Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
5.8
3.9
Journals
Sustainability
Special Issues
Enhancing Subgrade Stability in Complex Environment for Sustainable Road
sustainability-logo
Submit to Sustainability Review for Sustainability Propose a Special Issue

Journal Menu

► Journal Menu

Journal Browser

► Journal Browser
share announcement

Enhancing Subgrade Stability in Complex Environment for Sustainable Road

A special issue of Sustainability (ISSN 2071-1050). This special issue belongs to the section "Sustainable Transportation".

Deadline for manuscript submissions: closed (30 June 2023) | Viewed by 23680

Special Issue Editors

Dr. Feng Zhang

E-Mail Website
Guest Editor
School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China
Interests: soil Improvement; subgrade stability; solid waste recycling utilization in subgrade
Dr. Rui Zhang

E-Mail Website
Guest Editor
School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China
Interests: utilization of special soils in subgrade; subgrade stability; life cycle assessment
Dr. Weiguang Zhang

E-Mail Website
Guest Editor
School of Transportation, Southeast University, Nanjing 211189, China
Interests: theoretical study and practical application in pavement structure defect detection and health monitoring using surface wave, TSD, 3D GPR
Special Issues, Collections and Topics in MDPI journals
Dr. Ruxin Jing

E-Mail Website
Guest Editor
Department of Engineering Structure, Delft University of Technology, Delft, The Netherlands
Interests: pavement durability; green and sustainable pavement materials
Special Issues, Collections and Topics in MDPI journals
Dr. Chuang Lin

E-Mail Website
Guest Editor
School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China
Interests: geosynthetics; unsaturated soil; slope stability in cold regions
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

We are calling for submissions to a Special Issue of Sustainability related to new theories, methodologies, and technologies that enhance the subgrade of roads that are facing challenges related to ecology and the engineering environment, including temperature, moisture, loading, etc.

The performance requirements for a sustainable road include, but are not limited to, long-life, durability, safety, environmental protection, low CO2 emissions, etc. To achieve these requirements, researches have initiated research in the following fields: environmentally friendly materials to improve soil properties, new types of subgrade structures to adapt to complex environmental conditions, quick and effective detection and evaluation technologies, low-disturbance maintenance methodologies for the road structure and traffic flow, and the development of new manuals and standards for sustainable roads. These initiatives have contributed to the development of sustainable roads. Therefore, this Special Issue aims to highlight new developments and challenges in the area of sustainable subgrade. The Special Issue focuses on new theories, methodologies, and technologies that satisfy the demand of sustainable road design, construction, and maintenance by improving soil properties and the durability performance of subgrades. We welcome papers on, but not limited to, the following topics:

  • Property improvement of problematic soils by considering the ecology and engineering environment;
  • New types of subgrade structures enhancing the long-term engineering stability and reducing the ecological disturbance;
  • Performance evaluation based non-destructive detection for a sustainable subgrade;
  • Non-excavation and low-disturbance repair techniques for subgrade;
  • Life-cycle assessment for sustainable subgrade;
  • Recycling solid waste as subgrade;
  • Geosynthetics-stabilized subgrades;
  • Case studies involving sustainable subgrades.

We look forward to receiving your contributions.

Dr. Feng Zhang
Dr. Rui Zhang
Dr. Weiguang Zhang
Dr. Ruxin Jing
Dr. Chuang Lin
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Sustainability is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • subgrade stability
  • environmentally friendly subgrade
  • problematic soil improvement
  • non-destructive detection and evaluation
  • non-excavation and low-disturbance repair techniques
  • recycling utilization of solid waste
  • case studies

Published Papers (18 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

12 pages, 2972 KiB  
Article
Road Performance Evaluation of Unburned Coal Gangue in Cold Regions
by Yan Feng, Liang Shi, Deng Ma, Xiaohe Chai, Chuang Lin and Feng Zhang
Sustainability 2023, 15(18), 13915; https://doi.org/10.3390/su151813915 - 19 Sep 2023
Cited by 3 | Viewed by 666
Abstract
At present, the cumulative storage of coal gangue in China exceeds 7 billion tons, covering an area of approximately 70 km2. The engineering application of unburned coal gangue is mainly utilized as concrete aggregate or cement production after the overfire process. [...] Read more.
At present, the cumulative storage of coal gangue in China exceeds 7 billion tons, covering an area of approximately 70 km2. The engineering application of unburned coal gangue is mainly utilized as concrete aggregate or cement production after the overfire process. However, it is prone to environmental pollution and has limited consumption. Using unburned coal gangue as roadbed filling not only alleviates the difficulty of land acquisition and soil collection for road constructions in mining areas, but also consumes a large amount of accumulated unburned coal gangue. This study conducts research on the road performance of unburned coal gangue. A series of laboratory tests have been performed to determine the physical and chemical properties of the unburned coal gangue and its performance as a filling material in cold regions. The influence of compaction effort, clay content, and number of freezing–thawing cycles on the mechanical performance of the unburned coal gangue was investigated. The typical unburned coal gangue in the Heilongjiang region is mainly composed of SiO2, Al2O3, and Fe2O3, which accounts for approximately 91% of the total mass. The unburned coal gangue meets the minimum CBR requirement of 8% after 7 freezing–thawing cycles. This study helps fully and reasonably utilize typical unburned coal gangue in the local area, providing technical support for achieving the overall goal of “green development, conservation and intensification, and low-carbon environmental protection”. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

