The Interval Research On Backfill Layer Rigidity Of All Levels Surrounding Rock

In tunnel excavations,due to the complexity of geological situations and limitations of construction technology,the overbreak of surrounding rock is inevitable.At present,the treatment of overbreak only depends on experience.More and more theoretical studies on overbreak and backfill are needed because of the lack of theoretical support for overbreak treatment.With the development of interval mathematics,interval analysis are sophisticated.Interval analysis theory is become more and more useful in solving fuzzy and incompleteness problems of engineering.In this paper,interval analysis theory is used to study the rigidity of the backfill layer, worked as follows:1、Analyzed the parameters of surrounding rocks with interval theoretical. Analyzed the parameters of rock mass and corresponding lining, got interval value of each parameter about them, deal with fuzziness and incompleteness of the parameters.2、According to mechanics, interval analysis and rigidity matching knowledge, derived the rigidity interval model of backfill layers. Simplified the model based on the actual situation, using rigidity matching coefficient to contact the force and geometry of the tunnel lining,and the input parameters are greatly simplified.3、Obtain the rigidity and modulus of all kinds of backfill layer. Solving the rigidity model through interval mathematic, got the interval value of rigidity, to provide a basis for the backfill material selection.4、Studied a new design method of tunnel lining which based on rigidity matching coefficient. With the rigidity matching coefficient, to explore a new tunnel lining design method. The input parameters about the new method are simple and easy to get, to simplify the design process, so that the lining of the design is simple and efficient.5verified the reasonableness of the interval rigidity values.Using the finite element software ANSYS, to calculate the lining displacements of choosing different backfill material.the calculated results are consistent with the predicted results, verify the correctness of the theoretical analysis backfill layer interval rigidity values.