| The Geotechnical Engineering back analysis is an important embranchment of the rock and soil mechanics.It has a history of more than 30 years, and has formed a mature theory system that can be applied to the engineering practice. But for more designers and constructors who work in the front line, the theory of back analysis is too abstruse to understand and rarely applied to the project on their own initiative.The current situation results from the abstruseness of the theory itself for one hand and few special application software is developed for the other hand.This paper is a summary of recent research against this background.Firstly, considering the mechanics status of the excavated surrounding rock and the uncertainty essence of many problems in rock mechanics, the Kalman Filtering&FEM coupling back analysis method considering broken rock zone is established and programmed in FORTRAN90 based on the original extended Kalman Filtering& FEM coupling back analysis programming.Secondly, using the interactive communication technology between FORTRAN and VC++ based on the operating files, the back analysis module is added into the tunnel construction monitoring and measuring intelligent information management and analysis system, and the back analysis is realized conveniently and visually based on the graphics module of the system.Any theory or method is established for the engineering application. Lastly, the method has been successfully applied in the surrounding rock stability analysis of the Baiyun tunnel YK48+737. After the initial parameters have been worked out based on the Kalman Filtering&FEM coupling back analysis method considering broken rock zone, the maximum shear strains of the global calculating field are obtained based on FEM. And then, by comparing with the critical shear strain obtained by experiment and theory deduction, the stability of the surrounding rock could be judged. Because the method mentioned above discards the unreasonable hypothesis of the initial stress field, the results are more practicable and reasonable. The on site designers and builders would be able to know the stability situation of the surrounding rock in time, and improve their design and construction.The main innovations of this paper are as follow:(1) The Kalman Filtering&FEM coupling back analysis method considering broken rock zone is established and programmed in FORTRAN90; (2) Using the mixed programming technology, the back analysis module is successfully added into the tunnel construction monitoring and measuring intelligent information management and analysis system. |
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