22 pages, 9209 KiB  
Article
Field Comprehensive Testing and Study on New Subgrade Structure of High-Speed Railway in Diatomaceous Earth Region
by Huiqin Guo, Qian Su, Taifeng Li, Qianli Zhang, Mahantesh M. Nadakatti, Hongye Yan and Feng Chen
Sustainability 2023, 15(8), 6912; https://doi.org/10.3390/su15086912 - 19 Apr 2023
Viewed by 941
Abstract
Part of the Hang-Tai High-speed Railway (Hangzhou via Shaoxing to Taizhou in Zhejiang Provence) in China passes through the diatomaceous earth area, which is the first time in the history of Chinese high-speed railway construction. This type of soil has significant compressibility, swelling [...] Read more.
Part of the Hang-Tai High-speed Railway (Hangzhou via Shaoxing to Taizhou in Zhejiang Provence) in China passes through the diatomaceous earth area, which is the first time in the history of Chinese high-speed railway construction. This type of soil has significant compressibility, swelling and disintegration. Diatomaceous earth also shows a sharp reduction in strength when exposed to water, which severely impacts the safety of the project. However, no studies have been carried out on the engineering practice of building a high-speed railway in the diatomaceous earth area in China. Moreover, there is limited experience in the construction of ballastless track through the diatomaceous earth area. In order to ensure the stability of the high-speed railway subgrade in diatomaceous earth area, and considering the high level of precipitation in the location of this railway, a kind of waterproof and drainage subgrade (WDS) is proposed to reduce the influence of precipitation on the strength of the diatomaceous earth foundation. The subgrade has a flexible waterproof and drainage layer (WDL) inside, which consists of capillary waterproof and drainage plates and medium-coarse sand. In the present study, field tests including immersion tests and excitation test are carried out on a subgrade test section to verify the subgrade structure. The tests mainly focus on construction technology, waterproof performance and dynamic characteristics. The studies show that the subgrade bed with the WDL can effectively avoid the diatomaceous earth foundation from rainfall interference and maintain the long-term stability of the subgrade. The flexible WDL in WDS has a significant energy dissipation effect in comparison with the traditional subgrade (TS) filler and can play a key role in vibration damping, promoting the attenuation of dynamic response in the downward and cross-sectional directions within the subgrade. The dynamic response of the WDS attenuates along the depth. In comparison with the existing high-speed railway subgrade measured data, its dynamic response attenuation coefficient is within acceptable limits. The laying of the WDL does not change the subgrade dynamic characteristics transfer law. The proposed structure meets the requirements of ballastless track construction for high-speed railways, and the WDL can be used in the design of high-speed railways for enhanced drainage protection in diatomaceous soil areas or other special soil areas. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

25 pages, 8757 KiB  
Article
Bearing Characteristics of Composite Foundation Reinforced by Geosynthetic-Encased Stone Column: Field Tests and Numerical Analyses
by Kaifeng Wang, Mengjie Liu, Jie Cao, Jiayong Niu and Yunxia Zhuang
Sustainability 2023, 15(7), 5965; https://doi.org/10.3390/su15075965 - 29 Mar 2023
Cited by 1 | Viewed by 1271
Abstract
In order to study the bearing characteristic of the geosynthetic-encased stone column (GESC) on the composite foundation, a series of field tests and numerical simulation were carried out on the composite foundations reinforced by the traditional stone column and the GESC. The pile–soil [...] Read more.
In order to study the bearing characteristic of the geosynthetic-encased stone column (GESC) on the composite foundation, a series of field tests and numerical simulation were carried out on the composite foundations reinforced by the traditional stone column and the GESC. The pile–soil stress ratio, excess pore water pressure and lateral displacement of two kinds of composite foundations were monitored. The effects of geotextile stiffness, geotextile wrapping length and gravel internal friction angle on the composite foundation with the GESC were analyzed by establishing different numerical models. The results show that the GESC can bear larger loading compared with the traditional stone column. The pile–soil stress ratio of the composite foundation with the traditional stone column gradually increases from 1.1 to 1.5 with the increasing of the embankment height. However, the pile–soil stress ratio of the composite foundation with the GESC reaches 1.5 at the initial filling stage and increases to 1.7 with the filling construction. The drainage effect of the GESC is better than that of the traditional stone column, and the GESC can effectively improve the overall stiffness of stone column, so as to reduce the lateral displacement of soil mass. The increases of geotextile stiffness, geotextile wrapping length and gravel internal friction angle can improve the bearing performance of the composite foundation with the GESC. However, after geotextile stiffness and wrapping length reach a certain value, the influence of its lifting amount on the composite foundation will be reduced. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

