Prediction of tunnel surrounding rock deformation based on fractional operator grey theory

• 1、Schoool of Civil Engineering, Guizhou University, Guiyang 550025, China
• 2、China Nuclear Huatai Construction Co., Ltd, Shenzhen 518055, China

Abstract：When the New Austrian Tunneling Method is used to excavate the tunnel, the stresses in the surrounding rock are redistributed. It is necessary to monitor and measure the deformation of surrounding rock of the tunnel. For making an effective prediction, the data from monitoring and measuring which will affect working conditions should be analyzed effectively. In order to avoid some uncertainties such as complicated geologic factors and mechanical effects of surrounding rocks, the grey theory of fractional order operator is used to analyze the data. This paper introduces the basic principle and operation steps of the grey theory of fractional order operator. In order to establish the grey prediction model of fractional order operator, it introduces fractional order to adjust the quantity level of cumulative number accurately based on the traditional GM(1,1) model. Taking engineering example as research background, this paper compares and analyses the prediction results of the displacements of tunnel surrounding rocks under different models. The results show that the grey prediction model of fractional order operator which is superior to the classical GM(1,1) model and has obvious improvement on simulation precision can meet the requirement of practical engineering.

Keywords： rock displacement displacement forecasting fractional order operator grey model