Research On Observational Construction Technology In Shaft Of Shallow Section Of Tongluo Shan Tunnel Near Shaft

With the continuous development of the modern traffic, many highways are programming and constructed. Thus, many tunnels are constructed so as to shorten the driving mileage and increase the traffic efficiency. Since tunnels are longer and wider, the technology is more complex. More tunnels will pass through the Shallow Burying and in Water-abundant Soft Surrounding Rock. The choice of the construction method will affect the construction safety and security. The thesis studies on the information construction of the Shallow tunnelling, based on the construction of the Tongluo tunnel, combining the method of numerical simulation. The main conclusion and results are shown as follows:1 The Tongluo Shan tunnel is pre-reinforced using Grouting from ground surface method. First, the cranny ratio of rock mass and the filling coefficient is judged through the test. Then according to the decline curves, the grout divergence radius is determined. improved. Research results can provide security guarantee for digging speedily and practicable technical measures for tunnel construction project successfully completed. And it will provide references to surface pre grouting in later work.2 According the NATM Mechanism, we formulate the test scheme and test in site. The Convergence curve rises first, then tends to be gentle. About 20 days later, the deformation tends to be stable. The deformation curve is in accordance with the negative exponential function, which can predict the deformation.3 Through the test of the surrounding rock pressure, it's concluded that the pressure first increases, then tends to be stable. The force of the structure is becoming stable. Also, the pressure of the Arch waist is greater than that of the vault, and the pressure of the arch is generally greater than that of the sidewall. What's more, in shallow buried section, the surrounding rock pressure increases as the buried depth increases. The lateral pressure coefficient is between 0.55 and 0.8.4 By the numerical simulation method, the displacement of the Shotconrete lining structure is solved step by step. Then based on the result, we could get the criterion of surrounding rock stress. The surrounding rock pressure in Grade V is less than 0.18Mpa, so the support structure is safe.5 By the numerical simulation method, the Variation of the primary support force and the secondary lining force are mastered. Then we are able to provide guidance for the rapid and safe construction in tunnel.