18 pages, 9276 KiB  
Article
Mechanical Behavior of Hydrated-Lime–Liquid-Stabilizer-Treated Granular Lateritic Soils
by Kangwei Tang, Feng Zeng, Liang Shi, Long Zhu, Zining Chen and Feng Zhang
Sustainability 2023, 15(6), 5601; https://doi.org/10.3390/su15065601 - 22 Mar 2023
Cited by 1 | Viewed by 1461
Abstract
Granular lateritic soil is commonly used for road construction in humid tropical and subtropical regions. However, the high plastic clay content and poor particle distribution of some laterite materials make them unsuitable for bases and subbases. Lime treatment is a widely used method [...] Read more.
Granular lateritic soil is commonly used for road construction in humid tropical and subtropical regions. However, the high plastic clay content and poor particle distribution of some laterite materials make them unsuitable for bases and subbases. Lime treatment is a widely used method for improving problematic lateritic soil, and liquid ionic stabilizers are considered an environmentally friendly solution for reinforcing such soils. However, using only lime or only stabilizers may not be optimal. This study investigated the effect of treating granular lateritic soil with hydrated lime and a new liquid stabilizer, Zhonglu-2A (ZL-2A). A series of indoor tests, including compaction, California bearing ratio, and unconfined compressive strength tests, were conducted to evaluate the effects of hydrated lime content and stabilizer content on the mechanical properties, mineralogical composition, and microstructure of the soil. The results show that an increase in hydrated lime dosage increases the optimal moisture content and decreases the maximum dry density. The CBR of lime-stabilizer-treated laterite was at least 2–3 times higher than that of the only-lime-treated soil. The highest CBR was observed in samples treated with 0.2‰ ZL-2A stabilizer. The sample with 6% lime and 0.2‰ ZL-2A stabilizer exhibited the highest unconfined compressive strength, and a nearly linear increase was observed between the unconfined compressive strength and CBR. Further investigation of the stabilization mechanism using X-ray diffraction mineralogy analysis and scanning electron microscopy revealed that the inorganic substances of the ZL-2A stabilizer and the hydrated lime provided the basic conditions for the reaction and generated cementitious hydrates on the clay particles. The mixture of granular lateritic soil and hydrated lime was wrapped by the ZL-2A stabilizer, forming a complex spatial structure and improving the strength of the soil. To improve the bearing capacity of subgrades in actual subgrade engineering, a combination of a liquid ionic stabilizer and lime should be used to treat laterite. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

15 pages, 8094 KiB  
Article
Slope Stability and Effectiveness of Treatment Measures during Earthquake
by Linlu Zhou, Lei Su, Zhuang Wang, Dongchun Zhu, Wei Shi and Xianzhang Ling
Sustainability 2023, 15(6), 5309; https://doi.org/10.3390/su15065309 - 16 Mar 2023
Cited by 1 | Viewed by 1829
Abstract
Slopes are prone to instability during earthquakes, which will cause geological disasters such as landslides and pose a great threat to people’s lives and property. Therefore, it is necessary to analyze the stability of slopes and the effectiveness of treatment measures during earthquakes. [...] Read more.
Slopes are prone to instability during earthquakes, which will cause geological disasters such as landslides and pose a great threat to people’s lives and property. Therefore, it is necessary to analyze the stability of slopes and the effectiveness of treatment measures during earthquakes. In this study, an actual slope in the creeping slide stage was selected and located in an area where earthquakes occur frequently. Once the slope experiences instability, it will produce great damage. Therefore, a finite difference program, Fast Lagrangian Analysis of Continua in Two Dimensions (FLAC2D), was employed in the numerical simulation to explore the stability of the slope before and after treatment under earthquake action. Different from previous studies, this study explores the effectiveness of various treatment measures on slope stability during earthquake. The computed results show that the stability of the slope is greatly influenced by earthquakes, and the slope displacement under seismic conditions is far larger than that under natural conditions. Three treatment measures, including excavation, anti-slide piles, and anchor cables, can significantly reduce slope displacement and the internal force on anti-slide piles, and improve the stability of a slope during an earthquake. This will provide a valuable reference for the strengthening strategies of unstable slopes. The analysis technique as well as the derived insights are of significance for slope stability and the effectiveness of treatment measures. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

