Journal of Cold Regions Engineering

Railways constructed in cold regions can experience localized frost heave in the winter as well as track softening during the spring thaw. These phenomena are great challenges for road and railway foundations on seasonally frozen ground and must be considered by railway operators. To address these problems, temporary wooden shims can be used to smooth existing tracks; reductions in train speeds may also be mandated. The degree of susceptibility of a given section of a track to frost can be determined by considering the main preconditions allowing heave and frost to occur. This study reviews several frost susceptibility surveys that show the correlation between soil properties and laboratory results of frost heave tests. A summary of treatment methods for frost action is presented and a straightforward design procedure is provided to first evaluate the frost susceptibility of soils and the frost hazard potential in Canada as well as predict the frost penetration depth, and then select the appropriate frost-treatment method based on previous studies and standards. The outcome of this study is a five-step tool that can be applied by Canadian engineers to first evaluate the frost susceptibility degrees of soils based on the soil properties in each province and then select the appropriate treatment method considering the frost hazard potential.

Abstract

The utilization of natural zeolite as a supplementary cementitious material to improve the overall performance of concrete has been an interesting practice. However, limited research has been conducted on natural zeolite, which contains approximately 15% void space, to address the freeze–thaw (F–T) impact in a severe environment of cold regions. This study determined the resistance to freezing and thawing of nonair-entrained concrete made with up to 20% by mass natural clinoptilolite zeolite replacement of portland cement for up to 300 alternate cycles per current standards. The influence of clinoptilolite zeolite on the workability and air content of fresh mixes was measured before preparing the concrete specimens. The water absorption, void content, and splitting tensile strength of concrete were assessed 28 days prior to F–T testing. The resistance to freezing and thawing of concretes was monitored through the dynamic modulus of elasticity based on the fundamental transverse frequency, durability factor, and mass loss of beam specimens having a size of 76 × 76 × 406 mm. The chloride ion permeability via surface resistivity of all concrete beams was examined before and after freezing and thawing. Results revealed that using zeolite could entrain (and/or entrap) a slightly higher air content but decrease the workability of concrete. The application of up to 20% clinoptilolite zeolite exhibited a slightly higher water absorption and porosity in both mortar and concrete compared to the control samples. The favorable curing environment and the pozzolanic performance of 5%–15% zeolite produced a dense matrix, leading to a higher dynamic modulus of elasticity, increased frost resistance, and minimal mass loss against freezing and thawing. Using zeolite also led to a moderate level of chloride ion penetrability after 300 F–T cycles. Based on the results, the optimum dosage of clinoptilolite zeolite with the replacement of portland cement was found to be 10% due to the satisfactory resistance to the F–T impact, maintaining the structural integrity for up to 300 cycles.

Practical Applications

The present study investigated the effect of using natural clinoptilolite zeolite as the supplementary cementitious material in the concrete against the freeze–thaw impact. Typically, the air-entraining admixture is applied to form the air voids in the concrete so that the ice crystal may occupy that void during the freezing environment to reduce the overall hydraulic pressure. However, every 1% volume of entrapped and/or entrained air can reduce the strength of concrete by up to 5%, while the maximum allowable air content is up to 5%–8% in a severe environment. Therefore, applying this strategy could significantly decrease the performance of the concrete. Since zeolite is a highly porous material, it will entrain (and/or entrap) air voids in the concrete where the ice crystal may form during the freezing environment, leading to lower hydraulic pressure. Hence, the use of air-entraining admixtures can be reduced and/or eliminated in the concrete without compromising the strength. Moreover, the pozzolanic activity of clinoptilolite zeolite will increase the strength and enhance the microstructural development, leading to the production of additional hydration reaction products along with finer pore size distribution of concrete microstructure.

Coal mine shaft excavation with the freezing method causes surrounding rock deformation under lateral unloading. In this paper, the failure process of frozen sandstone under lateral unloading was studied based on the acoustic emission (AE) response. The point where the deformation of rock samples under lateral unloading accelerates was taken as the plastic yield critical point (PYCP). The PYCP was defined as a fracture warning point. The mechanical properties of frozen rock samples under lateral unloading were also studied according to the AE response, and a damage model was established based on the number of cracks. The research showed that the number of cracks under lateral loading and cumulative acoustic emission energy in frozen sandstone increased slowly with time before the PYCP was reached and rose exponentially after the PYCP was reached. Following the sandstone (20°C) freezing, the peak stress under lateral unloading increased by 2.3–3 times and accounted for 52%–68% of the triaxial compressive strength. The peak stress increased with the initial confining pressure of the frozen rock sample, with a larger value indicating more severe damage. The model results were close to the experimental results before peak stress was reached, and the number of cracks could represent the damage degree and fracture level of the frozen sandstone.

