scholarly journals Experimental Investigation on Frost Heaving Force (FHF) Evolution in Preflawed Rocks Exposed to Cyclic Freeze-Thaw Conditions

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yu Wang ◽  
Tao Sun ◽  
Haonan Yang ◽  
Jinfeng Lin ◽  
Hao Liu
Keyword(s):  
Frost Heaving ◽  
Cycle Number ◽  
Recovery Stage ◽  
Water Ice ◽  
Freeze Thaw ◽  
Structural Deterioration ◽  
Steady Stage ◽  
Mesoscopic Structure ◽  
Evolution Characteristics ◽  
Peak Value

This work is aimed at investigating the structural deterioration and the frost heaving force evolution characteristics of flawed rocks using a self-developed frost heaving force (FHF) measurement system. Three kinds of preflawed rocks with different flaw geometry parameters were used to conduct the FHF measurement tests. The testing results reveal five distinguished stages from the frost heaving force evolution curve; they are the inoculation stage, explosive stage, decline to steady stage, recovery stage, and sudden drop stage. In addition, a secondary frost heaving phenomenon is found, and the secondary peak value is lower than the initial peak value. Moreover, the FHF decreases with increasing the F-T cycle number, and its decreasing rate becomes faster at a high F-T cycle. The frost heaving force is affected not only by flaw geometry but also by the lithology. For low-pore hard rock, damage propagates quickly after the occurrence of freeze-thaw damage. It is suggested that the mesoscopic structure of rock affects the water migration and water-ice phase transformation, and rock can be fractured by FHF in the preexisting flaws.

scholarly journals Experimental Evaluation of Multiple Frost Heaving Parameters for Preflawed Granite in Beizhan Iron Mining, Xinjiang, China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yu Wang ◽  
Dayu Long ◽  
Zulifeiya Rejuti ◽  
Huajian Wang
Keyword(s):  
Force Measurement ◽  
Frost Heaving ◽  
Migration Ability ◽  
Water Ice ◽  
Steady Stage ◽  
Mechanical Weathering ◽  
The Stability ◽  
Cement Strength ◽  
Force Measurement System ◽  
Rock Lithology

Ice-driven mechanical weathering in cold regions is considered a main factor impacting the stability of rock mass. In this work, the response surface method (RSM) was employed to evaluate and optimize the multiple frost heaving parameters to seek the maximum frost heaving force (FHF), in combination with experimental modeling based on a specially designed frost heaving force measurement system. Three kinds of rocks were prepared with parallel flaws in it having different flaw width, length, and cementation type, and these factors were used to fit an optimal response of the maximum FHF. The experimental results reveal five distinguished stages from the frost heaving force curve, and they are inoculation stage, explosive stage, decline to steady stage, recovery stage, and sudden drop stage. The sensitivity analysis reveals the influential order of the considered factors to peak FHF, which is the rock lithology, flaw width, flaw cement type, and flaw length. For low-porosity hard rock, increasing flaw width, flaw length, and flaw cement strength can improve the probability of frost heaving failure. It is suggested that rock lithology determines the water migration ability and influences the water-ice phase transformation a lot.

scholarly journals The Effects of Particle Gradation on Salinized Soil in Arid and Cold Regions

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 236
Author(s):  
Xuebang Huang ◽  
Zizhao Zhang ◽  
Ruihua Hao ◽  
Zezhou Guo
Keyword(s):  
Particle Size ◽  
Soil Samples ◽  
Frost Heaving ◽  
Particle Content ◽  
Cold Regions ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Salinized Soil ◽  
Size Grading