13 pages, 2191 KiB  
Article
Dynamic Strength Characteristics of Cement-Improved Silty Clay under the Effect of Freeze-Thaw Cycles
by Zheng Ma, Zhen Xing, Yingying Zhao and Yiru Hu
Sustainability 2023, 15(4), 3333; https://doi.org/10.3390/su15043333 - 11 Feb 2023
Viewed by 1761
Abstract
In the seasonally frozen soil regions of northern China, silty clay is widely used as a subgrade bed filler in heavy-haul railway construction. In this paper, the influence of freeze-thaw cycles on the dynamic strength properties (strength parameters and dynamic critical stress) of [...] Read more.
In the seasonally frozen soil regions of northern China, silty clay is widely used as a subgrade bed filler in heavy-haul railway construction. In this paper, the influence of freeze-thaw cycles on the dynamic strength properties (strength parameters and dynamic critical stress) of silty clay fillers before and after cement improvement was investigated by a series of dynamic triaxial tests under different confining pressure conditions, and the test results were quantified to analyze the improvement effects of cement improvement. The results show that cement modification can significantly improve the dynamic strength parameters (dynamic strength, dynamic strength index, and critical dynamic stress) of silty clay before and after freezing and thawing. The dynamic strength of cement-improved silty clay (CSC) was improved by 2.8 to 5.2 times compared to silty clay, and a high level of dynamic strength can be maintained after multiple freeze-thaw cycles. The dynamic cohesion was increased by 1.5 to 3 times and the dynamic internal friction angle was increased by 1.5 to 4 times. The attenuation rate of the critical dynamic stress of CSC with the number of freeze-thaw cycles was greater than that of the plain filler, while the relative lifting effect of the critical dynamic stress of the cement improvement was significant after three freeze-thaw cycles, and the maximum value was reached at a cycle number of three, with a relative increase of 2.5 times. A new index of critical dynamic stress attenuation of CSC for freeze-thaw cycles was introduced, which provides a useful reference for subgrade improvement and reinforcement along the silty clay railway in northern China. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

19 pages, 5739 KiB  
Article
Static and Dynamic Load Transfer Behaviors of the Composite Foundation Reinforced by the Geosynthetic-Encased Stone Column
by Mengjie Liu, Kaifeng Wang, Jiayong Niu and Fang Ouyang
Sustainability 2023, 15(2), 1108; https://doi.org/10.3390/su15021108 - 06 Jan 2023
Cited by 2 | Viewed by 1359
Abstract
An accurate description of the load transfer behaviors of the geosynthetic-encased stone column (GESC) is of great importance for revealing the bearing capacity of GESC. Static load tests and shake table model tests were performed to characterize the static and dynamic load transfer [...] Read more.
An accurate description of the load transfer behaviors of the geosynthetic-encased stone column (GESC) is of great importance for revealing the bearing capacity of GESC. Static load tests and shake table model tests were performed to characterize the static and dynamic load transfer behaviors of the composite foundation reinforced by the GESC. Under static loading, static load tests were conducted on a fully geosynthetic-encased stone column (FGESC), partially geosynthetic-encased stone column (PGESC) and traditional stone column (TSC). The influence of length and stiffness of the encasement on the stone columns were investigated. Under seismic loading, the shake table model tests were performed to analyze the differences of the dynamic pile-soil stress responses between the composite foundations with the GESC and the TSC. The results show that the static pile-soil stress ratios of the composite foundation with the FGESC are about three to six times of those of the composite foundation with the TSC, and the difference increases with the increase in the stiffness or length of the encasement. The static vertical stress of 60% acting on the pile top can be transferred to the pile bottom for the FGESC, while only 27~45% for the TSC. The dynamic pile-soil stress ratios of the GESC and the TSC first decrease and then increase slightly with the increase of the input peak acceleration. The dynamic pile-soil stress ratio of the GESC is about three times that of the TSC under seismic excitation with the same type and peak acceleration. The attenuation rate of dynamic stress along the pile body under dynamic loading is much faster than that under the static loading. Under the static and dynamic conditions, the load transfer capacity and pile efficacy of the GESC are always better than those of the TSC. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

