Comprehensive studies on the dynamic behaviours of a high rock slope of the Three Gorges shiplock and a blocky arch structure are performed using the distinct element method (DEM). Some additional functions have been incorporated into the current DEM code, including a scheme of non-uniform seismic input on the boundaries and an improved triangular mesh generator for deformable elements. Parameters from the field and laboratory tests of the project are used in the analysis of the shiplock slope. Comparisons between the DEM results and the field measurements under the excavation unloading process are made and the good agreement obtained demonstrates the effectiveness of the DEM for predicting the deformation process of the slope. The above examples of the high rock slope and the blocky arch demonstrate that the effects of different earthquake input, input mechanism andparameters on the dynamic response behaviours and collapse pattern of the systems are significant.

Based on the dynamic theory for saturated porous media by Biot (Journal of the Acoustical Society of America 1956; 28:168–178), a numerical model is presented to analyse the resection behaviours of reservoir sediment and compared with those from the visco-elastic model. It is concluded that the two models give very similar results of resection coefficient α within the frequency range of interest. Then, using the two models, the change of the resection coefficients α with various sedimentation parameters and excitation frequencies are studied in detail. The results are further used in the analysis of response functions of hydro-dynamic pressures on, and structural displacements of the Xiang Hong Dian arch dam, for which some results from a Celd vibration test are available. It appears that e2ects of water compressibility with sediment resection on hydro-dynamic pressures and structural response are not signiCcant for this speciCc case. Copyright

A procedure is presented for the analysis of the stability and propagation of cracks in arch dams based on linear elastic fracture mechanics and three-dimensional boundary element modeling. A simplified crack propagation criterion is employed and the crack trajectories arc obtained by multistep extension. The first up stream cracking which occurred in the Kolnbrein arch dam is studied in detail under various conditions conceming the foundation interface, location of crack initiation, reservoir water level and load combinations. Crack trajectories close to the observed one are obtained with water level at 1, 850-1, 860m, which agrees with the prototype experience. It is found that the hydrostatic load and associated uplift pressure on the crack surfaces are the key factors for causing an initial crack at the dam base to propagate to the upstream face. It is also noted that the bonded condition at the interface between the dam and the upstream elevated foundation is responsible for producing the distinctive profile of the observed crack, which daylights on the upstream face at an acute angle.

The earthquake behavior of arch dams is studied including dam-canyon interaction and nonlinear response of dams due to contraction joint opening and joint reinforcements. Significant effects of canyon radiation damping, non-uniform free-field excitations and nonlinear joint behavior on dam response have been confirmed.

A coupling model of Finite Elements (FEs), Boundary Elements (BEs), In