Abstract: Bolting surrounding rocks of coal roadway have nonlinear characteristics. In this paper, based on the largest Lyapunov exponent of deformation speed series, progressive forecasting and non-progressive forecasting methods of surrounding rock deformation speed were established to forecast the horizontal approaching speeds in two sides of one roadway in Muchengjian coal mine. The results show that the deformation speeds of surrounding rocks have chaotic characteristics, and the chaotic degree of deformation speeds between two sides is higher than that between the roof and floor. The fitting effect of surrounding rock deformation speed is satisfactory, and the fitting error is small. The prediction effect of progressive forecasting is better than that of non-progressive forecasting, and the largest predictable time is about 45 days, with the average relative error of 10.99%. Based on the progressive forecasting results, supplement support practice of surrounding rocks was carried out, and a satisfactory result has been achieved.

Key words: chaos, Lyapunov exponent, progressive forecasting, supplement support