15 pages, 4839 KiB  
Article
Experiments and Modeling of the Attenuation of the Dynamic Elastic Modulus of Saturated Red Clay under Cyclic Loading
by Hongyan Ma, Yuanlong Zhuang, Liangliang Chen, Mengxi Lv and Song Xu
Sustainability 2023, 15(1), 26; https://doi.org/10.3390/su15010026 - 20 Dec 2022
Cited by 1 | Viewed by 1161
Abstract
Due to the long-term effect of cyclic traffic loads, the accumulated deformation of red clay subgrades is increasing, strength is decreasing, and problems such as uneven settlement are occurring. In order to improve the stability and durability of red clay subgrade, this paper [...] Read more.
Due to the long-term effect of cyclic traffic loads, the accumulated deformation of red clay subgrades is increasing, strength is decreasing, and problems such as uneven settlement are occurring. In order to improve the stability and durability of red clay subgrade, this paper analyzes the effects of cyclic stress ratios and compactness on the development of the dynamic elastic modulus of saturated red clay. This is achieved through dynamic triaxial tests on red clay in the Qingyuan County, Zhejiang Province, China. The results show that the saturated red clay has an attenuation threshold cyclic stress ratio under cyclic loading. The attenuation threshold cyclic stress ratio prediction models were constructed based on the confining pressure and compactness, respectively. By introducing the concept of a relative cyclic stress ratio, the prediction model of the dynamic elastic modulus of saturated red clay (as based on cyclic vibration times and close cyclic stress ratio) is constructed. The model realizes the prediction of the dynamic elastic modulus of red clay under arbitrary cyclic vibration times via the initial cyclic stress ratio, compactness, and other parameters. It provides a theoretical basis for rationally evaluating the dynamic stability of red clay subgrade under cyclic loading. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

26 pages, 10253 KiB  
Article
Influence of Thermal Behavior on the Safety Performance of the Pit Enclosure near Railway Foundations under Solar Radiation
by Wanqi Wang
Sustainability 2022, 14(24), 17001; https://doi.org/10.3390/su142417001 - 19 Dec 2022
Cited by 1 | Viewed by 1254
Abstract
Thermal behavior often affects the performance of thin-walled steel structures and even becomes one of the controlling loads. Steel pipes are often used in foundation pit support. This problem of the thermal stress of steel pipes is very important. The Huhang Railway, a [...] Read more.
Thermal behavior often affects the performance of thin-walled steel structures and even becomes one of the controlling loads. Steel pipes are often used in foundation pit support. This problem of the thermal stress of steel pipes is very important. The Huhang Railway, a section of the high-speed railway from Huzhou to Hangzhou in Zhejiang Province, China, was examined in this study. In this paper, the displacement and stress in pit 358# of the Huhang Railway near the railway foundation was monitored, and a thermal coupling model was established. The temperature field distribution inside the foundation pit was calculated through solar radiation and ambient temperature, and the displacement and stress of the supporting structure and enclosure structure were calculated using the thermal expansion coefficient. The following conclusions were drawn from the comparison: (1) In addition to solar radiation, ambient radiation should also be taken into account at the same time, especially in the calculation of the substructure. (2) The temperature of the support structure was unevenly distributed, and the maximum temperature difference between the steel pipes on the east and west sides could reach from 18.9 °C up to 58.8 °C. The height angle of solar radiation was the main factor that led to this situation. (3) The difference in stress between the support structure and the enclosure structure was positively related to the change in temperature. When the temperature rose, the stress increased, and the horizontal displacement of the enclosure structure decreased, which was beneficial to the stability of the foundation pit and vice versa. (4) The thermal behavior had different effects on the stress at different depths and times, and had spatial and temporal heterogeneity. The enclosure stresses had a certain delay in response to temperature changes. The reasons for this are yet to be investigated. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

18 pages, 4397 KiB  
Article
Spatial–Temporal Characteristics of Freezing/Thawing Index and Permafrost Distribution in Heilongjiang Province, China
by Chengjie Song, Changlei Dai, Yaqi Gao, Chuang Wang, Miao Yu, Weiming Tu, Minghui Jia and Ruotong Li
Sustainability 2022, 14(24), 16899; https://doi.org/10.3390/su142416899 - 16 Dec 2022
Cited by 2 | Viewed by 1609
Abstract
Under the trend of climate warming, the high-latitude permafrost in Heilongjiang Province is becoming seriously degraded. The question of how to quantitatively analyze the spatial and temporal trends of multi-year permafrost has become fundamental for current permafrost research. In this study, the temporal [...] Read more.
Under the trend of climate warming, the high-latitude permafrost in Heilongjiang Province is becoming seriously degraded. The question of how to quantitatively analyze the spatial and temporal trends of multi-year permafrost has become fundamental for current permafrost research. In this study, the temporal and spatial variations of annual mean air temperature (MAAT), annual mean ground temperature (MAGST) and freezing/thawing index based on air and surface temperature data from 34 meteorological stations in Heilongjiang Province from 1971–2019, as well as the variation characteristics of permafrost distribution, were analyzed based on the freezing index model. The results showed that both MAAT and MAGST in Heilongjiang Province tended to decrease with the increase of altitude and latitude. For interannual variation, the MAAT and MAGST warming rates tended to be consistent across Heilongjiang Province, with multi-year variation from −8.64 to 5.60 °C and from −6.52 to 7.58 °C, respectively. From 1971–2019, the mean annual air freezing index (AFI) and ground surface freezing index (GFI) declined at −5.07 °C·d·a−1 and −5.04 °C·d·a−1, respectively, whereas the mean annual air thawing index (ATI) and ground surface thawing index (GTI) were elevated at 7.63 °C·d·a−1 and 11.89 °C·d·a−1, respectively. The spatial distribution of the multiyear mean AFI, ATI, GFI and GTI exhibited a latitudinal trend, whereas the effect of altitude in the northern mountainous areas was greater than that of latitude. Permafrost was primarily discovered in the Daxing’an and Xiaoxing’an Mountains in the north, and sporadically in the central mountainous regions. The southern boundary of permafrost shifted nearly 2° to the north from 1970 to 2010s, while the southern boundary of permafrost in Heilongjiang Province was stable at nearly 51° N. The total area of permafrost narrowed from 1.11 × 105 km2 in the 1970s to 6.53 × 104 km2 in the 2010s. The results of this study take on a critical significance for the analysis of the trend of perennial permafrost degradation at high latitudes in Heilongjiang Province and the whole northeastern China, as well as for mapping the distribution of large areas of permafrost using the freezing index model. This study provides a reference for natural cold resource development, ecological protection, climate change and engineering construction and maintenance in permafrost areas. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

