Research On The Treatment Effect Of Water And Salt Isolation Measures For Saline Soil Roadbeds In Qinghai

When constructing roadbeds in saline soil areas,it is easy to cause diseases such as salt heaving,frost heaving,and thawing,which have extremely adverse effects on the stability of the roadbed and the durability of the road surface.Therefore,it is extremely necessary to study the treatment measures for roadbeds in saline soil areas.This article relies on the saline soil roadbed test section of the Qinghai Laomangya to Asbestos Mine highway,and adopts measures such as laying a long wire woven two cloth and one film partition layer,combining partition layers,and setting a high fill roadbed to treat the roadbed.Combined with indoor experiments,on-site monitoring,and numerical simulation methods,in-depth research is conducted on the distribution of temperature,water,salt,and displacement fields in the roadbed,and a series of research results have been achieved.1.The basic physical properties of the test section roadbed were determined through indoor experiments,and the conclusion was drawn that K19+180,K38+050,and K46+300 sections are medium salt,weak salt,and non salt sections,respectively.The salt content is mainly sulfate,and the soil particles are coarse and are gravel sand soil.2.By using on-site monitoring methods,the temperature,salinity,and displacement changes of the test section were monitored for a long time.The conclusion was drawn that after laying two woven fabrics and a membrane with a combination of a long filament machine and a partition layer,the salinity would be blocked below the partition layer,indicating that setting a partition layer can effectively block the rise and migration of salinity.3.The four-field coupling theory was developed using COMSOL Physics,and the temperature,water,salt,and displacement fields under actual operating conditions were calculated.The results were compared with on-site monitoring values,and the conclusion was drawn that the temperature and salt values calculated using the four-field coupling theory were similar to the measured errors,while the displacement values were slightly smaller due to only considering frost heave.4.By changing the position and thickness of the partition layer,as well as the height of the roadbed filling,different comparative working conditions were established.The temperature field,water field,salt field,and displacement field were calculated.From the perspectives of salt resistance,water resistance,frost prevention,and prevention of secondary salinization,it was concluded that the optimal laying position for the long wire woven two cloth and one film partition layer is 0.5m above the roadbed height The optimal thickness for the combination partition layer is 50 cm and the optimal filling height for high fill subgrade is 5m.