This page has only limited features, please log in for full access.
Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences 320 West Donggang Road, Lanzhou 730000, Gansu, China
Hydraulic conductivity of frozen soil is indispensable for describing water flow process in freezing soils. However, this conductivity is difficult to measure in the laboratory. So, the objective of this study is to propose a simple and smooth hydraulic conductivity model for saturated frozen soil based on the soil freezing characteristic curve (SFCC). Considering that the volume of pore water approximately represents the pore volume, the distribution of effective pore radii changed as a function of temperature was determined by combining the SFCC and the Gibbs–Thomson equation. Based on the distribution of effective pore radii, Hagen-Poiseuille equation, Darcy’s law, relative hydraulic conductivity and tortuosity, a simple and smooth hydraulic conductivity model for saturated frozen soil based on the SFCC was proposed. To illustrate the model performance, eight existing experimental cases were analyzed. The results showed that predictions considering the three different tortuosity formulations were in good agreement with the tested data; the results were worse when not considering the tortuosity and the results were best when considering the tortuosity τF=B/rb2. Moreover, the predictive modeling power was related to the tortuosity function. Furthermore, the model was further compared with the previous models, the results of which showed the better performance of the proposed model. The model is quite simple and timesaving to use when the SFCC and the saturated hydraulic conductivity are available. This result provides a new idea for developing the hydraulic conductivity model of saturated frozen soil.
Xiyan Zhang; Dongqing Li; Lei Chen; Feng Ming; Yuhang Liu. A new integral model for predicting the hydraulic conductivity of saturated frozen soil. Journal of Hydrology 2021, 603, 126838 .
AMA StyleXiyan Zhang, Dongqing Li, Lei Chen, Feng Ming, Yuhang Liu. A new integral model for predicting the hydraulic conductivity of saturated frozen soil. Journal of Hydrology. 2021; 603 ():126838.
Chicago/Turabian StyleXiyan Zhang; Dongqing Li; Lei Chen; Feng Ming; Yuhang Liu. 2021. "A new integral model for predicting the hydraulic conductivity of saturated frozen soil." Journal of Hydrology 603, no. : 126838.
Ice lens is the key factor which determines the frost heave in engineering construction in cold regions. At present, several theories have been proposed to describe the formation of ice lens. However, most of these theories analyzed the ice lens formation from a macroscopic view and ignored the influence of microscopic pore sizes and structures. Meanwhile, these theories lacked the support of measured data. To solve this problem, the microscopic crystallization stress was converted into the macro mean stress through the principle of statistics with the consideration of pore size distribution. The mean stress was treated as the driving force of the formation of ice lens and induced into the criterion of ice lens formation. The influence of pore structure and unfrozen water content on the mean stress was analyzed. The results indicate that the microcosmic crystallization pressure can be converted into the macro mean stress through the principle of statistics. Larger mean stress means the ice lens will be formed easier in the soil. The mean stress is positively correlated with initial water content. At the same temperature, an increase to both the initial water content and the number of pores can result in a larger mean stress. Under the same initial water content, mean stress increases with decreasing temperature. The result provides a theoretical basis for studying ice lens formation from the crystallization theory.
Yuhang Liu; Dongqing Li; Lei Chen; Feng Ming. Study on the Mechanical Criterion of Ice Lens Formation Based on Pore Size Distribution. Applied Sciences 2020, 10, 8981 .
AMA StyleYuhang Liu, Dongqing Li, Lei Chen, Feng Ming. Study on the Mechanical Criterion of Ice Lens Formation Based on Pore Size Distribution. Applied Sciences. 2020; 10 (24):8981.
Chicago/Turabian StyleYuhang Liu; Dongqing Li; Lei Chen; Feng Ming. 2020. "Study on the Mechanical Criterion of Ice Lens Formation Based on Pore Size Distribution." Applied Sciences 10, no. 24: 8981.
