Seasonal Frozen Soil Research Articles

Investigation of the Temperature and Horizontal Freezing Force of Loess in Three-Dimensional Freezing.

Seasonal frozen soil has significant impacts on changes in soil mechanical properties, settlement, and damage to foundations. In order to study variations in the temperature and horizontal freezing force of loess during three-dimensional freezing, a three-dimensional freezing model test of loess was carried out. This experiment analyzed and studied the soil temperature change distribution characteristics, horizontal freezing force distribution rules, and water migration phenomena caused by temperature. The research results show that the temperature change in soil samples exhibits a "ring-like" decrease from the outside to the inside. When the soil temperature reaches the supercooling point, the cooling curve jumps and rises, and this is accompanied by a stable section with constant temperature. In the late freezing period, the temperature rate drops slowly. Under the action of freezing, the horizontal freezing forces at different positions have similar change characteristics and can be divided into four change stages: stable stage, rapid freezing stage, "secondary" freezing stage, and freezing-shrinkage-rebound stable stage. At lower moisture contents, loess samples undergo freeze-thaw shrinkage during the freezing process. During the rapid freezing stage of soil samples, the water in the soil sample migrates and causes secondary freezing. After the rapid freezing stage, the soil temperature continues to decrease, and the horizontal freezing force no longer decreases.

A distributed modeling approach to water balance implications from changing land cover dynamics in permafrost environments

There is 78 % permafrost and seasonal frozen soil in the Yangtze River’s Source Region (SRYR), which is situated in the middle of the Qinghai-Xizang Plateau. Three distinct scenarios were developed in the Soil and Water Assessment Tool (SWAT) to model the effects of land cover change (LCC) on various water balance components. Discharge and percolation of groundwater have decreased by mid-December. This demonstrates the seasonal contributions of subsurface water, which diminish when soil freezes. During winter, when surface water inputs are low, groundwater storage becomes even more critical to ensure water supply due to this periodic trend. An impermeable layer underneath the active layer thickness decreases GWQ and PERC in LCC + permafrost scenario. The water transport and storage phase reached a critical point in August when precipitation, permafrost thawing, and snowmelt caused LATQ to surge. To prevent waterlogging and save water for dry periods, it is necessary to control this peak flow phase. Hydrological processes, permafrost dynamics, and land cover changes in the SRYR are difficult, according to the data. These interactions enhance water circulation throughout the year, recharge of groundwater supplies, surface runoff, and lateral flow. For the region’s water resource management to be effective in sustaining ecohydrology, ensuring appropriate water storage, and alleviating freshwater scarcity, these dynamics must be considered.

Study of hydrothermal characteristics of large‐scale water conveyance trunk canals in seasonally frozen ground regions under the influence of different initial water contents

AbstractIn seasonal frozen soil, freezing and thawing can change the physical and mechanical properties and affect slope stability. There are complex moisture conditions in the main water transfer canal. A study of the hydrothermal evolution of canals with different initial water contents under the action of freezing and thawing is of great importance for the prevention and control of canal slope slides. Hydrothermal coupling models are the key to revealing the canal's hydrothermal evolution. As some of the modeling parameters in the current hydrothermal coupling model are based on empirical values, particularly those in the van Genuchten equation, which are not necessarily related to soil properties, they are not suitable for analyzing the hydrothermal evolution of canals. This paper determines the soil‐water characteristic curve from the cumulative curve of particle gradation in the subsoil, and then determines the hydraulic parameters of the subsoil using the VG model, which then corrects the hydrothermal coupling model. The method of modifying the hydrothermal coupling model is original, which makes the model more realistically reflect drainage soil characteristics. During freezing and thawing of channel slopes with different initial water contents (21%, 25%, 29%, 33%, 37%, and 41%), temperature field, water field, and ice content distributions were investigated. Using the V‐G model, the optimal parameters for canal subsoil were a = 0.06, n = 1.2, and m = 0.17, and temperature distribution trends between canals with different water contents were basically similar. Water will accumulate at the bottom as the liquid water content increases at the canal boundary.

