Journal of Cold Regions Engineering

Operating an effective winter road maintenance program is a necessity for cities that face severe winter seasons. Snowstorms leave roads in a slippery surface condition that disrupts traffic flows and compromises drivers’ safety. Decision-makers use a variety of tools to control snow and ice on the roads, which include applying anti-icing chemicals before snowstorms, applying deicing substances on fresh snow, and clearing snow off the roads using snowplows. However, the influence of these tools on improving the overall road surface conditions has not been investigated. In this study, a location-specific and event-based framework was utilized to understand the impact of the different weather variables as well as maintenance operations on the variability of the pavement friction coefficients during snowstorms in urban environments. Using multilinear regression and ordinary least squares, friction coefficient models were calibrated. The final model was found to be a good fit for the data (R² = 0.723). The model showed that the total precipitation during snowstorms, extremely low temperatures, and the potential for black ice formation worsen pavement friction significantly. On the other hand, plowing operations, the application of anti-icing chemicals before snowstorms, and frequent deicing operations all have a statistically significant impact on improving pavement friction. The model presented in this paper can be used to predict pavement friction on urban arterial and collector roads during snowstorms of different magnitudes, which could help the authorities in predicting the road surface conditions during forecasted snowstorms and deciding on the best course of action under these conditions.

The Lanolin 750 kV electrical transmission line traverses more than 102.86 km through seasonally frozen regions, causing many engineering problems for transmission tower foundations. In this work, physical models of reinforced concrete independent foundations in soils with different frost heave grades were used to simulate the frost heaving performance in seasonally frozen alpine regions. The test results were used to evaluate the tangential frost heaving force calculated based on different specifications. The results showed that the tangential frost heaving force and frozen depth increased with the temperature decrease. Moderately frost-susceptible soils also increased the tangential frost heaving force and frozen depth. Based on technical standards, the main differences between the calculated and the test values were the variable load component and effective frozen depth coefficients. Correcting the coefficient values resulted in a closer agreement between the test and the calculation results.

With the rapid development of China’s economy, the linear traffic infrastructure in the permafrost region has also developed rapidly. Many engineering problems in pile-supported bridges are caused by the freeze–thaw cycles and seismic activity on the roadbed when linear traffic passes over the frozen ground. Therefore, this study focused on the seismic response of a pile-supported bridge in frozen ground. A three-dimensional (3D) nonlinear finite-element (FE) model was established based on a pile-supported bridge, and various modeling techniques and methods were presented in detail. Specifically, the p−y curves in the frozen or unfrozen soil were calculated based on the experimental results from modeling the soil–pile interactions. Based on the computed results, the seismic response of a pile-supported bridge structure in the frozen ground was comprehensively investigated and compared with that in the unfrozen ground. The effect of the frozen ground on the seismic response of a bridge structure was systematically explored. The modeling technique and the derived insights could be significant for pile-supported bridges in frozen ground.

This study investigates the change in hysteretic properties of a lead–rubber bearing (LRB) exposed to low temperature. For this purpose, a full-scale LRB was conditioned at temperatures of −20°C, −10°C, 0°C, and 20°C for 24 hours and then subjected to displacement-controlled cyclic motions that correspond to various levels of shear strains. Tests were conducted with loading frequencies of 0.1 and 0.5 Hz. Recorded force–displacement curves were used to quantify the variation in isolator properties, namely, post-yield stiffness and characteristic strength (force intercept at zero displacement). Test results revealed that both post-yield stiffness and characteristic strength increase with decreasing temperature. The amount of increment becomes even larger with decreasing shear strain. Characteristic strength is found to be more prone to change in temperature compared with post-yield stiffness.