Engineering practices illustrate that the water phase change in soil causes severe damage to roads, canals, airport runways and other buildings. The freezing point is an important indicator to judge whether the soil is frozen or not. Up to now, the influence of salt on the freezing point is still not well described. To resolve this problem, a series of freezing point tests for saline soil were conducted in the laboratory. Based on the relationship between the freezing point and the water activity, a thermodynamic model considering the excess Gibbs energy was proposed for predicting the freezing point of saline soil by inducing the UNIQUAC (universal quasi-chemical) model. The experimental results show that the initial water content has little influence on the freezing point if the initial water content is higher than the critical water content, while the freezing point decreases with the decrease of the water content if the initial water content is lower than the critical water content. Moreover, it is found that the freezing point is related to the energy status of liquid water in saline soils and it decreases with the increase of the salt concentration. Moreover, the freezing point depression of saline soil is mainly caused by the decrease of water activity. Compared with the other two terms, the residual term, accounting for the molecular interactions, has an obvious influence on the water activity. This result is helpful for understanding how salt concentration affects the freezing point of saline soil and provides a reference for engineering construction in saline soil areas.
Feng Ming; Lei Chen; Dongqing Li; Chengcheng Du. Investigation into Freezing Point Depression in Soil Caused by NaCl Solution. Water 2020, 12, 2232 .
AMA StyleFeng Ming, Lei Chen, Dongqing Li, Chengcheng Du. Investigation into Freezing Point Depression in Soil Caused by NaCl Solution. Water. 2020; 12 (8):2232.
Chicago/Turabian StyleFeng Ming; Lei Chen; Dongqing Li; Chengcheng Du. 2020. "Investigation into Freezing Point Depression in Soil Caused by NaCl Solution." Water 12, no. 8: 2232.
Negative temperature curing is a very harmful factor for geopolymer mortar or concrete, which will decrease the strength and durability. The water in the geopolymer mixture may be frozen into ice, and the water content is a crucial factor. The purpose of this paper is to explore the influence of water content on the properties of alkali-activated binders mortar cured at −5 °C. Fly ash (FA) and ground granulated blast furnace slag (GGBFS) were used as binders. Three groups of experiments with different water content were carried out. The prepared samples were investigated through uniaxial compression strength test, Scanning electron microscopy (SEM), and X-ray diffraction (XRD) for the determination of their compressive strength, microstructural features, phase, and composition. The results indicated that, the compressive strength of samples basically maintained 25.78 MPa–27.10 MPa at an age of 28 days; for 90 days, the values reached 33.4 MPa–34.04 MPa. The results showed that lower water content is beneficial to improving the early strength of mortar at −5 °C curing condition, while it has little impact on long-term strength. These results may provide references for the design and construction of geopolymer concrete in cold regions.
Xiaobin Wei; Feng Ming; Dongqing Li; Lei Chen; Yuhang Liu. Influence of Water Content on Mechanical Strength and Microstructure of Alkali-Activated Fly Ash/GGBFS Mortars Cured at Cold and Polar Regions. Materials 2019, 13, 138 .
AMA StyleXiaobin Wei, Feng Ming, Dongqing Li, Lei Chen, Yuhang Liu. Influence of Water Content on Mechanical Strength and Microstructure of Alkali-Activated Fly Ash/GGBFS Mortars Cured at Cold and Polar Regions. Materials. 2019; 13 (1):138.
Chicago/Turabian StyleXiaobin Wei; Feng Ming; Dongqing Li; Lei Chen; Yuhang Liu. 2019. "Influence of Water Content on Mechanical Strength and Microstructure of Alkali-Activated Fly Ash/GGBFS Mortars Cured at Cold and Polar Regions." Materials 13, no. 1: 138.
In cold regions, hydraulic conductivity is a critical parameter for determining the water flow in frozen soil. Previous studies have shown that hydraulic conductivity hinges on the pore structure, which is often depicted as the pore size and porosity. However, these two parameters do not sufficiently represent the pore structure. To enhance the characterization ability of the pore structure, this study introduced fractal theory to investigate the influence of pore structure on hydraulic conductivity. In this study, the pores were conceptualized as a bundle of tortuous capillaries with different radii and the cumulative pore size distribution of the capillaries was considered to satisfy the fractal law. Using the Hagen-Poiseuille equation, a fractal capillary bundle model of hydraulic conductivity for saturated frozen soil was developed. The model validity was evaluated using experimental data and by comparison with previous models. The results showed that the model performed well for frozen soil. The model showed that hydraulic conductivity was related to the maximum pore size, pore size dimension, porosity and tortuosity. Of all these parameters, pore size played a key role in affecting hydraulic conductivity. The pore size dimension was found to decrease linearly with temperature, the maximum pore size decreased with temperature and the tortuosity increased with temperature. The model could be used to predict the hydraulic conductivity of frozen soil, revealing the mechanism of change in hydraulic conductivity with temperature. In addition, the pore size distribution was approximately estimated using the soil freezing curve, making this method could be an alternative to the mercury intrusion test, which has difficult maneuverability and high costs. Darcy’s law is valid in saturated frozen silt, clayed silt and clay, but may not be valid in saturated frozen sand and unsaturated frozen soil.
