SEISMIC RISK STUDY （English version）.doc

INCOSTAS CHILE S.A. REV.1  PAGE 34 de 33 27-03-06 REPORT ON SEISMIC RISK STUDY AND DEFINITION OF DESIGN SPECTRUM FOR THERMAL POWER PLANT IN CORONEL (PUNTA PUCHOCO AND PORT SITES) (Rev. 1) TABLE OF CONTENTS 1 INTRODUCTION 3 2 SEISMIC THREAT STUDY 3 2.1 Micro Zoning and Seismicity 4 2.1.1Identification of Seismic Sources52.1.2Micro Zoning or Discretization6 2.2 Probabilistic Analysis Model 92.2.1Occurrence Modeling92.2.2Frequency/Magnitude Ratio102.2.3Spread and Attenuation Features122.2.4Integrated Probabilistic Model132.2.5Design Philosoply13 2.3 Probabilistic Analysis Outcomes 14 2.4 Historical Seismicity / Deterministic Study 16 3 DESIGN SPECTRUM DEFINITION 20 3.1 Soil Mechanics Data 20 3.2 Seismic Design Spectrum 21 4 BIBLIOGRAPHY 25 ANNEX A SEISMIC CATALOG, SEISMIC CATALOG, GEOPHYSICS DEPARTMENT, PARTAMENTO DE GEOFíSICAUNIVERSIDAD DE CHILE.27 ANNEX B: SEISMIC CATALOG, USGS 31 1. INTRODUCTION Colbún S.A. is currently studying the development of an investment to install a future conventional Thermal Power Plant (CTCO) that use the coal as the primary fuel for a generating capacity of approx. 350MW gross to supply energy to the Chilean Electric Power Grid (SIC). Colbún has established the plant location at Bahía de Coronel, coast of the VIII Region. Consequently, as part of the basic local condition studies necessary for the development of the Engineering, Colbún has commissioned INCOSTAS the preparation of the seismic risk study and the definition of a design spectrum. This report provides a seismic risk study valid for two sites in the area of Bahía de Coronel, located some 30km to the south from Concepción. The first site is Punta Puchoco, located to a side of the current port “Jureles”, at coordinates 37.07oS and 73.17oW. The other site is located in the same bay, at a distance of around 4-5km, in the sector of Port Coronel, at coordinates 37.03oS and 73.14oW. The study consists of