Study On Temperature Field Distribution Law Of Pavement Structure In Seasonally Frozen Regions Considering Extreme Climate

Pavement structure was exposed in the prolonged effects of the naturalenvironment, its internal temperature distribution changes with the effect ofenvironment.53.5%of China belongs to the area of seasonal frozen regions,where the carrying capacity and use performance of the pavement structurechanges with the seasonal change of temperature.in-depth understand and graspthe road structure temperature field distribution characteristics in seasonal frostregion has important significance. Currently, however, the study on pavementstructure temperature field distribution and prediction model in seasonal frozenregions especially for north-east research is still relatively scarce. At the sametime, since the20th century, owing to global climate anomalies, extreme weatherevents frequent occur, and the research of extreme climate impact on temperaturefield of road structure is rarely involved.To address the problem, based on the field data collected from test bedsystem in Harbin Institute of Technology, temperature distribution characteristicand influence factors of asphalt pavement in seasonally frozen regions werestudied in detail. And the pavement structure prediction model was researchedusing statistical regression methods. The extreme climate distribution law forHarbin and the extreme weather factors on temperature field of pavementstructure were carry out. The main research contents and results are as follows:(1) Based on the actual temperature, humidity data of pavement structureand weather data, temperature, temperature gradient, heat flux and heat of thepavement structure in the cyclical changes was studied, and daily constanttemperature points was studied, exploring the interaction between temperatureand humidity of the pavement structure in the process of freezing and thawing,discussing the impact on pavement surface temperature when difference of solarradiation and snow occur; Analysis the differences of temperature and frozenlines at different pavement depths between natural soil and under the road masklayer.(2) Summarizing the existing temperature field prediction model, analysisthe applicability of the typical prediction model using measured data, exploringthe advantages and disadvantages of the prediction model. On this basis,pavement surface temperature prediction model, the roadbed and pavementtemperature prediction model along the depth were established by the parametersof radiation and temperature, and the evaluation for predicting effects of the prediction models was carry out. The results showed that: the prediction modelwith high accuracy can be able to accurately simulate the pavement structuretemperature field distribution of one-dimensional in the observation region.(3) According to historical weather data, improving the existing extremeclimate indices, proposing more extreme climate indices related to the pavementtemperature field; determine the threshold of the extreme climate indices withthe GEV distribution models, the distribution law of extreme temperatures,extreme precipitation, temperature rate during1951-2011years was obtained bythe threshold. On this basis, the impact on the pavement structure temperatureand frozen line from extreme low temperature and continuing hypothermia wasstudied; the changes of pavement structure temperature, temperature gradient andheat were explored when the temperature changing with a larger cooling andheating rate; the variation of humidity field and temperature field under pvementstructure was discussed when the outside temperature repeated fluctuationsnearby zero line.Temperature field distribution, frozen features, prediction model, theextreme climate change on pavement structure were studied in this paper, whichwill promote the development of temperature field study in seasonal frost areas,particularly in the northeast, and provide theoretical support for the extremeweather on the road structure temperature field.