19 pages, 6644 KiB  
Article
A Study on the Train-Induced Vibration Responses of Heavy Haul Railway Subgrade in Seasonally Frozen Regions Using Field Experiments
by Yu-Zhi Zhang, Ya-Qian Dong, Xiu-Xiu Cao and Pei Li
Sustainability 2022, 14(23), 15954; https://doi.org/10.3390/su142315954 - 30 Nov 2022
Cited by 1 | Viewed by 1117
Abstract
The dynamic response resulting from heavy haul train leads to the deterioration of the railway subgrade, especially those built in seasonally frozen regions. In this work, a typical heavy haul railway section in a seasonally frozen region is monitored on-site. The time domain [...] Read more.
The dynamic response resulting from heavy haul train leads to the deterioration of the railway subgrade, especially those built in seasonally frozen regions. In this work, a typical heavy haul railway section in a seasonally frozen region is monitored on-site. The time domain and the frequency domain analysis of the subgrade vertical vibration acceleration, dynamic speed, and displacement during the non-frozen period and the frozen period are investigated. The results show that the vibration response of the subgrade is affected by various factors, including the train type, locomotive, traveling speed, train formation, heavy load, and the prevalent season. Further, it is observed that the maximum and average vertical acceleration of the subgrade, the vibration speed, and the dynamic displacement increase during the frozen period. However, the main frequency of the natural vibration remains significantly higher than that before freezing. Moreover, the frozen soil has a significant amplification effect both on the acceleration and the attenuation rate. Similarly, the subgrade’s vibration mode has a low frequency and high amplitude during the freezing period, and the dynamic response characteristics become increasingly apparent as the axle load increases. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

18 pages, 9341 KiB  
Article
Study on Cyclic Bearing Capacity of Suction Pile Based on Equivalent Cyclic Creep Model
by Kang Huang, Wenbo Zhu, Xin Liu, Zhongyuan Yao, Yu Zhang, Shu Yan, Xiaojiang Guo and Guoliang Dai
Sustainability 2022, 14(22), 15152; https://doi.org/10.3390/su142215152 - 15 Nov 2022
Viewed by 912
Abstract
In the process of cyclic loading, strain development not only presents the strain softening phenomenon, but also a strain hardening phenomenon, depending on the different values of static deflection stress. The strain hardening and strain softening characteristics of soft clay are studied by [...] Read more.
In the process of cyclic loading, strain development not only presents the strain softening phenomenon, but also a strain hardening phenomenon, depending on the different values of static deflection stress. The strain hardening and strain softening characteristics of soft clay are studied by cyclic triaxial tests. The test results show that when the static deflection stress is zero, the value of cyclic cumulative strain is small, and the strain development presents the softening phenomenon. When the static deflection stress is greater than zero, the accumulation strain increases with increasing cyclic deflection stress, and the strain development present strain hardening phenomenon. Therefore, a strain softening index and strain hardening index were proposed to describe the cyclic characteristics of soil. Moreover, an equivalent cyclic creep model was established by considering the strain hardening index to describe cyclic characteristics of suction pile. The results obtained using the proposed method are in reasonably good agreement with the measured results. This can provide a new method for analyzing the cyclic characteristics of soil and the suction pile. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