Particle size grading impacts salt-frost heaving and dissolution collapse events of salinized soil on northwestern China’s arid and cold region highways. However, the influencing mechanisms remain unclear and the impact of varying particle size grading needs further investigation. Hence, this study focused on these effects and the number of freeze–thaw cycles on the characteristic changes in highway salinized soil in arid and cold regions. Three soil columns with different gradations were prepared to explore the gradation and the number of freeze–thaw cycle affects on salinized soil’s salt-frost heaving and dissolution collapse characteristics. The multi-functional physical simulation platform conducted multiple freeze–thaw cyclic tests in the laboratory. Test results confirmed significant and conclusive effects of gradation and the number of freeze–thaw cycles on salinized soil’s salt-frost heaving and dissolution collapse behaviors. Poorly graded salinized soil with high coarse particle content caused repeated freeze and thaw engineering hazards, significantly affecting salinized soil’s displacement and deformation behaviors during freezing. Contrarily, an increased range of fine particles more easily involved the characteristics of salinized soil during thawing. Therefore, the fourth freeze–thaw cycle was a crucial time node. After four freeze–thaw cycles, the displacement and deformation of original salinized soil and B-grade salinized soil samples (poorly graded with high fine particle content) tended to be stable. In contrast, the displacement and deformation of A-grade salinized soil samples (poorly graded with high coarse particle content) increased the growth rate. The present research results contribute to in-depth knowledge of the effects of gradation and freeze–thaw cycles on the characteristics of salinized soil in northwestern China, providing excellent referenced data support for the prevention and control of highway salinized soil failures and other engineering projects in arid and cold regions of northwest China.

Freeze–thaw actuator and applications

2018 ◽  
Vol 29 (10) ◽  
pp. 2267-2276
Author(s):  
Niell Elvin ◽  
Alex Elvin
Keyword(s):  
Piezoelectric Element ◽  
Electrical Energy ◽  
Smart Material ◽  
Stored Energy ◽  
Water Ice ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Land Mass ◽  
Freeze Thaw Cycle ◽  
Self Powered

Significant portions of the earth’s land mass undergo annual freeze–thaw cycles, and although water is abundant and practically a free resource, the possibility of using the water–ice phase transition for smart material applications and actuators for machines has not been studied. This article details some of the characteristics of a freeze–thaw actuator, compares it to other smart material actuators, and presents three experimental demonstrations of its potential for engineering applications. The first application is the conversion of the freeze cycle into electrical energy by coupling the freeze–thaw actuator with a bistable piezoelectric element. The second application demonstrates the ability to store energy mechanically and keep a count of multiple freeze–thaw cycles. This stored energy can then be released after a preset number of freeze–thaw cycles. The third application demonstrates a self-powered mechanism that is capable of moving itself one body length per freeze–thaw cycle.

scholarly journals Research on the Pore Evolution of Sandstone in Cold Regions under Freeze-Thaw Weathering Cycles Based on NMR

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Zheng Pan ◽  
Keping Zhou ◽  
Rugao Gao ◽  
Zhen Jiang ◽  
Chun Yang ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Pore Structure ◽  
Western China ◽  
Cold Regions ◽  
Abrupt Decrease ◽  
Evolution Law ◽  
Red Sandstone ◽  
Freeze Thaw ◽  
Evolution Characteristics ◽  
Pore Evolution

The evolution of the rock pore structure is an important factor influencing rock mechanical properties in cold regions. To study the mesoscopic evolution law of the rock pore structure under freeze-thaw weathering cycles, a freeze-thaw weathering cycle experiment was performed on red sandstone from the cold region of western China with temperatures ranging from -20°C to +20°C. The porosity, T2 spectral distribution, and magnetic resonance imaging (MRI) characteristics of the red sandstone after 0, 20, 40, 60, 80, 100, and 120 freeze-thaw weathering cycles were measured by the nondestructive detection technique nuclear magnetic resonance (NMR). The results show that the porosity of sandstone decreases first and then increases with the increase of the freeze-thaw weathering cycles and reaches the minimum at 60 of freeze-thaw weathering cycles. The evolution characteristics of porosity can be divided into three stages, namely, the abrupt decrease in porosity, the slow decrease in porosity, and the steady increase in porosity. The evolution characteristics of the T2 spectrum distribution, movable fluid porosity (MFP), and MRI images in response to the freeze-thaw weathering process are positively correlated with the porosity. Analysis of the experimental data reveals that the decrease in the porosity of the red sandstone is mainly governed by mesopores, which is related to the water swelling phenomenon of montmorillonite. Hence, the pore connectivity decreases. As the number of freeze-thaw cycles increases, the effect of the hydrophysical reaction on the porosity gradually disappears, and the frost heaving effect caused by the water-ice phase transition gradually dominates the pore evolution law of red sandstone.

scholarly journals Fracture mechanism of rock collapse in the freeze-thaw zone of eastern Sichuan-Tibet Mountains under seasonal fluctuating combinations of water and heat