Subsurface Drainage for Minimizing the Risk of Subsoil Compaction in Seasonally-Frozen Soils

HighlightsSubsoil is highly susceptible to compaction based on texture and packing density.Imperfect natural drainage increases the risk of subsoil vulnerability to compaction.Irrespective of drain spacing, the risk for subsoil compaction was high.The upper soil layer protects the subsoil from compaction at drain spacing = 12 m in this soil. Abstract. Subsoil compaction negatively impacts soil hydrological processes and promotes anaerobic conditions, reducing soil productivity and enhancing greenhouse gas emissions from the soil. Additionally, it is challenging and expensive to alleviate subsoil compaction once it occurs. The objective of this study was to assess the effectiveness of subsurface drainage in minimizing the risk of subsoil compaction under different weather patterns in Southern Manitoba. The assessment of the risk of subsoil compaction was done in two stages. That is, 1) determination of the subsoil’s intrinsic susceptibility to compaction based on soil texture and packing density and 2) determination of the wetness condition of the subsoil and ability of the strength of the upper layer of the soil to protect the subsoil. A long-term simulation of soil water content data (i.e., 2000 to 2015) under different drainage spacings (i.e., 8, 10, 12, 15, 25, and 30 m) maintained at 0.9-m depth was obtained to determine the soil wetness condition using a validated HYDRUS 2D/3D model. The study showed that the subsoil’s intrinsic susceptibility level to compaction at the study site was high, implying that the subsoil had a very weak natural potential to resist compaction. Throughout the 16 years considered, the subsoil wetness condition was either “moist” or “wet” irrespective of drain spacing, making the subsoil very vulnerable to compaction. However, for drain spacing = 12 m, the subsoil was found to be protected for most of the spring operation period with minimum impact on the spring operation days based on the criterion that the soil water content in the upper layer should be equal to or less than 90% of the lower plastic limit. In contrast, drain spacing wider than 12 m resulted in a lack of protection of the subsoil for 21 to 50 d. The intrinsic susceptibility of the subsoil to compaction, the “imperfect” internal natural drainage, and excess soil water during the early growing season suggest it is critical to consider the benefits of installing subsurface drains at narrower spacing (= 12 m) because of the ability to improve the soil wetness condition for field operations and prevent short and long-term impacts due to subsoil compaction. Keywords: Bulk density, HYDRUS (2D/3D), Lower plastic limit, Sandy loam, Soil water content.

Effects of permafrost degradation on soil organic matter turnover and plant growth

Continuous climate warming in northeastern China has intensified the melting of permafrost, leading to its degradation. The thawing of permafrost increases the instability of wetland soil organic matter and accelerates decomposition; this will inevitably have a strong impact on the transformation of soil organic matter and the process of vegetation growth. Therefore, the present study used the Xing’an Mountains in Northeast China as the research area. We selected typical marsh areas and analyzed the thickness of the active layer and seasonal frozen soil at different degrees of permafrost degradation. Soil and plant samples (herbs: Carex schumidtii; shrubs: Vaccinium uliginosum; trees: Betula papyrifera) from foliage, roots, and stems were collected at different depths to determine the carbon and nitrogen stable isotope contents in soil and plants. Analysis of variance and multiple linear regression were used to examine the impact of frozen soil degradation on soil organic matter turnover and vegetation growth. The results showed that the thickness of the active layer is increasing, and the amount of seasonal frozen soil is decreasing in the Xing'an Mountains. The δ13C, δ15N, ɛδ13C, and ɛsoil15N values of different depths of permafrost were significantly different (P < 0.05). The foliage, roots, and stems of C. schumidtii, V. uliginosum, and B. papyrifera under different degrees of permafrost degradation were significantly different (P < 0.05), except for the δ13C value of B. papyrifera roots. Soil isotopic composition, and therefore SOM quality, was dependent on the isotopic composition of incoming biomass (foliage, roots, and stems).

