3.4 Utilization of the map

The following are basic examples of use of the seismic hazard map for specified seismic source faults. However, it is desirable to develop them according to specific purposes.

(1) Seismic hazard maps for Specified Seismic Source Faults

In earthquake resistance design for structure and safety evaluations, the peak velocity on the engineering bedrock is expected to be a standard index for the local seismic intensity. Furthermore, the peak velocity on the ground surface on the ground is expected to be obtained based on the detailed surface geological information within the site area.

(2) Seismic waveform

Dynamic earthquake response analysis using seismic waveform, which is calculated by the detailed method, is useful for the earthquake resistance design and safety evaluations. In particular, there is an increased demand for seismic waveform to design high-rise buildings and base-isolated structures which require dynamic earthquake response analysis. The calculated waveform can be used without any modification in case the entry position of a dynamic earthquake response analysis is on the engineering bedrock. Because more than one case is provided for each scenario earthquake, it is possible to figure out the influence that seismic ground motion gives to the structure according to the different conditions.

(3) Subsurface structure model

When preparing a seismic hazard map for specified seismic source faults using the detailed method, information on deep sedimentary layers is collected and reviewed to build subsurface structure models. Subsurface structure models are particularly useful to understand the characteristics of long-period and broadband ground motions as well as to design and review long-period structures. It is also helpful to evaluate the seismic ground motions of other scenario earthquakes and site amplification characteristics.

(4) Fault model

When it is necessary to consider new scenarios, in earthquake resistance design and/or safety evaluations, it is possible to rebuild the fault model by modifying source parameters.

(5) Strong ground motion prediction method (recipe)

For dangerous (meaning earthquakes are likely to occur) active faults on land or offshore trenches, the 'Recipe' is a standard methodology designed to produce the same results regardless of the user, for the prediction of strong ground motions of probable future earthquakes. Application of this 'Recipe' enables very precise prediction of strong ground motions in a broad-band period range, which is important for disaster mitigation measures of earthquake.

(6) Adding detailed information of the site

It is possible to evaluate seismic ground motions and to design structures with higher precision by improving model for surface soil layers based on the detailed information of the site, such as subsurface information. The improved model is also useful for reviewing the earthquake resistance of more than one structure and plan earthquake disaster mitigation measures and restoration programs. In addition, it is helpful for the estimation of damages such as paralyzed or lost infrastructure.

(7) Advanced design method for earthquake resistance

The design method for earthquake resistance is currently not yet been completed and should be improved. The seismic waveform calculated in the detailed method is useful for understanding the seismic ground motion and behaviors of structure.