Frozen Model Test And Temperature Field Characteristic Analysis Of Tunnel In Cold Region

The use of frost damage caused by the high altitude cold area tunnel,which is represented by the Qinghai Tibet Plateau.Due to the impact of cold damage,the state invested huge sums of money can not be recovered,the passage of the passage of people’s lives can not guarantee security.In this paper,the artificial frozen soil model is built on the background of freezing injury in cold region.According to the limitation of the test data,a support vector machine(SVM)model is developed based on the principle of structural risk minimization and the support vector machine(SVM).1、Through the tunnel model test of cold area,the temperature variation law of tunnel model of cold area is obtained:The temperature variation of tunnel model in cold region is divided into two stages:cooling section and heating section.In this paper,we do not consider the change law of the heating section.The change law of cooling section:With the increase of freezing time,the temperature of each point in the surrounding rock decreases,and the temperature reduction rates of different sections and different measuring points are different.The whole section can be divided into two groups:Section 3 and other sections.2、According to Newton’s law of heat exchange:The amount of heat flowing from one medium to another is proportional to the temperature difference between the two media,At the time of initial freezing,the temperature difference between the indoor temperature and the freezing pipe is the largest,so the cooling rate is the fastest,With the increase of freezing time,the temperature difference between the two decreases,so the cooling rate slows down;In the late period of freezing,the temperature difference between the two is almost zero,so the temperature of the tunnel surrounding rock is not changing,and tends to a stable value.3、The cooling of position 3 presents a law of decreasing logarithmic function.The reason is that the location of the 3 temperature sensor layout,layout is more uniform,the response of the tunnel surrounding rock temperature change is more accurate;Other locations of the cooling law generally showed a linear trend.4、Based on the introduction and derivation of SVM method,the SVM model of artificial frozen soil temperature field is established.5、Through the different kernel function is applied to the model,by comparing the selected kernel function is most suitable,then to predict the temperature,through the comparison with the measured data,we found that the predicted values have little difference with the measured value,the rationality and correctness of the model.