Factors effecting the freeze thaw process in soils and reduction in damage due to frosting with reinforcement: a review

Seasonal frozen soil is widely distributed in China. The seasonal freeze-thaw (F-T) process of soil will adversely affect the safety and service life of the engineering structures in these areas. Therefore, it is necessary to thoroughly study the main factors affecting the F-T process of soil and prevent or control F-T damage. This study first briefly introduces the distribution of seasonal frozen soil in China and the damage of soil after F-T. Then, on the one hand, it discusses the influencing trends of soil properties after freeze-thaw cycles (FTC) based on the different soil structure, compaction degree, moisture content, freezing temperature, and FTC times. On the other hand, it analyzes the present major project prevention and control measures to the damage of soils subjected to the F-T. This study highlights the positive effect of soil reinforcement on improving soil mechanical properties and reducing F-T destruction to the soil construction. Finally, it prospects the optimal reinforcement methods for all kinds of soils during different F-T conditions based on further theoretical research and practical experience.

A Study of the Insulation Mechanism and Anti-Frost Heave Effects of Polystyrene Boards in Seasonal Frozen Soil

The damages resulting from frost heaving are the main causes of channel destruction in seasonal frozen soil regions. Over the years, many experimental studies have been performed regarding the channel anti-frost heaving in the Hetao irrigation area. However, there have been few experimental research studies conducted regarding the insulation and anti-frost heave effects of polystyrene boards (EPS) of different thicknesses. Therefore, in order to explore the insulation mechanism and anti-frost heave effects of precast EPS laid under the conditions of different thicknesses, an anti-frost heave test field was established in the Hetao irrigation area for the examination of the ground temperatures, frozen depths, frost heave amounts, and water content change rules. This study’s results showed that, for the laid EPS with thicknesses between 2 and 12 cm, the frost-heave reduction rate ranged from 53.2% to 92.6%; total accumulated temperature warming ranged from 248.65% to 565.93%; and the frozen depth reduction rate was between 59.8% and 75.9%. It was determined that the EPS per cm additions could effectively improve the ground temperatures at a buried depth of 30 cm by 0.78 °C, and reduce the frozen depth by 10.1 cm. Then, by comprehensively considering the positive economic and insulation effects, it was determined that the most appropriate thickness of the EPS laid under the precast concrete slabs in the Hetao irrigation area of Inner Mongolia was 8–10 cm.

PIC v1.3: comprehensive R package for computing permafrost indices with daily weather observations and atmospheric forcing over the Qinghai–Tibet Plateau

Abstract. An R package was developed for computing permafrost indices (PIC v1.3) that integrates meteorological observations, gridded meteorological datasets, soil databases, and field measurements to compute the factors or indices of permafrost and seasonal frozen soil. At present, 16 temperature- and depth-related indices are integrated into the PIC v1.3 R package to estimate the possible trends of frozen soil in the Qinghai–Tibet Plateau (QTP). These indices include the mean annual air temperature (MAAT), mean annual ground surface temperature (MAGST), mean annual ground temperature (MAGT), seasonal thawing–freezing n factor (nt∕nf), thawing–freezing degree-days for air and the ground surface (DDTa∕DDTs∕DDFa∕DDFs), temperature at the top of the permafrost (TTOP), active layer thickness (ALT), and maximum seasonal freeze depth. PIC v1.3 supports two computational modes, namely the stations and regional calculations that enable statistical analysis and intuitive visualization of the time series and spatial simulations. Datasets of 52 weather stations and a central region of the QTP were prepared and simulated to evaluate the temporal–spatial trends of permafrost with the climate. More than 10 statistical methods and a sequential Mann–Kendall trend test were adopted to evaluate these indices in stations, and spatial methods were adopted to assess the spatial trends. Multiple visual methods were used to display the temporal and spatial variability of the stations and region. Simulation results show extensive permafrost degradation in the QTP, and the temporal–spatial trends of the permafrost conditions in the QTP are close to those of previous studies. The transparency and repeatability of the PIC v1.3 package and its data can be used and extended to assess the impact of climate change on permafrost.

