crack under different freezing conditions Zhitao LVa,b, Caichu XIAa,b* , Yuesong WANGa,b, Ziliang LINa,b a
Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China b
*
Corresponding author. E-mail: [email protected]
© Higher Education Press 2020
ABSTRACT Frost heave experiments on saturated sandstone and tuff with an open crack are conducted under uniform and unidirectional freezing conditions. Frost heave of crack in sandstone with high permeability is more significant under uniform freezing condition than that under unidirectional freezing condition. However, frost heave of crack in tuff with low permeability is more significant under unidirectional freezing condition. To illustrate the reasons for this phenomenon, a numerical model on the freezing processes of saturated rock with an open crack considering the latent heat of pore water and water in crack is proposed and confirmed to be reliable. Numerical results show that a frozen shell that blocks the migration of water in crack to rock develops first in the outer part of the rock before the freezing of water in crack under uniform freezing condition. However, the migration path of water in crack to the unfrozen rock under freezing front exists under unidirectional freezing condition. The freezing process and permeability of rock together determine the migration of water in crack and lead to the different frost heave modes of crack for various permeable rocks under different freezing conditions. The frost heave modes of crack in rock with low or high permeability are similar under uniform freezing condition because water migration is blocked by a frozen shell and is irrelevant to rock permeability. For high permeability rock, the frost heave of crack will be weakened due to water migration under unidirectional freezing condition; however, the frost heave of crack would be more significant for low permeability rock because water migration is blocked under unidirectional freezing condition. Therefore, the freezing condition and rock permeability determine the frost heave of rock with crack together, and this should be concerned in cold regions engineering applications. KEYWORDS
1
frost heave, rock with crack, freezing process, freezing condition, frost heave mode
Introduction
The frost heave of rock mass is a common problem that exists in geotechnical engineering applications, such as tunnels [1–3] or slopes [4] in cold regions and the storage of liquefied natural gas in underground rock chambers [5]. For example, the frost heave of the rock mass is considered a cause for the landslide disaster at the Toyohama Tunnel in Japan [6]. Numerous studies on the frost heave of rock have been conducted. If a saturated rock with a porosity n freezes in a closed system without water supply, then the potential volumetric freezing strain is 0
Data Loading...
