Application Research On Aeolian Sand Replacement Technique For Saline Soil Foundation Of The Segment Aobu G314 In Xinjiang

With high-speed development of the highway construction in the western China,it is difficult to avoid the special soil area,such as saline soil etc.,affected by the complex factors of geological conditions,meteorological environment and engineering cost etc.,which causing larger difficulties for highway construction.For this reason,the thesis will base on the construction engineering of the Segment Aoyitake to Bulunkou of Xinjiang G314 line to carry out a research on the technologies of saline soil foundation treatment.Firstly,the thesis carried out the geological conditions of the project in the field,and summarized the special foundation distribution section of the project.Secondly,the theis carried out the physical characteristics,modulus of resilience,compression,CBR test,modulus of resilience etc.of the wind-blown sand samples,and did a system study of the technical features of the aeolian sand,the results showed that degree of aeolian sand is uniform,the optimum water content is 13%,the value of the maximum dry density of 1.70 g/cm3,the wind-blown had good flexibility under certain pressure,the compression modulus was higher than the general soil,and it had a certain ability to resist damage..Thirdly,the thesis researched on the method and construction technology of wind deposition in the section of the G314 line of Aobu in Xinjiang.Through comprehensive comparison,roads with severe salinization in this project,puts forward the aeolian sand in filling + foundation treatment scheme of geotextile partition,namely remove surface layer thickness of saline soil and the compaction,wind-blown sand backfill,the subgrade in the middle of road bed top set two cloth a membrane composite geotextile make fault isolation,block the capillary water carrying salt rise.Finally,the thesisi did the field subsidence monitoring for the highway subgrade which was treated by wind-blown sand,found that the maximum daily settlement was 2 mm per day of the monitoring sections,the edge pile's maximum displacement rate less than 2 mm per day,the settlement curve without abnormal fluctuations,it presented obviously convergent;And the deeper it is,the longer it will be stable.It is suggested that when designing,it is possible to make the preloading of the section of the filling as much as possible.Based on the observations,the settlement of subgrade was predicted by grey prediction model,it was closed of the predicted value and the measured data,and the effect of the wind-sediment-filling treatment was verified.