Research in Cold and Arid Regions最新文献

{"title":"Thermal-hydro-mechanical coupled analysis of unsaturated frost susceptible soils","authors":"YuWei Wu ,&nbsp;Tatsuya Ishikawa","doi":"10.1016/j.rcar.2022.08.002","DOIUrl":"10.1016/j.rcar.2022.08.002","url":null,"abstract":"<div><p>Damage caused by frost heave leads to costly maintenance in cold regions, like Hokkaido, Japan. Therefore, the study of the frost mechanism with experimental and numerical methods has been of great interest. Numerous models have been developed to describe the freezing process of saturated soil, which differs from the partially saturated conditions in the field. In fact, most subsurface soils are unsaturated. The freezing process of partially saturated soils is more complex than saturated soils, as the governing equations show strongly nonlinear characteristics. This study proposes a thermo-hydro-mechanical coupled model considering the heat transfer, water infiltration, and deformation of partially saturated soil to reproduce the freezing process of partially saturated frost susceptible soils distributed in Hokkaido. This model better considers the water-ice phase change and soil freezing characteristic curve (SFCC) during freezing under field conditions. The results from the multiphysics simulations agree well with the frost heave and water migration data from frost heave tests of Touryo soil and Fujinomori soil. In addition, this study discussed the influence of the various factors on frost heave amount, including temperature gradients, overburden pressures, water supply conditions, cooling rates, and initial saturation. The simulation results indicate that the frost heave ratio is proportional to the initial degree of saturation and is inversely proportional to the cooling rate and overburden pressure.</p><p>Moreover, simulation under the open system generates much more frost heave than under the closed system. Finally, the main features of the proposed model are revealed by simulating a closed-system frost heave test. The simulation results indicate that the proposed model adequately captures the coupling characteristics of water and ice redistribution, temperature development, hydraulic conductivity, and suction in the freezing process. Together with the decreased hydraulic conductivity, the increased suction controls the water flow in the freezing zone. The inflow water driven by cryogenic suction gradient feeds the ice formation, leads to a rapid increase in total water content, expanding the voids that exceed the initial porosity and contributing to the frost heave.</p></div>","PeriodicalId":53163,"journal":{"name":"Research in Cold and Arid Regions","volume":"14 4","pages":"Pages 223-234"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2097158322000027/pdfft?md5=86876079d12ddf8509e85aaa3b54d784&pid=1-s2.0-S2097158322000027-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42325952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of automated cone penetrometer for railway investigation using correlations with DCPI and deflection modulus","authors":"Sang Yeob Kim ,&nbsp;Won-Taek Hong ,&nbsp;Jong-Sub Lee","doi":"10.1016/j.rcar.2022.08.005","DOIUrl":"10.1016/j.rcar.2022.08.005","url":null,"abstract":"<div><p>Portable in-situ devices have been used for characterizing low accessible field, such as the railway subgrade. In this study, the automated cone penetrometer (ACP) was designed for the application on the railway subgrade. ACP is composed of the cone tip, driving rod, and hydraulic hammer system. The hydraulic motor lifts and drops the 294.3 N hammer from a height of 200 mm such that the potential energy of 58.9 N m impacts the driving rod. The <em>N</em>-value (<em>N</em>_ACP) from the ACP test was compared with the dynamic cone penetration index (DCPI) from the dynamic cone penetrometer (DCP) test. The test results show that the <em>N</em>_ACP and DCPI profiles show opposite trend owing to the inverse concept of the unit. From the correlation of DCPI and <em>N</em>_ACP, the limitation of DCPI reveals owing the minimum manually measured value of 1 mm/blow. Additionally, the evaluation of the deflection modulus (<em>E</em>_FWD) using <em>N</em>_ACP is more efficient than that using DCPI. Based on the result of this study, we suggest that ACP can be used for strength and stiffness evaluation of railway subgrade rapidly and reliably.</p></div>","PeriodicalId":53163,"journal":{"name":"Research in Cold and Arid Regions","volume":"14 4","pages":"Pages 235-238"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2097158322000052/pdfft?md5=5edf32620562fcae100923220f2ead78&pid=1-s2.0-S2097158322000052-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44963456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Frozen curtain characteristics during excavation of submerged shallow tunnel using Freeze-Sealing Pipe-Roof method","authors":"Ye Niu ,&nbsp;ZeQun Hong ,&nbsp;Jun Zhang ,&nbsp;Lei Han","doi":"10.1016/j.rcar.2022.08.003","DOIUrl":"10.1016/j.rcar.2022.08.003","url":null,"abstract":"<div><p>The Freeze<strong>-</strong>Sealing Pipe-Roof (FSPR) method, which has been applied for the first time in the Gongbei Tunnel of the Hong Kong<strong>-</strong>Zhuhai<strong>-</strong>Macao Bridge, is a new approach of tunnel pre<strong>-</strong>support that allows flexible adjustment of freeze tube arrangement and can be adapted to different environmental conditions. When the FSPR method is used to construct shallow burial submerged tunnels, the frozen wall to hold back groundwater during excavation will be weakened by air and water flows inside