The age of sand wedges and its environmental significance at the southeast edge of Badain Jaran Desert

Sand wedge is a product of permafrost in cold climate, and it is of great significance to restore paleoclimate and paleoenvironment. Since the early 20th century, periglacial landforms such as sand, ice, and soil wedges and glacial mud have been intensively studied in North America, Europe, and Russia. Nevertheless, the distribution of desert areas in the permafrost regions after the last glacial period is still debated in academia. Particularly, in China, it has been argued that desert areas were not the parts of ancient permafrost regions. Moreover, the studies of ancient sand wedges are mostly limited to the last glacial period. In recent years, several groups of ancient sand wedges and glacial mud have been recognized in the Badain Jaran Desert. This filled the gap in the Chinese literature regarding ancient permafrost and proved that desert region belonged to the scope of permafrost regions during the last glacial period. The newly discovered sand wedges in the southeast Badain Jaran Desert comprise sand and gravel layers. Optically stimulated luminescence dating of the filler in the sand wedges suggests that they formed during the last glacial period and the late glacial maximum, in particular. The annual average temperatures in the Badain Jaran Desert during the last glacial period were approximately −3–−6°C, and it is 12–15°C cooler than present. The filler in sand wedges was mainly poorly sorted fine sand that was not transported from afar but from nearby sand dunes. According to the sand wedge groups of the last glacial period in the desert and seasonal frozen soil, we can infer that the Badain Jaran Desert was a part of the permafrost that may have been continuous and widespread. The extent and distribution of the Badain Jaran Desert in the last glacial period was probably different than today, reflecting the dynamic nature of sand dunes. According to the law of sand dunes’ movement in the Badain Jaran Desert, combining with the characteristics of aeolian sand of the desert’s ancient permafrost wedge can indirectly infer that three large desert areas of the Alxa Plateau were connected more than ten thousand years ago when the entire Alxa Plateau was part of the permafrost; furthermore, the desert hinterland and the surrounding sand dunes would have been frozen and the movement and development of the sand dunes would have been suppressed. Surface landscape and the kinetics of the sand and landform need to be studied further. While the Badain Jaran Desert was likely a part of the cryosphere climate zone during the last glacial period, whether the Chinese northern desert belonged to the frozen earth region is still questionable.

Water, Salt and Heat Influences on Carbon and Nitrogen Dynamics in Seasonally Frozen Soils in Hetao Irrigation District, Inner Mongolia, China

To investigate carbon (C) and nitrogen (N) dynamics in seasonally frozen soils under saline and shallow groundwater supply conditions, in-situ lysimeter experiments with different groundwater table depths (WTD = 1.8 and 2.2 m) were conducted in Inner Mongolia, China during the wintertime of 2012–2013. Changes in soil organic C and total N in multiple layers during various periods, as well as their relationships with soil water, salt, and heat dynamics were analyzed. Accumulation of soil organic C and total N during freezing periods was strongly related to water and salt accumulation under temperature and water potential gradients. Water and salt showed direct influences on soil C and N dynamics by transporting them to upper layer and changing soil microbial activity. Salt accumulation in the upper layer during freezing and thawing of soil affected microbial activity by lowering osmotic potential, resulting in lower C/N ratio. Nitrogen in soil tended to be more mobile with water during freezing and thawing than organic C, and the groundwater table also served as a water source for consecutive upward transport of dissolved N and C. The changes in C and N in the upper 10 cm soil layer served as a good sign for identification of water and salt influences on soil microbial activity during freezing/thawing.