13 pages, 3686 KiB  
Article
Seismic Spectral Parameters Fitting Analysis of Reservoir Area in Western China
by Zhiren Feng, Bo Jin and Zhuo Zhao
Sustainability 2022, 14(22), 15033; https://doi.org/10.3390/su142215033 - 14 Nov 2022
Viewed by 871
Abstract
In this study, the seismic events (>ML 2.0 earthquake motion records recorded by China earthquake net stations) in Western China are calculated and the source parameters of several hundreds of seismic events are obtained, such as corner frequency fc, [...] Read more.
In this study, the seismic events (>ML 2.0 earthquake motion records recorded by China earthquake net stations) in Western China are calculated and the source parameters of several hundreds of seismic events are obtained, such as corner frequency fc, zero frequency limit Ω0, seismic moment M0, stress drop ∆σ, and apparent stress σapp. The 95% confidence interval of each parameter of each earthquake is obtained. The sample area is about 100 km × 400 km. Then, the calculation results are compared with statistical results, which shows that the correctness and feasibility of the fitting analysis are feasible and correct. Finally, several conclusions and prospects are presented and discussed. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

17 pages, 9556 KiB  
Article
Cyclic and Post-Cyclic Behaviors of Stabilized Sand-Containing Soft Soil in Coastal Areas
by Lingshi An, Xinxin Zhao, Dongwei Li, Liu Yang, Peng Li, Lei Guo and Lina Wang
Sustainability 2022, 14(22), 15017; https://doi.org/10.3390/su142215017 - 14 Nov 2022
Viewed by 1157
Abstract
Land resources are being depleted due to global climate change, and as a result, infrastructures such as expressways and high-speed railways have no option but to be built in soft soil regions. Hence, the cyclic and post-cyclic behaviors of soft soil are vitally [...] Read more.
Land resources are being depleted due to global climate change, and as a result, infrastructures such as expressways and high-speed railways have no option but to be built in soft soil regions. Hence, the cyclic and post-cyclic behaviors of soft soil are vitally important. However, little attention has been devoted to this issue. In the current study, a series of cyclic triaxial tests and standard monotonic loading tests were carried out in order to investigate the cyclic and post-cyclic behavior of stabilized sand-containing soft soil. In addition, the stiffness evolution index model was proposed to describe the characteristics of stiffness evolution. The results show that for a given number of loading cycles, stiffness almost linearly decreases with the increase in sand content. The higher the confining pressure is, the greater the stiffness is. The cement content has the greatest impact on the stiffness evolution index. The stiffness evolution index model can provide a good description of experimental data. The initial value of post-cyclic axial strain is non-zero due to the accumulative strain caused by previous cyclic loading. Post-cyclic stress increases rapidly within a small range of strain and can reach peak stress with great speed. The post-cyclic initial tangent modulus increases from 1602 kPa to 4803 kPa as the cement content increases from 6% to 12%. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

14 pages, 4979 KiB  
Article
Accumulative Strain of Sand-Containing Soft Soil Reinforced by Cement and Sodium Silicate under Traffic Loading
by Lingshi An, Junhao Chen, Dongwei Li, Peng Li, Lei Guo and Guanren Chen
Sustainability 2022, 14(21), 14127; https://doi.org/10.3390/su142114127 - 29 Oct 2022
Cited by 2 | Viewed by 853
Abstract
The accumulative strain of sand-containing soft soil is crucial to the stability of the construction of embankment engineering such as expressways and high-speed railways. However, little attention has been devoted to the accumulative strain of sand-containing soft soil. In the current study, a [...] Read more.
The accumulative strain of sand-containing soft soil is crucial to the stability of the construction of embankment engineering such as expressways and high-speed railways. However, little attention has been devoted to the accumulative strain of sand-containing soft soil. In the current study, a series of cyclic triaxial tests were performed to investigate the accumulative strain of sand-containing soft soil reinforced by cement and sodium silicate under traffic loading. In addition, the accumulative strain model was proposed to describe the characteristic of accumulative strain. The results show that for the specimens with a high sand content (25%, 30%, and 35%), the accumulative strain increases obviously with the increase of the sand content. For the specimen with a cement content of 3%, the accumulative strain increases distinctly with the increasing loading time. The accumulative strain is strongly influenced by confining pressure. When the repeated cyclic stress amplitude is greater than 0.17 kN, the increase rate of accumulative strain is greater. The shorter the curing time is, the greater the accumulative strain is. The calculated results of the accumulative strain model show a good agreement with test data. Hence, the accumulative strain model can better describe the characteristic of accumulative strain. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