Lei Chen; Dongqing Li; Feng Ming; Xiangyang Shi; Xin Chen. A Fractal Model of Hydraulic Conductivity for Saturated Frozen Soil. Water 2019, 11, 369 .
AMA StyleLei Chen, Dongqing Li, Feng Ming, Xiangyang Shi, Xin Chen. A Fractal Model of Hydraulic Conductivity for Saturated Frozen Soil. Water. 2019; 11 (2):369.
Chicago/Turabian StyleLei Chen; Dongqing Li; Feng Ming; Xiangyang Shi; Xin Chen. 2019. "A Fractal Model of Hydraulic Conductivity for Saturated Frozen Soil." Water 11, no. 2: 369.
Feng Ming; Qi-Hao Yu; Dong-Qing Li. Investigation of embankment deformation mechanisms in permafrost regions. Transportation Geotechnics 2018, 16, 21 -28.
AMA StyleFeng Ming, Qi-Hao Yu, Dong-Qing Li. Investigation of embankment deformation mechanisms in permafrost regions. Transportation Geotechnics. 2018; 16 ():21-28.
Chicago/Turabian StyleFeng Ming; Qi-Hao Yu; Dong-Qing Li. 2018. "Investigation of embankment deformation mechanisms in permafrost regions." Transportation Geotechnics 16, no. : 21-28.
Concrete material has been a choice for the construction structures, even in the cold regions and saline zone. However, these environmental factors have critical damaging effect on the concrete characters. Consequently, this damage will decrease the servicing time of the concrete construction within this environment. In order to evaluate the durability of concrete, the behavior of concrete specimens under the sulfate solution corrosion attacks was studied in this presented work. Two groups of the specimens were immersed into the sulfate solutions with a concentration of 10% and 20%, respectively. The strength development of the specimens under different immersing time was studied. Based on Fick’s law, a steady diffusion equation for sulfate ions in concrete was presented, and the depth of penetration of the attacking sulfate ions was also determined. Based on the depth of penetration and the definition of damage, a damage model for concrete material is developed and a new equation (strength-time) describing the chemical corrosion concrete material is proposed. Results show that the suggested analytical methods can quantify the damage process of concrete under sulfate attack, and the power laws damage developing formula can be used to describe the damage development of the concrete construction subjected to chemical corrosion.
Feng Ming; Yousheng Deng; Dong-Qing Li. Mechanical and Durability Evaluation of Concrete with Sulfate Solution Corrosion. Advances in Materials Science and Engineering 2016, 2016, 1 -7.
AMA StyleFeng Ming, Yousheng Deng, Dong-Qing Li. Mechanical and Durability Evaluation of Concrete with Sulfate Solution Corrosion. Advances in Materials Science and Engineering. 2016; 2016 ():1-7.
Chicago/Turabian StyleFeng Ming; Yousheng Deng; Dong-Qing Li. 2016. "Mechanical and Durability Evaluation of Concrete with Sulfate Solution Corrosion." Advances in Materials Science and Engineering 2016, no. : 1-7.
According to the mixture theory and the principle of effective stress, acoustic wave equation of three-phased frozen soil was established. Through academic discussion and exponential analysis, it is obtained that the wave velocity is influenced by the soil types, ice content and water content, and decreases with an increase of water content. In order to validate the correctness of theoretical model tested the ultrasonic P-wave velocity of silty clay, silt and sand under the condition of different initial water contents and negative temperatures. Result shows that, the change of temperature causes the unfrozen water content changed and consequently causes the variation of P-wave velocity. P-wave velocity decreases with an increase of unfrozen water content and there is a good linear relation between them.
Li Dongqing; Huang Xing; Ming Feng; Zhang Yu. The Impact of Unfrozen Water Content on Ultrasonic Wave Velocity in Frozen Soils. Procedia Engineering 2016, 143, 1210 -1217.
AMA StyleLi Dongqing, Huang Xing, Ming Feng, Zhang Yu. The Impact of Unfrozen Water Content on Ultrasonic Wave Velocity in Frozen Soils. Procedia Engineering. 2016; 143 ():1210-1217.
