Seepage is one of the main causes for the deformation and instability of canal slopes in Xinjiang,China.In this study,centrifugal model tests under wetting-drying(WD)and wetting-drying-freezing-thawing(WDFT)cycles wer...Seepage is one of the main causes for the deformation and instability of canal slopes in Xinjiang,China.In this study,centrifugal model tests under wetting-drying(WD)and wetting-drying-freezing-thawing(WDFT)cycles were performed to investigate the water infiltration characteristics below a canal.The results show that the shallow soil of the canal models was fully saturated in the wetting process.Compared with the canal model under the WD cycles,the canal model under the WDFT cycles had larger saturated areas and a higher degree of saturation below the canal top after each cycle,indicating that the freezing-thawing(FT)process in the WDFT cycles promoted the water infiltration behavior below the canal slope.The cracks on the surface of the canal model under the cyclic action of WDFT developed further and had a higher connectivity,which provided the conditions for slope instability from a transverse tensile crack running through the canal top.On this basis,a field test was conducted to understand the water infiltration distribution below a typical canal in Xinjiang,China,which also verified the accuracy of the centrifugal results.This study provides a preliminary basis for the maintenance and seepage treatment of canals in Xinjiang,China.展开更多
The iron concentrations of snows,semi-melting snows,snowmelts,and ditch waters were observed in four typical microhabitats,Carex lasiocarpa marsh(Ⅰ), Calamagrostis angustifolia wet meadow(Ⅱ),dry land (Ⅲ)and paddy f...The iron concentrations of snows,semi-melting snows,snowmelts,and ditch waters were observed in four typical microhabitats,Carex lasiocarpa marsh(Ⅰ), Calamagrostis angustifolia wet meadow(Ⅱ),dry land (Ⅲ)and paddy field(Ⅳ),of Sanjiang Plain Wetland, Northeast China.Each sample was collected from three sites of one microhabitat,mixed together, filtrated with 0.45μm membrane,and tested using atomic absorption spectrometry(AAS)for iron measurement.The iron concentrations of soil solutions were investigated as well.Each soil solution was in-situ extracted by negative pressure,filtrated with 0.45μm membrane,and tested using AAS,too. The results showed that the wet precipitation of iron from snow were little to detect.The loss of iron was attributed to the interaction of water and soil surface. The iron concentrations of snowmelts were 7.4,15,展开更多
To reveal the influencing factors and changing rules for the hydrothermal interaction process of highway subgrade, the field measurements of Shiwei-Labudalin Highway in Inner Mongolia, China was conducted for 3 years,...To reveal the influencing factors and changing rules for the hydrothermal interaction process of highway subgrade, the field measurements of Shiwei-Labudalin Highway in Inner Mongolia, China was conducted for 3 years, based on which the freezing-thawing rules and water content changing characteristics were analyzed. The main results show the subgrade presents a frequent freezing-thawing alternation, and the water content of subgrade exhibits an obvious seasonal alternation. The subbase has the maximum water content, while the base has the minimum water content. The change of water flux is concentrated in the thawing period and consistent with the change of temperature gradient. The subbase layer has the most active water flux due to the heat absorption and impermeability of pavement that easily causes the water accumulation in this layer. Therefore, the prevention and treatment for the freezing-thawing disease should be started from heat insulation and water resistance.展开更多
基金Project(2017YFC0405100)supported by the National Key Research and Development Program of ChinaProjects(51879166,51709185,51909170)supported by the National Natural Science Foundation of China+1 种基金Project(SKLFSE201909)supported by the Open Research Fund Program of State Key Laboratory of Permafrost Engineering,ChinaProject(2018M640500)supported by Postdoctoral Science Foundation of China。
文摘Seepage is one of the main causes for the deformation and instability of canal slopes in Xinjiang,China.In this study,centrifugal model tests under wetting-drying(WD)and wetting-drying-freezing-thawing(WDFT)cycles were performed to investigate the water infiltration characteristics below a canal.The results show that the shallow soil of the canal models was fully saturated in the wetting process.Compared with the canal model under the WD cycles,the canal model under the WDFT cycles had larger saturated areas and a higher degree of saturation below the canal top after each cycle,indicating that the freezing-thawing(FT)process in the WDFT cycles promoted the water infiltration behavior below the canal slope.The cracks on the surface of the canal model under the cyclic action of WDFT developed further and had a higher connectivity,which provided the conditions for slope instability from a transverse tensile crack running through the canal top.On this basis,a field test was conducted to understand the water infiltration distribution below a typical canal in Xinjiang,China,which also verified the accuracy of the centrifugal results.This study provides a preliminary basis for the maintenance and seepage treatment of canals in Xinjiang,China.
文摘The iron concentrations of snows,semi-melting snows,snowmelts,and ditch waters were observed in four typical microhabitats,Carex lasiocarpa marsh(Ⅰ), Calamagrostis angustifolia wet meadow(Ⅱ),dry land (Ⅲ)and paddy field(Ⅳ),of Sanjiang Plain Wetland, Northeast China.Each sample was collected from three sites of one microhabitat,mixed together, filtrated with 0.45μm membrane,and tested using atomic absorption spectrometry(AAS)for iron measurement.The iron concentrations of soil solutions were investigated as well.Each soil solution was in-situ extracted by negative pressure,filtrated with 0.45μm membrane,and tested using AAS,too. The results showed that the wet precipitation of iron from snow were little to detect.The loss of iron was attributed to the interaction of water and soil surface. The iron concentrations of snowmelts were 7.4,15,
基金Project(2018-MSI-018) supported by the Key Science and Technology Project of the Ministry of Transport of ChinaProject(NJ-2018-28) supported by the Construction Science and Technology of the Department of Transport of Inner Mongolia Autonomous Region of China+2 种基金Project(2019MS05029) supported by the Natural Science Fund Project of Inner Mongolia Autonomous Region of ChinaProject(2020MS05077) supported by the Natural Science Fund Project of Inner Mongolia Autonomous Region of ChinaProject(NJ-2020-05) supported by the Research on Complete Survey Technology of Highway Road Area in High-latitude Permafrost Region, China。
文摘To reveal the influencing factors and changing rules for the hydrothermal interaction process of highway subgrade, the field measurements of Shiwei-Labudalin Highway in Inner Mongolia, China was conducted for 3 years, based on which the freezing-thawing rules and water content changing characteristics were analyzed. The main results show the subgrade presents a frequent freezing-thawing alternation, and the water content of subgrade exhibits an obvious seasonal alternation. The subbase has the maximum water content, while the base has the minimum water content. The change of water flux is concentrated in the thawing period and consistent with the change of temperature gradient. The subbase layer has the most active water flux due to the heat absorption and impermeability of pavement that easily causes the water accumulation in this layer. Therefore, the prevention and treatment for the freezing-thawing disease should be started from heat insulation and water resistance.
