Showing papers in "Cold Regions Science and Technology in 2018"

TL;DR: A series of triaxial compression, creep and stress relaxation tests at temperature of − 6°C were conducted on frozen loess, experienced different freeze-thaw numbers (0-12times), in order to study the thermal cycling effect in mechanical behaviors as discussed by the authors.

TL;DR: In this article, Liu et al. proposed a damage constitutive model under freeze-thaw and loading in order to evaluate the stability of a tunnel under coupled thermo-hydro-mechanical condition in cold regions.

TL;DR: In this article, a series of 140 freeze-thaw cycling tests are conducted on sandstone samples, and the results of T2 distribution and pore size changes are that the pore sizes of sandstones increase, especially that of micro-pores and macro-pore increase obviously after 140 freezethaw cycles.

TL;DR: In this article, specimens of densely compacted loess were exposed to different intensities of weathering processes under controlled laboratory environment to quantitatively assess their deterioration effects on geotechnical properties.

TL;DR: In this article, the effect of freeze-thaw cycles on the strength of expansive soils was investigated and a unified stress-strain relationship was formulated in a disturbed state concept (DSC) framework.

TL;DR: In this article, the effect of freeze-thaw cycles on the dynamic uniaxial compressive strength and energy distribution parameters including the specific energy absorbency rate (ES), energy reflectivity (ER) and energy transmitted rate (ET) are experimentally investigated.

TL;DR: In this article, a two-dimensional numerical model was developed to investigate how different design options, such as distance between the pipes, affect the efficiency of the HHP systems and the annual required energy for anti-icing and remaining hours of the slippery conditions on the road surface were numerically calculated using a finite element model.

TL;DR: In this article, the meso-structural characters for loess after freeze-thaw cycling were explored such as the equivalent diameter, the particle orientation, the degree of circularity and the ratio of porosity area.

TL;DR: In this article, the effects of fiber, cement, and freeze-thaw cycles on the cement-treated clay and fiber and cement stabilized clay were investigated and the dimension change ratio, stress-strain relationship curves, post-peak stress ratio, tangent modulus and unconfined compressive strength (UCS) were obtained and analyzed in terms of the number of freeze thaw cycles, cement and fiber contents.

TL;DR: In this paper, the deterioration of sandstone is investigated under rapid freeze-thaw (F-T) cycles, and the results showed that after applying F-T cycle specimens' mass, tensile strength and point load strength decrease at different extent while porosity increases.

TL;DR: In this article, the characteristics of the freezing-thawing deformation were analyzed, as well as the variation of the matric suction, based on the laboratory experiments, and the results showed that in each freeze−thaw cycle, the deformation can be divided into five stages, i.e. cold shrink, fast frost heave, slow deformation, thermal bulge and thaw settlement.

TL;DR: In this article, the deterioration mechanism and dynamic tensile properties of rock subjected to the effects of freeze-thaw cycles are investigated in Brazil disc granite specimens are treated by 0, 30, 60, 90, 120 and 120 freezing and thawing temperatures are −20°C and 20°C respectively.

TL;DR: In this article, a statistical model is proposed to predict the triaxial compressive strength of freeze-thawed transversely isotropic rocks based on the single discontinuity theory.

TL;DR: In this paper, the effect of fiber reinforcement on soil tensile property under freeze-thaw condition almost has not been investigated, but very limited information has been reported on its tensile behavior.

TL;DR: In this paper, a comparison of influences of freeze-thaw action on lime stabilized basalt and polypropylene fiber reinforced clay was investigated, and a linear correlation was observed between unconfined compressive strength and ultrasonic pulse velocity values.

TL;DR: In this paper, a triaxial creep test of frozen silty clay mixed with different contents of coarse grains was performed at 0.3 MPa confining pressure at − 10 °C.

TL;DR: In this article, a self-lubricating icephobic elastomer coating (SLIC) was realized by systematic optimization of silicone oil infusion levels within a robust, weather-resistant silicone elastic matrix for ultra-low ice adhesion, targeting high durability levels for a variety of applications operating in harsh icing environments.

TL;DR: In this article, the effects of F-T cycles and salt contents on the shear properties of saline soil in western Jilin Province of northeastern China, including stress-strain behavior, peak undrained shear strength (τu), resilient modulus (ER), cohesion (cu) and internal friction angle (φu), were investigated by conducting unconsolidated-undrained (UU) triaxial compression tests.

TL;DR: In this article, a resistivity model for testing the water content of frozen silty clay was proposed, which is based on the three-element electrical conduction model and four types of micro unit representing different unfrozen water contents.

TL;DR: In this article, a series of unconsolidated undrained triaxial compression tests of fine-grained soil subjected to freeze-thaw cycles were conducted and the strength properties of the weak soil reinforced by fibers were analyzed.

TL;DR: In this paper, the effect of ice severity on the power performance of wind turbines at natural icing environment was analyzed quantitatively in the image processing method, and it was found that the ice thickness on the blade increases rapidly from the root to the middle of the blade, and then slowly from the middle to the blade tip.

TL;DR: In this article, a series of freezing experiments has been conducted to investigate the frost heaving property of saturated rock under unidirectional freezing condition, in which the plane perpendicular to the freezing direction is the plane of transverse isotropy and the line parallel to the surface of the line along the radial direction of tunnels is the axis of transversal isotropy.

TL;DR: In this paper, a unified model for frost heave pressure in the rock with a penny-shaped fracture during freezing was proposed, in which the main influencing factors can be classified into four groups: 1) the mechanical properties of ice and rock (Ei, υi, Es and υs); 2) external loading conditions (q and λ); 3) shape characteristic of the fracture (η ); and 4) effective volume expansion coefficient (βe).

TL;DR: In this article, the authors examined 15 test sections along Lanzhou-Xinjiang high-speed railway (LXHR) and discussed the factors controlling the observed heave, and the development of frost heave in three subgrade layers (0-0.5, 0.5-1.5 and 1.7-m depth).

TL;DR: In this article, the deterioration mechanism of concrete subjected to freezing-thawing (F-T) actions was analyzed and the evolution and spatial distribution of internal pore structure were key factors in the damage mechanism and mechanical properties of concrete in the F-T environment.

TL;DR: In this paper, the authors investigated the effect of permafrost thawing and thaw bulb development around the pipe of the China-Russia Crude Oil Pipeline (CRCOP) and found that the mean monthly oil temperature ranged from 04 to 179°C and increased slowly with operation time increase.

TL;DR: In this paper, the F-T resistance of plain concrete, binary concrete, and ternary blended concrete mixtures made of ordinary portland cement (OPC), 5-fixed silica fume (SF), and various Class F FA contents up to 45% as replacement of cement by weight were evaluated.

TL;DR: In this article, the authors measured thermal conductivity at different gravimetric water/ice contents (GWC) in frozen and thawed permafrost, and calibrated a coupled heat and water transfer model, the CoupModel, to simulate permaffrost temperatures at two sites on the delta.

TL;DR: In this paper, the damage evolution equation of chemical freeze-thaw sandstone under load is established, and the damage correction coefficient is introduced to modify the total damage of chemical frozen-thawed sandstone.

TL;DR: In this paper, the effects of freeze-thaw on asphalt concrete and binder samples in the laboratory were investigated, and the results showed that the FT conditioning decreases the fatigue life of the pavement by 30.7, 33.3, 46.7 and 37.23%.