Technology Research On The Treatment Of Soft Subgrade Byapplyingarolian Sand In Hetaoarea

In view of the reinforcement soft subgrade method using the aeolian sand substitute gravelin Hetao area soft subgrade fundus, many scholars adopted the sand gravel cushion, rubble pilescondensed by vibrating method, strong riprap, riprap extrusion sludge and other chemicalmethods of compaction to solve the soft subgrade fundus treatment, but using the aeolian sandreinforcement soft subgrade technique is almost blank. This thesis investigates the aeolian sandbeing applied to reinforcement of soft subgrade in the hetao area swamp low-lying lands andwetlands substitute grit. The creative contributions and conclusions may be summarized asfollows.Firstly, the physical characteristics and engineering properties of the aeolian sand in HeTaoarea Kubuqi desert were researched, and the Hetao Aeolian sand in terms of its natural gradation,moisture in natural dry state, nonuniformity coefficient, curvature coefficient, modulus offineness, CBR value, modulus of resilience and compressive features were figured out. Thehydro-mechanism of aeolian sand was also researched.Secondly, the soft subgrade characteristics in the hetao area swamp low-lying lands andwetlands were analyzed. And the soft subgrade has the characteristics of higher water table,smaller shear strength of the roadbed foundation and lower carrying capacity. In view of the softsubgrade characteristics and capacity requirements of the test section, the different section ofK936+800~K937+300foundation reinforcement methods and construction technologies wereresearched. The test section K936+800~K937+250was adopted the base filling aeolian sandcushion and then compacted reinforcement method, and the test section K937+250~K937+300was adopted laying gravel, rock ballast and cushion laying permeable material in soft subgrade,in order to compare the reinforcement effects of the aeolian sand cushion and gravel cushion.And, the different foundation settlement and stability of the test sectionK936+800~K937+300after reinforcement were dynamic monitored. The experimental resultsshowed that the date settlement of the various embankment settlement plates and thedisplacement rate of roadbed slope were less than the subgrade control standards of theconstruction period, which reflect the filling aeolian sand cushion in soft foundation is scientific,feasible, and able to fully meet the requirements of roadbed construction.Finally, the different reinforcements of the test sections K936+800~K937+300roadbed softground were numerical simulated. The results show that aeolian sand being applied to treatmentsoft subgrade in the hetao area swamp low-lying lands and wetlands is consistent with the experimental results of gravel being applied to treatment soft subgrade, so using the aeolian sandbeing applied to reinforcement soft subgrade substitute gravel in Hetao area soft subgrade fundusis feasible.So, the method of experiment and theory shows that the aeolian sand can be substituted thegravel to reinforcement the soft subgrade in the hetao area swamp low-lying lands and wetlands.Research results will be used for treatment the soft subgrade in the hetao area swamplow-lying lands and wetlands and desert areas subgrade treatment, which can reduce the projectcost, draw materials convenience, shorten the construction period and protect environment.