Seasonal Frost Area West Failure Mechanism And Study Of Soil Frost Prevention Technology

The area of seasonal frozen region is 513.7×104km2, accounts for about 53.5% the land area. The influence of seasonal freezing climate on the quality of highway projects is very significant. With the freezing and thawing of water in soil, the longitudinal cracking and frostheaving uplift appear on asphalt pavement frequently during frozen period, subsidence deformation and frost boil phenomena often appear during the spring melt, which can reduce pavement quality and affect traffic safety and increase maintenance costs.Considering synthetically the factors of frozen area, highway natural regionalization, the standard deep-freeze, soil, topography and so on considered, systematic investigation on frost damage of roadbed is carried out. At the same time, taking the influence of pavement, roadbed section and route direction on deep-frozen of the road into consideration, drilling investigation is conducted on the typical section. The tests of frost properties of roadbed soil, bending properties in low temperature of pavement materials and strength degradation of roadbed soil are completed in laboratory. And the physical works for observing characteristics of frost heaving and freezing control techniques also are constructed after design. Using drilling data, test results and observations of physical works, frost heaving and frost damage mechanism of roadbed are analyzed. Indexes of character of frost heave are proposed. Also, frost heave tester of roadbed soil is improved, and test methods are revised. The factors and rules on frost heaving of roadbed and deep-frozen of road are summarized. Finally, principles and main point of control technology are proposed and the guide is formed.The research results can be used to design, construction and maintenance of roadbed in seasonal frost regions so as to reduce the roadbed damages, lower maintenance costs, extend the performance and service life of pavement and roadbed, which is in accordance with the national basic national policy of environmental conservation. Therefore, it has broad market prospects and a good application value.