A test apparatus used to simulate the dual effects of freeze-thaw and dynamic load on subgrade in cold regions
Introduction
Subgrade diseases and building foundation diseases caused by freezing and thawing are common engineering problems in geotechnical engineering in cold regions. (Zhang et al., 2019a; Wu et al., 2018; Zhu et al., 2010; Niu et al., 2020). In cold regions, the subgrade is not only affected by freezing and thawing process, but also subjected to the dynamic load of vehicles. Therefore, the dual effect of freezing and thawing and load will increase the incidence of subgrade disease. (Xiao et al., 2015).
In order to study the stability of subgrade under freeze-thaw and dynamic load, scholars have carried out a large number of model tests. Some scholars studied the subgrade by establishing mathematical models (Zhang et al., 2021, Zhang et al., 2022; Zhang, 2012), and others studied it by establishing large-scale physical indoor model tests (Mao et al., 2004). After researching the literature, we found that many physical model experimental studies have different concerns. Some physical model tests only focus on the hydrothermal change of the subgrade under the action of freezing and thawing, while ignoring the problem of traffic dynamic load (Zhu, 1987; Bing, 2008; Yu et al., 2002; Liu et al., 2019; Zhang et al., 2019b; Yang et al., 2020). Others consider freeze-thaw and static load issues, but the apparatus has no dynamic load capability (Chang et al., 2011; Li et al., 2019; Mao et al., 2012; Wang et al., 2022). With the increasing systematic requirements for physical model tests, a multifunctional freeze-thaw test system (open system) was developed (Zhao et al., 2020). The test system is used to simulate the freezing and thawing cycle process of subgrade soil in natural environment, and can apply dynamic load, but its single-point dynamic load application process cannot completely simulate the real traffic dynamic load process. The cold regions engineering dynamic load model test system designed by Zhao et al., 2011 also cannot fully simulate the real traffic dynamic load process. Ma et al. (2017) independently designed and developed the soil frost heave test system. The frost heave test system can simulate the working state of subgrade in natural environment, which controls the test condition from loading mode of temperature and overburden, and water supply and lateral constraints, but the function of traffic dynamic load is still not fully realized.
To sum up, the physical model test of subgrade stability has undergone a long period of development, design and research. From simple hydrothermal and dynamic loads, to the combined action of hydrothermal, static loads and single-point dynamic loads, its functions are constantly being improved and developed. In order to promote the research on the stability of subgrade under the dual effects of freeze-thaw and dynamic load, a test apparatus used to simulate the dual effects of freeze-thaw and dynamic load on subgrade in cold regions has been developed, which can simulate subgrade damage in permafrost and seasonally frozen regions. The apparatus can simulate the dual effects of freeze-thaw and traffic dynamic load, and on this basis, it can realize the monitoring functions of temperature, water, pore pressure and deformation.
Section snippets
Apparatus description
As shown in Fig. 1, the apparatus is mainly composed of three parts: loading system, environmental simulation system and data acquisition system. The loading system is mainly used to apply dynamic load to the subgrade. The environment simulation system can simulate the site environment. The data acquisition system collects the data (Temperature, Water, Pore Water pressure, Displacement) changes of subgrade under the dual effects of freeze-thaw and load.
Apparatus can simulate the situation
The freeze-thaw and dynamic load mode can simulate the changes of highway and railway subgrade when subjected to freeze-thaw and dynamic load. According to the different dynamic load forms of the subgrade (trains, trucks, cars), the width of the thin steel plate of the apparatus and the load stress can be adjusted to simulate different load situations.
Some test results with this apparatus
In order to verify the performance of the apparatus, the highway subgrade under the dual effects of freeze-thaw and dynamic load was studied. Among the road vehicles, heavy trucks are the most likely to cause subgrade damage, so heavy trucks are selected as the research object. Next, the highway subgrade of Lanzhou is selected as the test object for research. The water, temperature, pore water pressure and deformation of soil at the cut-fill transition zone of subgrade are studied. The soil
Summary
A freeze-thaw and dynamic load apparatus for subgrade in permafrost and seasonal permafrost regions was developed. The apparatus consists of loading system, environment simulation system and data acquisition system. The apparatus has the following characteristics: 1) Freeze-thaw and dynamic load were applied to the subgrade; 2) The failure law of subgrade under freeze-thaw and dynamic load can be studied;3) The influence of different vehicle (train, car) loads on subgrade can be studied.
In
CRediT authorship contribution statement
Linzhen Yang: Writing – review & editing, Investigation, Visualization. Jinbang Zhai: Data curation, Writing – original draft. Ze Zhang: Conceptualization, Methodology, Project administration, Funding acquisition. Andrey Melnikov: Supervision, Validation, Funding acquisition. Doudou Jin: Supervision, Formal analysis, Software.
Declaration of Competing Interest
We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled, “A test apparatus used to simulate the dual effects of freeze-thaw and dynamic load on subgrade in cold regions”.
Acknowledgement
The authors greatly appreciate the support by the following research grants: (a) Heilongjiang Transportation Investment Group Co., Ltd (JT-100000-ZC-FW-2021-0129), (b) the National Natural Science Foundation of China (NSFC) (41771078, 42011530083), (c) the Fundamental Research Funds for the Central Universities (2572021AW36), (d) Russian Foundation for Basic Research: RFBR-NSFC project (20-55-53006).
References (22)
- et al.
Influence from overlying load on law of water-salt migration and deformation of salinized soil under effect of freeze-thaw cycle
Water Resour Hydropower Eng.
(2022) - et al.
Delamination frost heave in embankment of high-speed railway in high altitude and seasonal frozen region
Cold Reg. Sci. Technol.
(2018) - et al.
Large-scale model testing of high-speed railway subgrade under freeze-thaw and precipitation conditions
Adv. Civ. Eng.
(2019) - et al.
Effects of freeze-thaw on the water-heat process in a loess subgrade over a cut-fill transition zone by laboratory investigation
Cold Reg. Sci. Technol.
(2019) - et al.
Liquid water–vapour migration tracing and characteristics of unsaturated coarse-grained soil in high-speed railway subjected to freezing and different load types
Constr. Build. Mater.
(2021) - et al.
Macro- and mesoscopic experimental study of the effects of water content on moisture migration in coarse-grained fillings under freeze–thaw cycles and loads
Cold Reg. Sci. Technol.
(2022) - et al.
Experimental investigation on the train-induced subsidence prediction model of Beiluhe permafrost subgrade along the Qinghai-Tibet Railway in China
Cold Reg. Sci. Technol.
(2010) Study on Failure Mechanism of Roadbed with Salty Soil during Cyclical Freezing and Thawing
(2008)- et al.
Simulation experiment of dynamic responses of high temperature frozen subgrade to dynamic loading
J. Chin. Railway Soc.
(2011) - et al.
Water migration and deformation during freeze-thaw of crushed rock layer in chinese high-speed railway subgrade: large scale experiments
Cold Reg. Sci. Technol.
(2019)
Mechanism of groundwater migration in the subgrade in a seasonally frozen soil area
J. Cold Reg. Eng.
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These authors contributed equally to this work and should be considered co-first authors.