2021 ◽  
Author(s):  
Yong Wu ◽  
Xinpo Li ◽  
Lei Zhu
Keyword(s):  
Hydrostatic Pressure ◽  
Fracture Mechanics ◽  
Freezing Stress ◽  
Collapse Mechanism ◽  
Water Ice ◽  
Freeze Thaw ◽  
Different Seasons ◽  
Rock Collapse ◽  
Thaw Zone ◽  
Eastern Sichuan

Abstract In the freeze-thaw zone of eastern Sichuan-Tibet Mountains, the phases of water in cracks show strong seasonal variations, which significantly affect the stability of perilous rocks in mountains. However, few works have clearly addressed the role of water/ice in crack development from a fracture mechanics viewpoint to explain the seasonality of rock collapse. In this study, we built physical models from a fracture mechanics viewpoint to calculate water-freezing stress, hydrostatic pressure, and their combinations induced by water/ice in cracks, and show the crack propagation mechanism under temperature fluctuations in different seasons in mountainous regions. Based on the models, we calculate fracture conditions, simulate the crack process, and illustrate the rock collapse mechanism in different seasons by the extended finite element method. The results indicate that different phases of water, which induce stress under spatiotemporal fluctuations of temperature, determine the various propagation styles and influence what kind and when a collapse will occur. The collapse of fractured rocks in different seasons generally results from rock damage accumulation owing to the initiation, propagation, and connection of primary cracks under freezing stress or hydrostatic pressure or their different combinations.

scholarly journals A finite volume-based model for the hydrothermal behavior of soil under freeze–thaw cycles

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252680
Author(s):  
Tianfei Hu ◽  
Tengfei Wang
Keyword(s):  
Heat Transfer ◽  
Finite Volume ◽  
Fluid Transport ◽  
Numerical Solutions ◽  
Dynamic Equilibrium ◽  
Phase Changes ◽  
Freezing And Thawing ◽  
Water Ice ◽  
Freeze Thaw ◽  
Physics Model

Freeze–thaw cycles in soil are driven by water migration, phase transitions, and heat transfer, which themselves are closely coupled variables in the natural environment. To simulate this complex periglacial process at different time and length scales, a multi-physics model was established by solving sets of equations describing fluid flow and heat transfer, and a dynamic equilibrium equation for phase changes in moisture. This model considers the effects of water–ice phase changes on the hydraulic and thermal properties of soil and the effect of latent heat during phase transition. These equations were then discretized by using the finite volume method and solved using iteration. The open-source software OpenFOAM was used to generate computational code for simulation of coupled heat and fluid transport during freezing and thawing of soil. A set of laboratory freezing tests considering two thermal boundary conditions were carried out, of which the results were obtained to verify the proposed model. In general, the numerical solutions agree well with the measured data. A railway embankment problem, incorporating soil hydrothermal behavior in response to seasonal variations in surface temperature, was finally solved with the finite volume-based approach, indicating the algorithm’s robustness and flexibility.

scholarly journals Equation for the Degradation of Uniaxial Compression Stress of Concrete due to Freeze-Thaw Damage

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaolin Yang ◽  
Genhui Wang ◽  
Shiwu Gao ◽  
Min Song ◽  
Anqi Wang
Keyword(s):  
Concrete Strength ◽  
Damage Variable ◽  
Curved Surface ◽  
Large Temperature ◽  
Test Results ◽  
Stress Strain ◽  
Cycle Number ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

To study the freeze-thaw damage characteristics of concrete, the uniaxial compressive tests of concrete under different number of freeze-thaw cycles were conducted, and the damage variable of freeze-thaw was obtained. The test results showed that the stress was a function of strain and freeze-thaw damage variable, and it can describe the degradation of concrete strength. Meanwhile, the equation for the stress-strain curved surface about strain and freeze-thaw damage variable was also proposed in this paper. The derivative function of the stress-strain curved surface equation with respect to strain presented the change of elastic modulus with the increase of freeze-thaw cycle number. Equation proposed in this paper can be used for predicting the concrete lifetime effectively in cold and large temperature difference regions.

scholarly journals Durability Analysis of Sludge Solidified with Soda Residue Subjected to Dry-Wet and Freeze-Thaw Cycles

