Notice of RetractionEvaluation on the Stability of Rock Mass Deformation Based on Chaotic Muation -RPNN Model
To analysis the stability of rock mass long-term developing deformation,the chaotic muation -RPNN model is built. Combining the chaos theory,the muation theory is introduced, and the stability of rock mass deformation is evaluated by chaotic muation -RPNN model. The lost measured displacement data are interpolated by using the higher order polynomial methos, and the long-term displacement is forecasted,and the stability of rock mass long-term developing deformation is analyzed. Research shows that the strend of predicted displacement is approximately the same as that of measuring displacement,and there is no suddenly dropped or sudden increased phenomena,and the displacement increasing strend of some measuring point remains stable with Lower growth trend, and the deformation of rock mass is strending to be stable.
Multi-Offset Recurrent Neural Network Model for Displacement Prediction of High Wall Rock Mass
It’s an important research project to forecast deformation of high wall of underground house during designing and constructing. The neural network is optimized and the multi-offset recurrent neural network is built to predict deformation. The maximum predictable number of days is calculated by calculating the maximum Lyapunov exponent, and the structure of neural network is optimized through chaotic characteristics. The example shows that the errors between prediction values and measuring ones are all no more than 10%, so the precision is high and results are credible on real time.
RESEARCHES ON DEFORMATION AND FAILURE CHARACTERISTICS OF AN UNDERGROUND POWERHOUSE WITH COMPLICATED GEOLOGICAL CONDITIONS BY DDA METHOD
As a numerical modeling approach,discontinuous deformation analysis(DDA) method was employed to analyze effects of different factors on the deformation characteristics of an underground powerhouse.The effect factors mainly consist of stress lever coefficient,rock reinforcement,joint structure pattern and strength properties of joints in surroundings,etc..It has been shown that DDA model can get reasonable results with different simulation cases.The deformation of surrounding rock mass is closely relevant with rock stress conditions assumed beforehand.As the surrounding rock mass has the characteristics of hard and soft rocks being formed alternatively,where the multi-layer of shear zones exists between them,the displacements of sidewall have larger increasing intervals compared with those of roof arch displacements of the powerhouse when horizontal stress increases;and the discontinuous sliding along surfaces of shear zones will occur normally.Reinforcement with rock bolts will bring favorable effects on rock surroundings in controlling deformation and stress distribution properties.If a series of key blocks collapse,the joint intersections in surrounding rock mass,in some cases,will exert negative effects on the stability of powerhouse.On the other hand,for joint intersections being under stable state,unstable deformations of rock surroundings will occur when the joint strength is reduced to some extent.This paper presents some relevant results with DDA method,and some problems associated with DDA have been discussed.