Study on Application Effect of Sand Consolidating Agent for the Slope of Highway Subgrade in Season Frozen Zone

Abstract

Indeepseasonfrozenareas,thesolidifiedlayeriseasytobedestroyedduetotheinfluenceoffreeze-thawcyclesafterthesurface layer of the sandy slope is solidified by chemical methods. In order to study the application effect of the new sand consolidating agentaftersolidifyingsandbody,themechanismofstrengthformationwasanalyzedbyscanningelectronmicroscopy(SEM).The freeze-thawcycletestswerecarriedoutonsandconsolidatingsamples.Thedirectsheartestsandunconfinedcompressivestrength testswerecarriedoutbeforeandafterfreeze-thawcyclestoanalyzethefreeze-thawresistanceofsandconsolidatingsamples.The sandconsolidationagentwastestedon-site,anditsstrengthwastestedtoobserveitseffect.Theresultsshowedthattheadhesive membranes on the surface of sand particles were formed by the sand consolidating agent, which increased the cohesion and strength of sand particles. After freeze-thaw cycle tests, the cohesion, internal friction angle, and compressive strength of the solidified sand gradually decreased with increasing freeze-thaw cycles. The decreasing rate reduced from fast to slow and then tends to be stable. The failure mode of samples changed from brittle failure to plastic failure. The sand consolidating layer can effectively prevent collapse of the sandy slope. Combining with the external-soil spray seeding, the sand consolidation layer is beneficial to the growth of plants.