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jun He ◽  
Lei Zhang ◽  
Chi Zhang
Keyword(s):  
Hydration Reaction ◽  
X Ray Diffraction ◽  
Durability Test ◽  
Cycle Number ◽  
Freeze Thaw ◽  
Industrial Solid Waste ◽  
Filling Materials ◽  
Granulated Blast Furnace Slag ◽  
Durability Analysis ◽  
Furnace Slag

Soda residue (SR), ground-granulated blast-furnace slag (GGBS), and quicklime (QL) were employed for solidifying sewage sludge, which is a technique for sustainable development by transforming industrial solid waste and sludge into engineering fill material such as backfill material in mine or abandoned caverns. The durability of solidified sludge against dry-wet and freeze-thaw cycles was investigated by unconfined compressive strength (UCS), X-ray diffraction, scanning electron microscopy, and nuclear magnetic resonance tests. The results demonstrated that the SR-GGBS-QL solidified sludge had good dry-wet and freeze-thaw durability. In general, UCS increased at first, but then it decreased to some degree with the increase in dry-wet and freeze-thaw cycles. The cycle number for peak UCS depended on the durability test types and SR content. The UCS values after seven dry-wet cycles or ten freeze-thaw cycles were higher than the initial values before cycles. The main products detected in SR-GGBS-QL solidified sludge were ettringite, hydroaluminite, and calcium silicate hydrate (C-S-H). In addition, some pollutants such as copper, arsenic, and chromium were stabilized. The weakening effect on the microstructure of the solidified sludge occurred after dry-wet or freeze-thaw cycles. However, the hydration reaction continued with the increase of dry-wet and freeze-thaw cycles, leading to an increase in the amount of hydration products (especially C-S-H) and compact microstructure. These contributed to high UCS values and good dry-wet and freeze-thaw durability. The strength and failure strain of solidified sludge still met the requirement of filling materials after dry-wet or freeze-thaw cycles.

Research on Hydraulic Soil Slope Frost Heaving Damage Model Test

2012 ◽  
Vol 256-259 ◽  
pp. 422-426
Author(s):  
Hua Zhong ◽  
Xiu Fen Wang ◽  
Bin Zhang
Keyword(s):  
Model Test ◽  
Damage Model ◽  
Frozen Soil ◽  
Laboratory Model ◽  
Soil Slope ◽  
Frost Heaving ◽  
Freeze Thaw ◽  
Seasonal Frozen Soil ◽  
Water Conservancy Project ◽  
Water Conservancy

Frost heaving damage of water conservancy project is widespread. In order to research the failure problems of hydraulic soil slope in dark seasonal frozen soil region, laboratory model test is carried out combined with field test section practical situation, which is the prototype of this model test. It is researched that the rule of frost heave parameters variation and the damage of soil slope during freeze-thaw cycling. That offers theoretical basis and reference for construction of water conservancy project, which will mitigate the effect and damage of freeze-thaw on hydraulic soil slope stability.

Correlation Analysis on Frost Heaving Ratio of Subgrade Soil and Plasticity Index under Freeze-Thaw Cycles

2011 ◽  
Vol 255-260 ◽  
pp. 1171-1175 ◽  
Author(s):  
Han Bing Liu ◽  
Jing Wang ◽  
Chun Li Wu ◽  
Kai Feng
Keyword(s):  
Correlation Analysis ◽  
Closed System ◽  
Frozen Soil ◽  
Plasticity Index ◽  
Frost Heaving ◽  
Freeze Thaw ◽  
Subgrade Soils ◽  
Nonlinear Fitting ◽  
Subgrade Soil ◽  
The Relationship

Three kinds of subgrade soils with different plasticity index are selected from seasonally frozen soil region. Frost heaving ratio of volume and height was performed on the samples exposed to 0 to 8 times closed-system freeze-thaw cycles. The results show that concerning the same kind of soil, the frost heaving ratio increases with the number of freeze-thaw cycles; Frost heaving ratio increases with plasticity index under the same number of freeze-thaw cycles. Multiple nonlinear fitting is adopted for test data. The relationship between frost heaving ratio and plasticity index, freeze-thaw cycles is obtained and shows a good correlation. The relation can provide useful reference for subgrade design and construction in seasonally frozen soil region.

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