Study On The Principle Of Tunnel Construction And Its Application Based On ADECO-RS

In the concept and method of tunnel construction,benefited from the broad labor market,the tunnel construction method of drilling and blasting based on the New Austrian Tunneling Method(NATM) has been developed greatly in our country.However,due to the tunnel construction being risky,the harsh environment of construction site,increasing construction in the cost with rising labor costs and other reasons,to maximize reduce construction risks,improve construction environment,accelerate the process of mechanization of tunnel construction has become the challenges whitch has to face and solve in the future tunnel engineering.Therefore,the research and design of tunnel have the whole world in view,the introduction of the construction method whitch is more advanced can achieve a multiplier effect.According to the stress and strain state of core-face, ADECO-RS divided tunnel deformation into A,B,C three basic types.The advance core is regarded as a tool for the stability of the tunnel, and extrusion of the advance core is starting of the deformation of surrounding rock, which act as the most important parameters of stability analysis of surrounding rock.The ADECO-RS is a more advanced concept in the design and construction of tunnel, promotion and application of ADECO-RS is useful exploration for solving the problem of the tunnel design and construction in our country at this stage.By means of field experiment,theoretical analysis and numerical simulation,this paper made a detailed study on the principle of tunnel construction based on the ADECO-RS:(1)The basic theory of the ADECO-RS was described,and the cases of tunnel projects based on the ADECO-RS at home and abroad were analyzed,the unique advantages and the prospects of application of the ADECO-RS was pointed out.(2)The program of monitoring extrusion of advance core was designed,which applied in support project.The developed discipline of extrusion of the advance core has been received.(3)Based on GSI surrounding rock classification system,considering effects of structural plane to rock stress – strain of tunnel face,and using numerical simulation software FLAC3 D, the construction site was simulated.Then the value calculated extrusion deformation was compared with the measured data,whitch showed that the testing program was relatively reasonable.(4)The development status of arching effect in surrounding rock of tunnel was introduced and analyzed.Calculation formulas of rock pressure around the advance core was proposed based on the incomplet arching,and the influence of different parameters on the rock pressure was analyzed.What’s more,we deduced a calculation formula of the reinforcement parameters of the advance core based on ADECO-RS,and combining a simple example,the applicability of the theoretical formula was proved.(5)Considering the three-dimensional stress and strain state of tunnel excavation, combined with the GSI surrounding rock classification system and the Convergence-confinement Method,stability of surrounding rock of support project was assessed.And then, the condition of full face excavation of large span tunnel is pointed out.(6)The rationality and correctness of the ADECO-RS was explained based on three-dimensional dynamics of the tunnel excavation,and on this basis,a detailed discussion of the similarities and differences between ADECO-RS and NATM.