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Research On Temperature Field Of Embankment And Pavement And Temperature In Index Of Pavement Working Environment

Posted on:2007-12-29Degree:DoctorType:Dissertation
Country:ChinaCandidate:C N SongFull Text:PDF
GTID:1102360185981702Subject:Road and Railway Engineering
Abstract/Summary:PDF Full Text Request
Desert area lies in the Chinese north, nature environment is worse, summer is very hot that the highest soil surface temperature gets about 70℃, and winter is very cold that surface temperature drops under -30℃. Pavement brings about mach damage in the environment. The damage of pavement deformation caused by embankment frost heaving is much serious in cold and wet region. The damage relates to temperature of embankment and pavement. In order to avoid road damage happen in pavement working, temperature of embankment and pavement should enough be considered in the course of high-lever desert highway design and construction. Combining with the technological study of west highway construction, this paper systematically studies relationship between temperature of embankment and pavement and continuously variable nature environment factors. Main conclusion is following:Based on Harlan model and Darcy law and considering temperature gradient influence on moisture transfer, the authors of this paper derive from a two-dimension mathematical model of coupled moisture and heat transfer during aeolian sandy embankment freezing, present boundary condition of coupled question on basis of the principle energy balance on soil surface, analyze calculation formulas about moisture , heat parameters and soil water contain and density by using conference existing material dates. Totally implicit difference scheme and linear iterative in each time step are used to solve the non-linear equation of coupled moisture and heat transfer. Comparing with Harlan model, Temperature gradient influence on moisture transfer is considered in the mathematical model, third boundary condition that contain much actual meteorological environment factor is adopted, and road material thermal parameters is distinguished during freezing and unfreezing, which is contend with realities. The temperature and the maximum frozen depth of experimental road are measured to verify that the model reliable. Based on meteorological materials and embankment parameters of moisture and heat, both the distributions of embankment moisture and heat and the maximum frozen depth can...
Keywords/Search Tags:road engineering, desert area, aeolian sandy embankment, coupled moisture and heat equation, infinite difference scheme, moisture transfer, course of freezing and thawing, pavement structure, temperature field, numerical emulation
PDF Full Text Request
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