and outside the tunnel, and its waterproof performance needs to be further investigated. In this paper, a two-dimensional numerical model of the temperature field considering excavation and moving water boundary is established based on the preliminary design scheme and in-situ conditions and is used to analyze the variation in frozen curtain properties with various active freezing times during excavation. The results show that excavation has a weakening effect on both sides of the frozen wall, with a greater effect on the inner side, and a positive temperature appears in the local area inside the jacked pipe. The concrete fill in the jacked pipe obviously improves the freezing efficiency, and the tunnel excavation after 60 days of active freezing in the interval filling mode can ensure that the frozen soil thickness at the thinnest segment exceeds 2 m, <em>i.e.</em>, the design requirement. In practice, the active freezing time can be extended appropriately to reduce the influence of river water flow above the tunnel. The study serves as a technical reference for the design and implementation of similar projects.</p></div>","PeriodicalId":53163,"journal":{"name":"Research in Cold and Arid Regions","volume":"14 4","pages":"Pages 267-273"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2097158322000039/pdfft?md5=0c5510f5a19c7d420ca19c1a1f0a3193&pid=1-s2.0-S2097158322000039-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42339285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Triaxial test on glass beads simulating coarse-grained soil","authors":"WenDong Xu ,&nbsp;XueFeng Li ,&nbsp;WenWei Yang ,&nbsp;HongJin Jia","doi":"10.1016/j.rcar.2022.10.001","DOIUrl":"10.1016/j.rcar.2022.10.001","url":null,"abstract":"<div><p>It is feasible to study the mechanical characteristics of coarse-grained soil by simulated granular materials such as glass beads. In this paper, 3 mm diameter glass beads are used to conduct drained and undrained triaxial tests under different confining pressures to explore their strength, deformation and critical state characteristics. Specifically, the influence of drainage and confining pressure on the stick-slip phenomenon of glass beads is reported. The experimental findings from triaxial tests show that the stress-strain relationship of glass beads softens when the confining pressure is high. Under the undrained condition, the initial modulus increases with the increase in the confining pressure. In contrast, it is not significantly affected by the confining pressure in the drained condition. It is quite evident that the glass beads hardly contract during the shearing process, and their stress path is approximately a segmented straight line. The slope of the critical state line under the undrained condition is greater than that under the drained condition, and the friction angle of the glass beads under the undrained and drained conditions is calculated to be 28.1° and 29.5°, respectively. The phenomenon of stick-slip has been depicted for the different test conditions, and the stick-slip amplitude linearly increases with the confining pressure, especially in the undrained condition. It is also found that the maximum energy released from the phenomenon of stick-slip increases linearly with the confining pressure.</p></div>","PeriodicalId":53163,"journal":{"name":"Research in Cold and Arid Regions","volume":"14 4","pages":"Pages 274-280"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2097158322000131/pdfft?md5=bcab630d03ebf4c3fcf77777bbaccd24&pid=1-s2.0-S2097158322000131-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44489125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discussion on pile axial load test methods and their applicability in cold regions","authors":"JiaWei Gao ,&nbsp;Ji Chen ,&nbsp;Xin Hou ,&nbsp;QiHang Mei ,&nbsp;YongHeng Liu","doi":"10.1016/j.rcar.2022.08.004","DOIUrl":"10.1016/j.rcar.2022.08.004","url":null,"abstract":"<div><p>The measurement of pile axial load is of great significance to determining pile foundation design parameters such as skin friction and end bearing capacity and analyzing load transfer mechanisms. Affected by the temperature and ice content of frozen ground, the interface contact relationship between pile foundation and frozen soil is complicated, making pile axial load measurements more uncertain than that in non-frozen ground. Therefore, it is necessary to gain an in-depth understanding of the current pile axial load test methods. Four methods are systematically reviewed: vibrating wire sensors, strain gauges, sliding micrometers, and optical fiber strain sensors. At the same time, the applicability of the four test methods in frozen soil regions is discussed in detail. The first two methods are mature and commonly used. The sliding micrometer is only suitable for short-term measurement. While the Fiber Bragg grating (FBG) strain gauge meets the monitoring requirements, the Brillouin optical time-domain reflectometer (BOTDR) needs further verification. This paper aims to provide a technical reference for selecting and applying different methods in the pile axial load test for the stability study and bearing capacity assessment of pile foundations in cold regions.</p></div>","PeriodicalId":53163,"journal":{"name":"Research in Cold and Arid Regions","volume":"14 4","pages":"Pages 239-249"},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2097158322000040/pdfft?md5=d0065e18d9524c377fffd202966ecc47&pid=1-s2.0-S2097158322000040-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49201228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}