Research On Rapid Determination Technology Of Ion Content And Salinization Degree Of Different Saline Soil In Xinjiang

The conventional soluble salt test is time-consuming,time-consuming,time-consuming,and the cost of judgment is high.Due to the arid climate,less rain and strong evaporation in Xinjiang,the saline soil is widely distributed in this area and has many types.The amount and type of soluble salt will change the basic engineering properties of soil,and directly harm the above factors,such as leaching and collapsing,boiling,salt swelling,soil erosion,soil erosion and so on Corrosion,and often not recoverable.According to the technical code for design and construction of highway subgrade and pavement in saline soil area of Xinjiang,whether saline soil can be used as subgrade filler is determined by both Cl^-/SO₄^2-and total salt content.In recent years,with the large-scale development of national road projects in Xinjiang,the workload of soluble salt analysis of subgrade filling will increase.According to the specification"highway geotechnical test specification",the content of soluble total salt and the content of various ions can be accurately determined,and then according to the"technical specification for design and construction of highway subgrade and pavement in saline soil areas in Xinjiang",the type of saline soil can be determined,However,the operation process of the test method is not only cumbersome and time-consuming,but also not suitable for rapid detection of large quantities of soil samples on site.The laboratory conditions of the construction unit are relatively poor compared with the urban area,and can not meet the needs of rapid determination of large quantities of soil samples.In order to quickly determine the type and degree of salinization of saline soil in Xinjiang,and make it enter the construction site to follow up and detect the content of soluble salt in soil in real time,this paper carries out experimental research on the subgrade soil of Balikun Mulei section of Beijing Xinjiang expressway.Based on the spectrophotometric method,Cl^-/SO₄^2-was determined by rapid chloride and sulfate analyzer to determine the type of saline soil.According to the principle of salt solution conductivity,the relationship between total salt content and conductivity of each type of saline soil was established.The results show that the relative error between the content of Cl^-,SO₄^2-in the soil extract and the actual value can be controlled within 5%and 4%respectively by using the rapid tester.The best temperature for measuring the conductivity of soil extract is 15℃～25℃,the best soil quality is 100g,the best soil water ratio is 1:5,the same soil sample,The relative error of the unfiltered conductivity of drying is slightly lower than that of drying filtration,and the more Na Cl content is,the greater the conductivity is,the more the total salt content of unknown and known salt soil type is significantly related to the conductivity.The relationship between the total salt content and conductivity of known salt soil type is were all higher than 0.99.The relationship between total salt content and conductivity of unknown salt soil type,regression coefficient R² It is 0.992.The method is convenient and fast.Through the test of subgrade soil engineering of Beijing Xinxin high speed Balikun Mulei section project,the error does not affect the determination of the type and salinization degree of the salt soil in the road engineering,but the soil source should be used carefully at the critical point.