Modeling and prediction of strong ground motion, including near-source effects, for earthquake engineering applications.

摘要

This thesis aims at developing physically based techniques for earthquake ground motion prediction for engineering applications. On basis of Random Vibration Theory, we establish a methodology using the Specific Barrier Source Model proposed by Papageorgiou and Aki ((1982, 1983a)[156, 157]). The advantage of this model stems from the fact that the model parameters have clear physical meaning and have been found to be very stable for a given tectonic region and may be estimated even by geological exploration methods, thus making the model very powerful in predicting strong ground motion even for areas where recordings are lacking.; For parameter estimation of strong ground motion, the specific barrier source model is incorporated in the random vibration approach. A number of numerical examples are presented to demonstrate the effectiveness of the methodology. Comparisons with recorded data and results from other source models are made to evaluate the specific barrier model.; For time domain simulation of strong ground motion, an approach based on the specific barrier model and using a hybrid Green's function, is implemented. This approach is then used to predict strong ground motion for the Saguenay earthquake of 25 November 1988, in Canada. Comparisons of the predicted and the recorded ground motion are given.; As a part of the work in this thesis, we develop modelling and numerical techniques to predict near-source ground motions. The numerical technique for near-source ground motion simulation is then adopted to predict the strong ground motion due to the 1992 Landers California earthquake. From this simulation, it can be seen that the displacements in the vicinity of the fault display a clear ramp-function shape. Large permanent displacements are observed near the fault trace on the earth surface. Another feature of this event is the directivity effects, which cause stronger ground motion in the northwest direction than in the southeast direction.; As a conclusion, the methods proposed in this thesis are reliable and efficient. They can accommodate the necessity of earthquake ground motion prediction for engineering applications.