Application of wavelet packet analysis in dynamic computation of jointed rock mass

The deform and damage of jointed rock mass generally have the characteristic of large deformation. Its joint interfaces and faults may be the major factors which cause those dangerous dynamic responses. There are many limitations on mesh grids division and damping demands when time-process method is used in analyzing seismic response, in case unreasonable high frequency components of the response may be created. Considering that although the vibration signal is rich in spectrum, there are usually one or several frequency bands, in which energy concentrates on some areas and amplitudes are higher than others, they form the predominant parts in the displacement response of jointed. rock mass. When the technology of band analysis associated with wavelet transform is adopted, wavelet packet band analysis is used first to deal with incident waves, and then according to the reconfiguration waves, time-process method is applied to compute displacement response of rock mass. The results indicate that the wavelet packet is more applicable than the common. Fourier transform. The number of mesh grids and the computing time can then be decreased. It will be a good choice for slope dynamic analysis.