Numerical Analysis Of The Gray Theory In Tunnel Construction And Construction

Tunel and underground engineering is a grey system by themselves due to the complicated hydrogeological environment and many uncertain factors. Information construction could feedback information timely based on the practical monitoring condition during construction process, building the judgment rule of ground in ultimate stabilization time, ultimate distortion and so on, it could avoid magnitude accident availability, achieving the safety and economic of tunnel engineering.There exist some shortcomings on the model parameters and its methods of evaluation in the traditional study of grey system. Based on the systematic study of the various theoretical prediction models of grey system and correlation analysis methods, the author in this paper, attempts to make some effective discussions to this model and evaluating methods, and tries to applicate these improvements to engineering practice. The tunnel designing principles, methods, the applicating technologies, and the main research in this paper are mentioned as follow:1. This paper studied grey correlation analysis, calculation methods, and the applicable principles on the Tangs grey correlation deficiencies in the application. Based on the grey theory used in the information construction, grey correlation analysis method has been led into. grey system theory of a classification of gray rock has been eatablished and put into study, thus optimizing the tunnel construction program.2. Presenting the suitable conditions of the classical GM (1,1) model:â‘ The classical GM (1,1) descriped the dynamic linear system, with a trend of exponential decay or increase.â‘¡During the forecast period, when put the GM (1,1) into predict, the dynamic behavior of model system should match with the characteristics of object behavior of the dynamicâ‘¢GM (1,1) model, is available only for short-term forecasts .3. Aim at the problems in GM (1,1) model, in this paper, DGM (2,1) model, Verhulst model GM (1,1) model parameter optimization, DGM (2,1) model parameter optimization, and Verhulst parameters Optimization Model have been studied, significantly improving the accuracy of the model error. Examples mentioned here have showed that GM (1,1) model fit the short-term forecasts to the displacement in the tunnel rock; DGM (2,1) model and Verhulst model are superior to GM (1,1) model, because of the higher precision error for displacement of the tunnel rock deformation and the more suitable to that forecast.4. The basic principles of the information design and the application of the measuration information on the information construction were introduced. From the monitoring outcome, the measurement can reach the convergence project, rock can remain stabilizing, which proved that the initial support parameters on the crossing tunel meet the practical requirements, and the top and bottom benching tunneling is appropriate.5. In this paper, the author imitates the tunnel dynamic excavation process using FLAC2D based on the construction of mountain tunnel; compares the different changes in the excavation of rock through different ways: the gross excavation and the excavation of rock with Shotcrete- bolt Supporting; analysises the reinforcement mechanism to the soft rock with Shotcretebolt Supporting; and analysises the stability of the tunnel, as well. The coincidence between numer- ical simulation results and the actual measurement results proved the supporting the feasibility of the supporting programme used .