This paper presents the results of experimental studies to examine propagation of fault ruptures with particular concern on dip-slip fault. The pattern of rupture propagation through a sandy soil and the location of surface rupture were investigated. The distortion of surface ground accompanied by fault rupture has been examined as well. The 1-g model tests showed that the location of surface fault rupture varied depending on the model thickness due to strongly dilatant behavior of sand under low confinement. However, the increase of confinement at centrifuge models provided no definite variation of the location against the change of model thickness, which suggested the importance of interpretation about the results from small scale sandbox test.

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This paper presents an improvement of the current wind zone map of the Philippines. The Generalized Extreme Value (GEV), Gumbel and point process models were used in characterizing the extreme wind speeds in the Philippines. Available daily maximum wind data from 50 stations in the Philippines were also used in the analysis. The results show that the standard errors in the point process model are lower than the GEV or Gumbel models making it a better model. Finally a regional wind zone map (6 zones) was developed using extrapolated 30, 40 and 50 year return wind speeds from the point process approach. Wind zone maps were developed using kriging interpolation method of ArcGIS Geostatistical Analyst.

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Multi-channel planar array probes had been developed in order to improve detectability of three-dimensional defects. The ultrasonic system, which is applicable to the planar array probes, was developed in order to make the compact and fast detection system. Specific 3D SAFT algorithms were proposed for the planar array probes. Experiments for verifying the improvement in detectability of three-dimensional defects and the advantage of the 3D SAFT processes were performed. The results show that the planar array probes and the 3D SAFTs show great improvement in detection and information of defects in three dimensions.

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Based on the dynamic substructure technique, the author proposes a static seismic analysis method, the Ground Response Method, for underground structures modeled on the structure and surrounding soil that is expressed using finite elements. By comparing existing static seismic analysis methods, it is verified that the Ground Response Acceleration Method for Buried Structures provides results almost equivalent to those obtained from the Ground Response Method. However, the FEM Seismic Deformation Method yields different results. Thus, the author proposes a new seismic load that is equivalent to seismic ground strains and modifies the FEM Seismic Deformation Method.

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In this study, effects of multiple detonations on reinforced concrete (RC) slabs has been experimentally investigated to improve design and damage estimation methods of RC shelters. One of main results obtained is that crater and spall depths of the RC slab for a double detonation may be relatively well predicted by modifying our damage prediction method, which was previously applied to a virgin RC slab subjected to a single detonation.

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