1961~2010年呼和浩特市区地温及季节冻土的变化特征

对呼和浩特市区50a (1961~2010年)地温及冻土气象观测资料整理和分析的基础上，研究了地温和冻土随时间的演变规律，探讨其基本事实、特征及变化原因。结果为：50年间呼和浩特市区地温升高显著(p < 0.05)、土壤封冻状态及最大冻土深度均发生较大变化，且不同年代变化幅度也不尽相同：90年代地温和土壤封冻状态迅速变化，10年代地温增温最为剧烈、土壤封冻状态变化最为显著；最大冻土深度则表现为由浅到深、再到浅的过程。地温与气温的变化不同步，地温的变化滞后于气温，春季地温升高幅度大于冬季。日最低平均地表温度和日最高平均地表温度较其它两类地温增温明显，气候倾向率分别为0.45/10a和0.43℃/10a；平均解冻日的大幅提前(基本表现为每10年提前7天左右)是引起封冻天数变化的直接原因；70~90年代为冻土深度最大的时段，最大冻土深度10年代较70~90年代约减少17 cm。 Based on the collection and analysis of meteorological observation data of ground temperature and seasonal frozen soil in Hohhot City during 1961-2010, time-variations of ground temperature and seasonal frozen soil were studied, and the basic facts, characteristics and reasons were also discussed. The results showed that: the ground temperature rose remarkably (p < 0.05), and the soil frozen state and maximum depth of frozen ground changed greatly within the fifty years. Furthermore, their degrees of changing were different among ages. The ground temperature and soil frozen state changed rapidly in 1990s, and the most severe changes of them were occurred in the first ten years of twenty first century. The maximum depth of frozen ground represented the process as: from shallow to deep, then to shallow during 1961-2010. Changes in ground temperature and air temperature were not synchronized, and the change of ground temperature lagged behind the air temperature. The rise extent of ground temperature in spring was larger than that in winter. Daily minimum and maximum mean surface temperature were increased obviously than the other two ground temperatures, and their climate tendency rates were 0.45/10a and 0.43˚C/ 10a respectively. The substantial advance of average thawing day (about 7 days in advance every 10 years) directly affected the frozen days. 1970s to 1990s was the greatest period of maximum depth of frozen soil, and the maximum depth of frozen soil in the 10s was decreased by about 17 cm compared with the 70s-90s.

Effect of hydraulic distribution on the stability of a plane slide rock slope under the nonlinear Barton-Bandis failure criterion

In this paper, stabilities of a plane slide rock slope under different hydraulic distributions were studied based on the nonlinear Barton-Bandis (B-B) failure criterion. The influence of various parameters on the stability of rock slopes was analyzed. Parametric analysis indicated that studying the factor of safety (FS) of planar slide rock slopes using the B-B failure criterion is both simple and effective and that the effects of the basic friction angle of the joint (phi(b)), the joint roughness coefficient (JRC), and the joint compressive strength (JCS) on the FS of a planar slide rock slope are significant. Qualitatively, the influence of the JCS on the FS of a slope is small, whereas the influences of the fb and the JRC are significant. The FS of the rock slope decreases as the water in a tension crack becomes deeper. This trend is more significant when the flow outlet is blocked, a situation that is particularly prevalent in regions with permafrost or seasonal frozen soil. Finally, the work is extended to study the reliability of the slope against plane failure according to the uncertainty from physical and mechanics parameters.

Research on Frost Heaving of Subgrade Filling in Seasonal Frozen Soil Area

Research on frost heaving of high speed railway subgrade filling in seasonal frozen soil area is developed indoor. Through freezing and thawing strength and frost heaving amount test, the research analyzes factors affecting frost heaving of subgrade filling, points out that water content, fine stuff admixing amount and plasticity of fine-grained soil have relatively large influence on frost heaving, while freezing temperature and freezing and thawing cycle index have relatively small influence. Water content is main factor to have effect on frost heaving of subgrade filling. When the water content reaches to some certain value, even coarse-grained soil can produce considerable frost heaving amount. Therefore, taking effective waterproof and drainage measures is of great importance in subgrade frost heaving prevention and treatment.

The Analysis of Finite Element about the Interaction between Seasonal Frozen Soil and Tower Pile Foundation

In the northern frozen-soil region,the heaving soil’s low temperature is the key factor that impacts the stability of foundation. This paper makes the heat-stress coupled numerical analysis on the cold expansion effect of the pile foundation to the Ulanhot-Baicheng 500kV transmission line engineering by finite element software ABAQUS. Firstly, the seasonal frozen soil’s temperature field should be calculated. Then, the temperature value acting as the temperature model’s initial condition is put into the structure model for computation, which can help to get the pile foundation’s stress field and strain field. The results show that, the stress state of pile-frozen soil under external load can be reflected accurately through the finite element model and the related parameters proposed, along with the finite element software.

