Study On Numerical Analysis Method Of Thermal Influence Of Highway Corridor In Permafrost Region

Permafrost is a kind of soil with high thermal sensitivity and serious engineering threats.Global warming and human activities lead to the increase of frozen soil temperature and even degradation,which makes highway engineering in permafrost regions face complex natural environment and serious permafrost disease.With the rapid development of China's expressway network in the western region and the existence of a large number of permafrost regions along the highway corridor of "The Belt and Road",an analytical study on thermal effect of permafrost zone is imperative.Several studies indirectly quantitatively analyzed the impact of highway engineering on permafrost temperature by a few diseases or finite element model.Few applies high remote sensing and geographic information to analysis and quantifies the thermal effects from the perspective of systematic,long-term and dynamic based on the time series data.Compared to other regions,Qinghai-Tibet Plateau permafrost region has the features of rarefied air,extremely low temperature,unstable engineering geology,sparsely distributed population and road network,and low vegetation coverage.Appropriate amount influence factors of temperature change make it easy to control the environmental variables so as to analyze the heat influence of road in the frozen.In this paper,the study area is located in the permafrost region of the Qinghai-Tibet Plateau.The Highway Corridor is defined.On the basis of the heat conduction mechanism,the affecting factors of the landform,surface types and road types are investigated to explain the reason of temperature change in the study region.Based on entropy theory,the entropy model of Highway Corridor is constructed to describe the orderliness and disorder of the geothermal change.According to the characteristic of the time-series thermal data,spectral analysis is applied to calculate the related parameters of entropy model.Using advanced technology as remote sensing and geographic information system,the method of collecting and processing the multi-source data of the environment is suggested,providing data support for analyzing thermal impact of Highway Corridor in permafrost regions.Considering the geothermal entropy calculated by the entropy model as an engraved ruler to characterize the thermal state of the ground temperature,the mathematical methods,such as spatial statistics,spatial autocorrelation analysis and logistic regression analysis in GIS and SPSS are applied to analyze the temperature characteristic of the whole life cycle of the highway construction project.And a classification method of geothermal entropy under the multi-factor environment is proposed.Finally,a some Qinghai Tibet Plateau permafrost area containing new and old expressway is chosen as the study area.Entropy model is calculated.Data is obtained and copyed.The average entropy of two highways under multi factor environmental conditions is Comparative analyzed.And the thermal impact grade is calculated.Quantitative analysis of heat impact analysis of Highway Corridor belt in Permafrost Region is realized,verifing the feasibility and the effectiveness of the proposed method in this paper scientifically.The results of this study can be used to build the route choice environment database of large range,long time data to improve highway designer's efficiency,which is laid the foundation to the urther study the method of linear location in permafrost regions at the next stage..The study results has great significance in both scientific research and practical application.