Study On Frost Heaving Characteristics Of Subgrade Soil In Alpine Meadow Region

Subgrade seasonal freezing and thawing is obvious in alpine meadow, due to its special environment. The seasonal freeze thawing causes Pavement cracks, frothing and a series of diseases, which will influence the normal operation of the road, security risks. Therefore, it is necessary to research the characteristics of subgrade soil frost heaving in alpine meadow area. Meanwhile, it will provide a reference for the study of occurrence of frost heaving and developing mechanisms and provide guidance for the anti-frost measures proposed road.This article relies on Gongjue to Mangkang Freeway Improvement Project in alpine meadow area, through internal testing and finite element analysis to study the frost heaving of subgrade soil characteristics. It is focuses on the frost heave during the process of water, heat and stress field change. The main work is summarized as follows:(1) The basic physical and mechanical properties of subgrade soil, based on the physical composition of soil, reference to the indoor standard freezing test equipment, to design and manufacture of indoor freezing test system for the characteristics of subgrade soil in alpine meadow area.(2) Analysis the factors of affecting subgrade soil frost heave, from the outside temperature, freezing, soil in fine particle content and initial water content to design the indoor of freezing test plan. And a total of 24 groups of indoor test to get the conclusion that the subgrade soil of variation in the process of freezing temperature, moisture, and displacement distribution under different experimental conditions.(3) Evaluation of Subgrade Frost Heaving characteristics, regression analysis of subgrade soil heaving deformation rate, different way of freezing, frost heave deformation rate regression equation are obtained, and analysis of frost heaving deformation rate and its influential factors.(4) Reference the equation of soil water, heat, force, introduction of dynamic equilibrium relation, and establishing the three field coupling mathematical model of subgrade soil. Mathematical model is introduced into the finite element analysis software, respectively, the establishment of Unidirectional Freezing, around freezing two-dimensional numerical model, model verification. Studying the changes of physical field is based on the simulation during the process of freezing.The research results of this paper can provide reference for the further research on Subgrade Frost Heaving Mechanism and provide guidance for research on subgrade frost prevention measures in alpine meadow area.