The Analysis Of Seepage Field And Its Effect On Unsymmetrically Loading Tunnel

China is a big country with complex topographic and geomorphic conditions,especially the mountainous area,which is more than two third area of territory.Tunnel engineering has made a great development since 1826 when the world's first railway tunnel was built in UK.It is a highly effective replacement for circuitous road when facing problem such as mountains.Because of its advantages such as adaptation to harmful environment,improvement of travel efficiency,protection of natural environment and improvement of space utilization,today,tunnel is one of the most main techniques which can pass through mountains and other obstacles.Tunnel is a typical underground structure so the groundwater is one of engineering challenges in the whole process of construction and application.The permeability of rock is usually particularly low,but for rock mass,because of the complex rock pores,fractures,structural planes and tectonic zone will increase the permeability of rock causing great pore water pressure in the rock mass which results in several problems for geologic engineer to solve.With the support of the Huitougou tunnel engineering on the Hegang-Dalian expressway,this thesis studied the seepage field of shallow buried tunnel with unsymmetrical loading,and researched the bias effect caused by seepage flow of underground water.The main contents are as follows:1.This thesis introduces the basic theory of seepage field of tunnel rock wall from the respects of seepage flow model,basic seepage equation and definite condition of seepage flow.Combined with related theory,this thesis analyzes the mechanism of interaction between fissured rock seepage flow field and stress field and elucidates the necessity of revolting the tunnel stability.2.Based on detailed geologic survey of Huitougou tunnel and the theory of hydro-mechanical interaction,the regularities of seepage field distribution of unsymmetrically loaded tunnels are analyzed under the most unfavourable engineering conditions of representative emblematic section.3.Flac3D was employed to analyze the stress field of Huitougou tunnel.Though the comparison of aspects of stress field and displacement field between single field analysis and multi-field analysis which includes seepage field with and without considering hydro-mechanical interaction and stress field,the influences of hydro-mechanical interaction and seepage field on unsymmetrically loaded tunnels was studied.In addition,the comparative analysis between measured and calculated value of surrounding rock pressure was also conducted in this study.