Chicago/Turabian StyleLi Dongqing; Huang Xing; Ming Feng; Zhang Yu. 2016. "The Impact of Unfrozen Water Content on Ultrasonic Wave Velocity in Frozen Soils." Procedia Engineering 143, no. : 1210-1217.
Frost heave is attributed to water migration to the freezing front and the ice lens develops. Therefore, evaluation of frost heave requires the determination of the water migration in the freezing process. In order to predict the water migration in freezing soil, a water migration model which introduced the concept of migration potential (MP) was presented. This model presents a new approach for describing the water migration in freezing soils, in which the determination of the permeability coefficient in the frozen fringe and unfrozen zone was avoided. To verify the correctness of the proposed model, a series of unidirectional freezing experiments were conducted. Results show that small amount of water is intake to the soil due to the fast freezing rate, and that once the freezing rate becomes slow, the total amount of water intake is approximately increased with elapsed time. The water intake flux always changing with the elapsed time. As a result, the migration potential is a function of elapsed time. Finally, it is demonstrated that the predicted water intake flux is similar to the measured ones.
Feng Ming; Dong-Qing Li. A model of migration potential for moisture migration during soil freezing. Cold Regions Science and Technology 2016, 124, 87 -94.
AMA StyleFeng Ming, Dong-Qing Li. A model of migration potential for moisture migration during soil freezing. Cold Regions Science and Technology. 2016; 124 ():87-94.
Chicago/Turabian StyleFeng Ming; Dong-Qing Li. 2016. "A model of migration potential for moisture migration during soil freezing." Cold Regions Science and Technology 124, no. : 87-94.
For the construction in cold regions, frost heave and thaw settlement are the two factors which must be taken care of. Considered that a saturated soil column was subjected to an overburden pressure to model the ice lens growing process. A typical process, which coupled water, heat, and stress that happened in a saturated freezing soil column, was simulated by the finite element software. We did the numerical simulation under the same conditions as the experiment tests and then compared the results from temperature, frost heave, frozen structure, water content, and water intake. Result shows that the simulation results match well with the experimental results, and the correctness of the mathematical model is validated. On that basis, frost heave amount under different conditions by changing the temperature boundary and loading boundary is obtained. The frost heave has an optimum temperature gradient. Under the optimum value, the frost heave amount increases with increasing temperature gradient. Above the optimum value, frost heave decreases with increasing temperature gradient. Increasing the overburden pressure, frost heave amount always decreases. These results can provide references for the constrictions in cold regions.
Feng Ming; Dong-Qing Li. Experimental and Theoretical Investigations on Frost Heave in Porous Media. Mathematical Problems in Engineering 2015, 2015, 1 -9.
AMA StyleFeng Ming, Dong-Qing Li. Experimental and Theoretical Investigations on Frost Heave in Porous Media. Mathematical Problems in Engineering. 2015; 2015 ():1-9.
Chicago/Turabian StyleFeng Ming; Dong-Qing Li. 2015. "Experimental and Theoretical Investigations on Frost Heave in Porous Media." Mathematical Problems in Engineering 2015, no. : 1-9.
The consolidation of frozen soil is a coupled action of temperature and deformation. Using moving boundary method and taking the void ratio as a variable, the large strain thaw consolidation mathematical model is built according to Gibson’s large strain consolidation theory and thermal conductivity equation with consideration of phase change. In order to verify the model, a simple example is simulated by FEM software. The result shows that the consolidation range and consolidation rate are decided by the temperature boundary; the change of void and deformation are influenced by pore pressure dissipation and the thaw process in permafrost are delayed by consolidation process.
Feng Ming; Dong Qing Li; Kun Zhang. Theoretical Study on Thaw Settlement of Saturated Frozen Soil. Applied Mechanics and Materials 2012, 204-208, 155 -162.
AMA StyleFeng Ming, Dong Qing Li, Kun Zhang. Theoretical Study on Thaw Settlement of Saturated Frozen Soil. Applied Mechanics and Materials. 2012; 204-208 ():155-162.
Chicago/Turabian StyleFeng Ming; Dong Qing Li; Kun Zhang. 2012. "Theoretical Study on Thaw Settlement of Saturated Frozen Soil." Applied Mechanics and Materials 204-208, no. : 155-162.