Durability of Lime-Stabilized Clay Subgrade in Seasonal Frozen Region
Lime stabilized viscous soil is commonly used for improving subgrade soil.Its moisture and durability evaluation are of great significance to the design and construction of subgrade engineering.Based on the resilience modulus and unconfined compressive strength tests of the subgrade soil of the Shigang Railway passenger special line in Cangzhou,the moisture and durability evaluation of lime-stabilized clay was summarized.Moisture is one of the important factors affecting soil engineering properties,and test samples are prepared under three different molding moisture contents:optimal moisture content,dry state,and wet state.The results show that the influence of water on the resilience modulus and unconfined compressive strength of lime-treated soil is less than that of untreated soil,and the resilience modulus and unconfined compressive strength of lime-treated soil increase with increasing lime dose.The durability study involves samples prepared at optimal water content and tested after 10 and 20 freeze-thaw(F-T)cycles in a controlled environment chamber.The resilience modulus and unconfined compressive strength of the F-T damaged samples are compared with those of undamaged samples.The results indicate that the elastic modulus of untreated soil decreases significantly after 20 F-T cycles(≥80％).Due to the F-T action,the rebound modulus value of the lime-modified soil is reduced by less than 35％and therefore exhibits less damage than untreated soil.In addition,the field saturation state is simulated in the laboratory to observe the worst wetting conditions of the pavement during its service life.Untreated wet samples collapse completely;however,the lime-improved soil remains intact,and its modulus value does not change significantly after soaking.
万方数据
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