Monitoring road surface temperatures is crucial to establishing winter maintenance strategies by the State Departments of Transportation (State DOTs) in the United States. Traditionally, transportation agencies rely on the information provided by Road Weather Information Systems (RWIS) for road surface temperatures along roadways. However, these systems are costly and only provide estimates at specific locations, resulting in distant areas being under-represented. In recent years, some interpolation techniques have been considered to address this gap by estimating the road surface temperatures between the RWIS stations. Nevertheless, these techniques are only valid when the RWIS data are available. This study aims to estimate the road surface temperatures using forecast weather data which are available at high spatial resolution in the National Weather Service Database maintained by the National Oceanic and Atmospheric Administration (NOAA). To this end, road surface temperature data were collected from roadways using a vehicle-mounted infrared temperature sensor. Furthermore, the associated forecast weather parameters from the National Weather Service database were used to develop relationships between the publicly available weather forecast data and the actual road surface temperatures using multiple linear regression. The authors developed two estimation models for dark and light groups and leveraged the gridded forecast weather data from the national weather service database to visualize the estimated road surface temperatures along roadways using a GIS approach. The results showed that the ambient temperature, relative humidity, wind speed, average temperature of the previous day, and road surface conditions (wet/dry) are statistically significant in estimating the road surface temperatures using gridded forecast weather data. The performance of the models was validated, and satisfactory accuracy metrics (i.e., mean absolute error) of approximately 1°C and 2°C were achieved for the dark and light groups, respectively. The proposed method was implemented in the TxDOT Wichita Falls district as a part of a Snowplow Operations Management System to provide information about the estimated road surface temperatures to transportation managers for the 2021–2022 winter season. This information facilitates establishing proactive anti-icing measures in locations where possible low surface temperatures are expected. The findings of this research contribute to a better understanding of the influence of publicly available weather forecast parameters on road surface temperatures.

In austere environments, such as northern regions, remote communities face many challenges such as permafrost warming and significant infrastructure deficit. With the increasing demand for soil stabilization methods beneath structures, adapting building designs has become a vital requirement for a sustainable and resilient future in the northern climate. This study proposes a novel improved framework integrated building information modeling (BIM), computational fluid dynamics (CFD), and heat transfer analysis to quantify the effects of infrastructure development on permafrost ground. Results reveal that buildings have altered the ground thermal regime, causing permafrost thawing at a variable rate depending on different factors. Building clearance height above the ground, soil physical property, building floor thermal conductivity, and wind speed and direction are vital factors in this scenario. The study also found that raising buildings by one meter above the ground is recommended for the northern climatic regions as it reduces the thermal stresses on the permafrost. Further, the thermal load due to buildings generated in the present study can also be used in the structural analysis for permafrost buildings.

Abstract

Field tests indicate that strong ice-induced vibration is a common safety risk for offshore platform structures in cold regions. The isolation principle may provide a solution to reduce ice-induced vibrations, considering the position and movement direction of the ice sheet interacting with platform piles. In this study, an isolation cone system is designed and installed on a mooring dolphin platform in the Bohai Sea. The isolation cone system comprises cones and laminated rubber bearing isolators and is installed on the platform piles to reduce dynamic coupling between the ice sheet and platform structure. Field tests indicate that the ice-induced vibration acceleration of the platform structure is significantly reduced and the isolation cone system can have a significant affect in reducing ice-induced vibration of offshore platform structures.

Practical Applications

Safety risks exist for offshore platform structures under ice loads in cold regions; for example, offshore platform structure collapse, pipeline rupture. In recent years, engineers and academic researchers have constantly explored options to reduce the safety threat caused by ice load for offshore platform structures, specifically the ice-induced vibration of offshore structures. An isolation cone system is designed based on the isolation principle and applied to the offshore platform in the Bohai Sea, China. The measured data indicate the effect of reducing the ice-induced vibration response of the offshore platform structure. Meanwhile, the structural design of the isolation cone system can provide a reference for the vibration reduction design of bridges or buildings. In addition, the isolation cone system structure can be further optimized and used in the field of mechanical engineering.

Freeze–thaw cycles in seasonal permafrost areas are a dominant cause of road damage. Therefore, the roadbed fill must be frost-resistant. In this study, taking the experimental section of the asphalt concrete pavement structure of the Zhangcheng Expressway in the seasonally frozen soil area of Hebei Province as an example, three working conditions were selected: a low embankment with a waterproof geotextile partition layer, a low embankment with a gravel layer + extruded polystyrene (XPS) board, a high embankment with a gravel layer + two pieces of cloth, and a waterproof geomembrane. After 2 years of tracking and analysis of the measured data, the subgrade temperature distribution law was derived in terms of time and depth to obtain the freezing depth under each working condition. The experimental results showed that the gravel bedding layer, XPS plate, and geosynthetic materials had a significant effect on the prevention and mitigation of road disease, and therefore, their application must be promoted.