Monday, 31 January 2011

Revised Map of Earthquake Zones Signed

The Latest revision of earthquake zone map, as part of the SNI 03-1726-2002 on the Procedures and Techniques of Quake Resistance for Buildings and Constructions have been signed.

In fact the Ministry of Public Works already had the SNI Quality Standard since 2002 for earthquake Zoning. However, with the geological movement of underground fragments, the zoning has to change accordingly.

The Minister of Public Works Djoko Kirmanto stated that the quake-mapping was the initiative of the Research & Development Center for Settlements of PU in collaboration with the related institutions. For that matter, Team 11 was formed in 2009 to draw a revised zoning map. The Team consisted of the Center of R&D for settlements, Center of R&D for Roads and Bridges, the Bandung Institute of Technology (ITB), the Center of Geology, t\The Indonesian Council of Science (LIPI), and BMK.

Indonesia’s map of quake zoning has been renewed based on the latest seismic data and up to date research findings of seismo-technology in Indonesia, which has been analyzed with reference to model of 3-D based on the applicable international standard. For example for International Building Code (IBC-2009) the probability assumption was excess of 2% for serving 50 years of building age (a period of repeated quake 2475 years) on short term period T=0.2 seconds and period T=1 second as basis for determining spectra response, of acceleration at foundation stones. To accommodate planning needs, with 10% of quake risk for serving 50 years and 100 years building’s life, a quake zoning map has been attached as well based on repeat period 475 years and 950 years, using the same format as quake zoning map of 2475 repeat period.

The revision of Indonesia’s quake map has been carried out by updating of quake epicenter relocations, and improving geometry of quake zones by tomography, identification of parameter of quake source, and creating software to be installed at website. After revision of this quake map, there would be revisions of regulations for SNI standard for steel, concrete and wood through formation of similar teams. Soon the outcome would represent many aspirations.

As part of the related quake activities, it is felt necessary to conduct further research on fragments that are suspected of being active, but whose characteristics and seismic parameter are still not clear yet. And to install more GPS on cesar active zones to program and to conduct log term research on data analysis and processing on strong motion for the development of Indonesia’s attenuation, and to identify the impact of any basin structure on quake vibrations in settlement areas. Follow up of this mapping is being prepared. Circular Letter of the Ministry of Public Works on nation-wide application especially for guidelines in infra-structure planning and planning of quake-proof settlements.

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