Simulation Study on Deformation Characteristics of Roadbeds of Lime-modified Expansive Soil

Modification of expansive soil with lime is one of common methods for road construction in the areas of expansive soil.The relevant technical specifications only stipulate that strong expansive soil cannot be used as roadbed filling and that medium expansive soil after modification treatment can be used as expressway roadbed filling,but do not state its specific mix ratio.This paper selects a section with local expansive soil foundation of some expressway as the object of study and investigates related technical indices and operating conditions of the existing highway roadbeds in expansive soil areas.By boring sampling on site,the paper chooses representative expansive soil samples to conduct indoor test and calculation of simulation model to study stress and strain characteristics of modified expansive soil roadbeds with lime.The result of study shows that addition of lime is effective for improvement of expansive soil roadbed,it is appropriate to control the ratio of added lime at 4% ～ 6%.