Experimental study on water and salt migration of replacement layer saline soil subgrade in Hexi Corridor
There are a lot of silty saline soils in Hexi Corridor of China,and its capillary action is obvious,which has caused serious harm to highway subgrade.Based on the above reasons,in order to clarify the water and salt migration characteristics of the replacement subgrade,this paper uses the self-designed water and salt migration test device to carry out indoor experimental research,and analyzes the failure mechanism of saline soil from the micro level by means of scanning electron microscope(SEM)test.The test results show that in the replacement functional layer of loess and saline soil mixed with aeolian sand,the water and salt migration is mainly concentrated in the early stage of hydration.With the increase of aeolian sand content,the water and salt migration rate of the replacement layer first increases and then decreases,and the fastest migration rate occurs in the soil sample with sand content of 30％.The results of SEM show that after the migration of water and salt,salt crystals will be precipitated and filled between soil particles to form cements and agglomerates,resulting in soil cracking;when 50％ aeolian sand is added to saline soil,the cracks and pores caused by salt expansion can be reduced,and the damage caused by water salt migration can be effectively reduced.
subgrade engineeringsaline soilaeolian sandwater salt migrationreplacement layer
NETL
NSTL
万方数据
