Mechanism Research On The Combination Support System Of Yielding U-steel In Soft Ground Tunnel

More than 70 percent of energy is coal which occupies a pivotal position in construction of national economy in our country. With the development of coal mining's depth, the problem of supporting and maintaining for soft ground tunnel becomes more and more conspicuous. Whether we can solve it properly is the keypoint for coal mining's development in depth and safety in production. So the thorough studying and exploring is urgent.This thesis makes a systematic exposition for the characteristics and mechanics property of soft rock, characteristics of broken soft ground tunnel, influence factors of ground's deformation, supporting principle of soft ground tunnel and maintenance methods of tunnel etc. Proceeding from the bearing mechanism of soft ground tunnel, this thesis analyses the principle of interactin between soft ground tunnel's supporting and surrounding rock, and it proposes the view of the yielding U-steel complemented backfilling and grouting support in this foundation.This thesis applies emphatically finite element analysis programmes FLAC^2D to analyse the deformation and pressure calculation of soft ground tunnel's surrounding rock and supporting. We make a systematic analysis for the breaking forms and the influence of major effect factor to support bearing capacity, and conduct a deep research, analysis and calculation for the combination support system of yielding U-steel.Mode experiment, supporting practice and observation analysis for Beigui transport tunnel at Chensilou coal mine in Henan are done to verify mutually with the numerical simulation analysis result.This paper studies with the practice unifies, and it promote the engineering analogy method to quantitative analysis. The thesis searches a new way to calculate the pressure and deformation of soft ground tunnel's surrounding rock and supporting. It will play important role in soft ground tunnel supporting.