Owing to the scarcity of land resources, the rational development and utilization of frozen soil resources and solutions to frozen soil disasters have become extremely important. In this study, a time-domain reflectometer was used to monitor the temperature, moisture content, and electrical conductivity (EC) of sandy soil in the laboratory. Simultaneously, a nonlinear model of temperature, concentration, and EC was constructed to convert EC values into a soil solute concentration to quantitatively analyze solute concentrations. Based on this, the influence of different chloride solutes on the transport of water, heat, and solutes in sandy soil under freezing conditions was analyzed. The experiment results demonstrate that: (1) the concentration of solutes in soil water and its temperature are the main factors that affect the EC. The conversion between EC and concentration can quantitatively analyze the solute changes in the soil. (2) Different types of chloride affect the transport of water, heat, and solute in sandy soil. Compared with NaCl and KCl solutes, MgCl₂ solute soil column has a shorter freezing stability time, lower stable temperature, higher temperature drop rate, lower unfrozen water content, and larger variation amplitude under freezing conditions. (3) Compared with MgCl₂ and CaCl₂ solutes, the concentration of NaCl and KCl solution was more affected by cooling, and NaCl and KCl tended to accumulate in the upper layer obviously. In winter and spring at high latitudes, the sodium and potassium content in surface soil will increase due to the redistribution of salt caused by freezing, which will affect the growth of crops.

Brittle failures were observed in pile foundations during past earthquakes due to seasonally frozen ground. This paper introduces a new geosynthetic material derived from waste tires, i.e., polyurethane-bonded rubber particles and sand, termed PolyBRuS, for application around deep foundations to improve their seismic performance in cold regions. Cyclic triaxial tests were carried out at various temperatures, confining pressures, and freeze–thaw cycles to assess the cold-weather dynamic characteristics of PolyBRuS. The results show that the material behaves as a nonlinear viscoelastic material at an axial strain of less than 1%. Its dynamic elastic modulus rises after freezing and continues to increase as temperature drops, but it is much less sensitive to confining pressures and freeze–thaw cycles; its damping ratio rises significantly with increasing axial strains and decreasing subfreezing temperatures and declines moderately with increasing freeze–thaw cycles. Compared with natural soils, its dynamic elastic modulus is similar to those of unfrozen fine-grained soils and is much less sensitive to subfreezing temperatures; its damping ratio is comparable to that of fine-grained unfrozen soils and is substantially higher than frozen soils at subfreezing temperatures. These characteristics make this material an excellent candidate to replace local soil around deep foundations for vibration reduction and seismic hazard mitigation in cold regions.

As a material for road deicing and snow removal, electrically conductive concrete (ECON) can convert electrical energy into thermal energy to automatically melt ice and snow, avoiding manual and mechanical operations. However, to achieve ideal electrical conductivity, the content of single-doped conductive fillers in ECON needs to be high, which leads to poor workability of ECON and agglomeration of conductive fillers. Combing conductive fillers with different scales helps reduce the content of single-doped conductive fillers in ECON. This study prepared composite conductive concrete using multilayer reduced graphene oxide (RGO), carbon fiber, and steel fiber as conductive fillers. The effect of multilayer RGO on composite conductive concrete’s compressive strength, flexural strength, and electrical conductivity was investigated. Besides, the mechanism of RGO on composite conductive concrete's conductive network was analyzed by scanning electron microscope (SEM). Results showed that the 28-day mechanical properties and electrical conductivity of composite conductive concrete first increased and then decreased. Composite conductive concrete containing RGO with 0.4% cement weight (RGO-0.4) exhibited better mechanical and electrical properties. The improvement of the performance of composite conductive concrete was attributed to the filling effect of RGO on the gaps of concrete matrix and the wrapping effect of graphene flocs on fibrous conductive fillers because these effects increased the compactness of the matrix and conductive contact area, respectively. Also, a snow melting test was carried out using an RGO-0.4 slab at an ambient temperature of −15°C. The snow melting efficiency was improved, showing that 20-cm-thick snow melted in 1.2 h. In conclusion, the hybrid addition of RGO and fibrous conductive fillers has positive effects on ECON, providing a new way to develop ECON.