20 pages, 7815 KiB  
Article
Resilient and Sustainability Analysis of Flexible Supporting Structure of Expansive Soil Slope
by Rui Zhang, Panxuan Tang, Tian Lan, Zhaojing Liu and Shiguang Ling
Sustainability 2022, 14(19), 12813; https://doi.org/10.3390/su141912813 - 08 Oct 2022
Cited by 6 | Viewed by 1223
Abstract
In order to improve the ability of the flexible support structure to resist, recover and adapt to the failure of expansive soil slope, it is necessary to analyze and study its structural resilience systematically. Based on the long-term field monitoring test of expansive [...] Read more.
In order to improve the ability of the flexible support structure to resist, recover and adapt to the failure of expansive soil slope, it is necessary to analyze and study its structural resilience systematically. Based on the long-term field monitoring test of expansive soil slope with flexible support along the south line of the Guinan key project, combined with the whole life cycle assessment (LCA), this paper discusses the theory and method of resilient design of expansive soil slope with a flexible support structure. The results show that the variation trend of geogrid strain is basically consistent with that of soil pressure at the side of the slope. It increases gradually with the increase in rainfall in the rainy season. When the rainfall decreases significantly in the dry season, the geogrid will shrink accordingly to realize the periodic regulation of lateral deformation of expansive soil. The life cycle assessment analysis shows that the carbon emission of the flexible support structure is 10% of that of the rigid support structure, and the resource and energy consumption of the flexible support structure is about 50% lower than that of the rigid support structure. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

20 pages, 5805 KiB  
Article
Settlement Characteristic of Warm Permafrost Embankment with Two-Phase Closed Thermosyphons in Daxing’anling Mountains Region
by Guanfu Wang, Jiajun Bi, Youkai Fan, Long Zhu, Feng Zhang and Decheng Feng
Sustainability 2022, 14(19), 12272; https://doi.org/10.3390/su141912272 - 27 Sep 2022
Cited by 3 | Viewed by 999
Abstract
The Xing’anling Mountains are the second largest permafrost region in China. One of the important issues for highways in these regions is how to control the settlement during the operation period to meet the demand of road stability. This paper selects a typical [...] Read more.
The Xing’anling Mountains are the second largest permafrost region in China. One of the important issues for highways in these regions is how to control the settlement during the operation period to meet the demand of road stability. This paper selects a typical permafrost embankment in the Daxing’anling Mountains permafrost region, presents the finite element models of the embankment, and verifies it using field monitoring data to study the thermal and deformation characteristics within 50 years after construction. Calculation results illustrate that the permafrost under the embankment has degraded significantly during the operation period of the highway and led to serious settlement. To prevent the degradation of permafrost, a series of models with two-phase closed thermosyphons (TPCTs) were established to analyze the cooling effect. The contribution of different factors, including install locations, depth, and shapes of the TPCTs, were assessed on their effects on cooling the permafrost and reducing the embankment settlement. Results show that the TPCTs have an excellent cooling effect on the permafrost embankment. However, as the TPCTs change the temperature distribution of the embankment, they will inevitably cause differential settlement. In order to ensure the cooling effect and reduce the differential settlement of the embankment, it is suggested that L-shaped TPCTs should be adopted in the remedial engineering. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

22 pages, 9546 KiB  
Article
Study on Anti-Uplift Effect of Micro-Steel-Pipe Pile on Red-Bedded Soft Rock Subgrade
by Rui Zhang, Hui Luo, Zhengnan Liu and Rusong Nie
Sustainability 2022, 14(19), 11923; https://doi.org/10.3390/su141911923 - 21 Sep 2022
Cited by 3 | Viewed by 1216
Abstract
To investigate the treatment effect of micro-piles on uplift deformation of red-bedded soft rock subgrade, an in-situ static load test of slurry injected steel pipe micro-piles with different length was carried out, the uplift bearing capacity and deformation characteristics of micro-piles were analyzed, [...] Read more.
To investigate the treatment effect of micro-piles on uplift deformation of red-bedded soft rock subgrade, an in-situ static load test of slurry injected steel pipe micro-piles with different length was carried out, the uplift bearing capacity and deformation characteristics of micro-piles were analyzed, and the load transfer function of pile lateral friction resistance was modified with the consideration of pile length. A numerical simulation method considering the variable shear stiffness at the pile-soil interface was established, and the inversion of the relevant material parameters was carried out based on the in-situ test results. Through numerical simulation, the effect of single piles with different pile lengths and group piles with different pile spacing on the treatment of the uplift deformation of the subgrade was investigated. Finally, the anti-uplift design method of micro-piles in red-bedded soft rock was proposed. The results show that the uplift bearing capacity increased nonlinearly with the increase in pile length, and the variation curve of pile lateral friction resistance with pile-soil relative displacement showed a hardened type. The predicted pile lateral friction resistance shows a good correlation with the measured result; all the correlation coefficients were greater than 0.81. The uplift deformation of subgrade without piles was radially distributed with the maximum value of 5.12 mm as the center. A single micro-pile with a length of 7 m or a rectangular array of group piles with a length of 7 m and a spacing of 3D could effectively decrease the maximum uplift deformation to less than 4.0 mm, which can meet the requirement of specification. Thus, the micro-piles could be used for controlling the uplift deformation of red-bedded soft rock subgrade, and this study can provide a reference for anti-uplift design in the distributed area of red-bedded soft rock. Full article
(This article belongs to the Special Issue Enhancing Subgrade Stability in Complex Environment for Sustainable Road)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-18
Back to TopTop