Pile Foundation Antifreezing Measures Research in Seasonal Frozen Soil Region

Canal bridge and aqueduct main foundation types include well column, pier, bored piles, bent pile etc. Most of these foundations are in low-lying conduit. The water content of foundation soil is very rich. Especially pile foundation in the drain, due to the high underground water level, pile foundation around soil is in a state full of water. So such type of foundation freeze injury phenomenons are very serious. In order to solve such freeze injury problems, some antifreezing measures are adopted.

Fault Current-Division Factor of Substation Grounding Grid in Seasonal Frozen Soil

The determination of the maximum ground fault current, which has a close relation to the maximum hazardous step-and-touch voltage, is essential for the safety of a substation. Seasonal frozen soil changes the grounding resistances of the substation grounding grids and the tower footing devices, which seasonally influences the maximum grid current. This paper first introduces the method to calculate the fault current-division factor, and then discusses the influence of the seasonal frozen soil layer on it by using the proposed method. Based on the cases of two substations connected by the transmission lines and without neutrals or other connection paths, the influence of several factors on the fault current-division factor, including the thickness of seasonal frozen soil, and the number of transmission lines with overhead ground wire connected to the substation grounding grid, is analyzed. It is reasonable to consider the influence of the seasonal frozen soil on the fault current-division factor in grounding grid design. According to the analysis, adding vertical grounding rods to the grounding grid and the tower footing grounding device can almost eliminate this seasonal influence.

Discussion on Moisture Migration and Law of Frost Heave of Seasonal Frozen Soil in Hetao Irrigation Area, Inner Mongolia

Hetao irrigation area in Inner Mongolia is one of the four major irrigation areas in China, seasonal frozen soil is widely distributed in this area. Irrigation channel engineering experiences seriously freeze-thaw cycle many times in the long winter, its maintenance is the important and difficult point all long in irrigation channel engineering of Hetao irrigation area. For this, we analyze the moisture migration and law of frost heave characteristics of seasonal frozen soil in Hetao irrigation area.

Site Monitoring on Temperature Field Distribution of Asphalt Pavement in Seasonal Frozen Soil Region

As pavement bear the comprehensive effect of environment factors at the same time, its internal temperature field distribute complicatedly and difficult to be predicted. Due to the internal temperature field of pavement is the key of pavement performance and service durability, this paper improved the layout scheme of the temperature field, based on the previous test scheme of factual temperature field. Using the factual temperature field data of asphalt pavement, this paper studied on the temperature distribution characteristic of each layer, summed the temperature filed distribution rule of asphalt pavement and put forward the control points of pavement design low temperature.This paper verified the universality of low design temperature in SHRP (Strategic Highway Research Program) and pointed out some problems like the low temperature design temperature (Tmin) had quite large safe factor.

Reply [to “Comment on ‘Water Movement into Seasonally Frozen Soils’ by Douglas L. Kane and Jean Stein”

Water Resources ResearchVolume 21, Issue 7 p. 1053-1054 Commentaries Reply [to “Comment on ‘Water Movement into Seasonally Frozen Soils’ by Douglas L. Kane and Jean Stein”] Douglas L. Kane, Douglas L. KaneSearch for more papers by this authorJean Stein, Jean SteinSearch for more papers by this author Douglas L. Kane, Douglas L. KaneSearch for more papers by this authorJean Stein, Jean SteinSearch for more papers by this author First published: July 1985 https://doi.org/10.1029/WR021i007p01053Citations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume21, Issue7July 1985Pages 1053-1054 RelatedInformation

Comment on “Water Movement into Seasonally Frozen Soils” by Douglas L. Kane and Jean Stein

Comment on “Water Movement into Seasonally Frozen Soils” by Douglas L. Kane and Jean Stein