Research On 3D Modeling Of High Geothermal In Complex Deep Buried Tunnel Environment Based On Surface Temperature And Borehole Data Fusion

There is a wide distribution of geothermal energy along the plateau railway,with a long high temperature section in the tunnel.During tunnel excavation,high-temperature hot water may seep out,leading to the problem of high temperature and humidity in the working environment around the tunnel.When conducting tunnel operations in high temperature and humidity environments,there are a series of problems such as environmental degradation,reduced construction efficiency,and health hazards for construction personnel.Therefore,in response to the problem of high temperature heat damage,how to analyze the location of high temperature hazards in tunnels and achieve accurate and advanced prediction of high temperature heat damage during tunnel construction has become the key to tunnel geothermal treatment.To address the above issues,this paper combines the surface temperature of the Layue Tunnel and tunnel drilling data to construct a three-dimensional temperature field,and voxelize the region to generate an equivalent surface of the tunnel temperature field.The main achievements and understandings of the thesis are as follows:（1）A three-dimensional modeling method for temperature field in deep buried tunnels was proposed.Using a high-precision high-resolution voxel model and Kriging algorithm,precise prevention and control of high temperature disaster risks in complex deep buried tunnel environments were carried out.Considering the effects of spatial correlation,adaptation,and the accuracy of related parameters,a set of efficient and practical three-dimensional modeling methods and analysis ideas for high temperature fields in complex deep buried tunnel environments were proposed.Compared with the results of typical tunnel models,it is found that the proposed three-dimensional modeling method and analysis idea for high ground temperature field in complex deep buried tunnel environments are effective.Secondly,the three-dimensional modeling method and analysis idea have good application prospects in the field of high-temperature heat damage areas,and can effectively reveal the spatial distribution characteristics of high-temperature heat damage areas.（2）A generation technique for tunnel environment voxel models considering fracture characteristics was extracted.Based on the impact of fault zones in the research area,a generation technique for tunnel environment voxel models considering fault characteristics was extracted.Combining the digital elevation model of the area and the digital terrain model of surface temperature,reasonable voxel scale division rules were designed to ensure that the voxel grid covers every interpolation point.The model incorporates fracture features to provide a more realistic representation of the tunnel environment,which can further effectively analyze the spatial correlation between fracture zones and temperature field distribution.（3）The distribution characteristics of the temperature field in the Layue Tunnel were predicted.The distribution characteristics of the high ground temperature field in the Layue Tunnel are revealed from the aspects of fault feature extraction,geological analysis of the Layue Tunnel,and geothermal gradient analysis of the boreholes in the study area.Subsequently,T_H,H₀,temperature gradient,and groundwater active zone or geothermal influence depth were determined,and the ground temperature prediction for the Layue Tunnel was completed.The feasibility analysis of the results was conducted,and it was found that the conclusions obtained were good.（4）A numerical model of the temperature field in the Layue Tunnel was obtained.The numerical model of the ground temperature field in the longitudinal section of the tunnel indicates that the heat source of the tunnel thermal damage is mainly controlled by the influence of the Yajiang suture zone.The Grade V severe thermal damage accounts for 42%of the total length of the tunnel,Grade IV severe thermal damage accounts for 7%of the total length of the tunnel,and Grade III moderate accounts for 19%of the total length of the tunnel,the Class II minor thermal damage segment accounts for 16%of the total length of the tunnel,and the Class I non-heat damage segment accounts for 16%of it.