Numerical Analysis of Short-term Affecting Frozen Soil Temperature Field During Asphalt Pavement Filling in High-cold Regions
In order to explore the impact of short-term asphalt pavement construction on the temperature field of permafrost in high-cold regions,thermal conductivity tests and gravel porosity tests were conducted on the materials of each structural layer of the pavement to obtain the thermodynamic parameters of different structural layers.A two-dimensional frozen soil temperature field model was established using finite element method,and the influence of short-term asphalt pavement construction on the frozen soil temperature field in April,July,and October was analyzed.The results show that the thermal effect of short-term asphalt pavement construction results in a trapezoidal distribution of frozen soil temperature field.Among them,the pavement construction in July caused a maximum temperature increase of 2.13 ℃ in the permafrost layer,and the depth of the 0 ℃ isotherm decrease of permafrost was greater than 0.78 m,which was the most unfavorable for the temperature stability of permafrost.Therefore,based on the concept of equivalent deflection,temperature improvement and stiffness compensation design are carried out on the top surface of the roadbed by laying a crushed stone layer.The results show that laying a 1.0 m thick gravel layer reduces the temperature of the roadbed and permafrost layer by 1.89～27.22 ℃,and the 0 ℃ isotherm rises by 0.54～1.95 m.The equivalent elastic modulus of the roadbed top surface can be increased to 125～180 MPa,which can provide reference for highway construction in high-cold permafrost areas.
highway permafrost roadbedasphalt pavementtemperature field0 ℃ isothermcrushed stone roadbed
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