Presentation Transcript

Hazard Risk Mitigation in Europe and Central Asia WORLD BANK Workshop Istanbul, October 26-28, 2004 Seismic risk mitigation in the Vrancea region, Romania Dan Lungu Technical University of Civil Engineering, Bucharest and National Institute for Building Research, Bucharest Original Presentation has been modified for Internet Use. Contents 1. The Romanian earthquake hazard and the 1977 disaster in Bucharest 2. Vulnerability (fragility) of existing building stock and Codes for earthquake resistance of buildings 3. National programs and international projects for seismic risk mitigation in Romania "Nowhere else in the world is a center of population so exposed to earthquakes originating repeatedly from the same source" Charles Richter. 15 March 1977, Letter to the Romanian government World Map of Natural Hazards prepared by the M�nich Re, 1998 indicates for Bucharest: �Large city with Mexico-city effect� 1. The Romanian earthquake hazard and the 1977 disaster in Bucharest �The unusual nature of the ground motion and the extent and distribution of the structural damage have important bearing on earthquake engineering efforts in the United States.� Jennings & Blume, NRC & EERI Report 1000 yr catalogue of Vrancea earthquakes Major historical events and major 20 century earthquakes Number of events/century, having intensity larger than 9 and 7 Destroyed or seriously damaged 33,000 housing units and caused lesser damage to 182,000 other dwellings Destroyed 11 hospitals and damaged 448 others hospitals, etc. March 4, 1977 earthquake Mw = 7.7 ; h = 109 km Killed 1,578 people (1424 in Bucharest) Injured 11,221 people (7598 in Bucharest) The World Bank estimation of losses (Report 16.P-2240-RO, 1978): Total losses in Romania : 2.05 billion USD (100%) Construction losses : 1.42 (70%) Building and housing losses : 1.02 (50%) PSHA, Probabilistic seismic hazard assessment Lungu, Demetriu, 1994-2004 1. Recurrence of Vrancea magnitude 2. Attenuation of Vrancea strong ground motion PGA - peak ground acceleration at the site Mw- moment magnitude: Mw,0 = 6.3 Lower threshold magnitude; Mw, max= 8.1 Max credible R - hypocentral distance to the site; h - focal depth; ?ln PGA= 0.502- standard deviation of lnPGA Database: 80 triaxial records at 48 free-field stations in Romania, R. of Moldavia, Bulgaria Quality of seismic design incorporated into existing buildings stock is modeled by four categories : Pre-code; Low-code; Moderate-code; High-code. 2. Vulnerability (fragility) of existing building stock and Codes for earthquake resistance of buildings 3 International lessons unlearnt from the 1977 earthquake 1 �A systematic evaluation should be made of all buildings in Bucharest erected prior to the adoption of earthquake design requirements and a hazard abatement plan should be developed.� From: �Observation on the behaviour of buildings in the Romanian earthquake of March 4, 1977� by G. Fattal, E. Simiu and Ch. Cluver. Edited as the NBS Special Publication 490, US Dept of Commerce, National Bureau of Standards, Sept 1977. 2 �Tentative provisions for consolidation solutions would preferably be developed urgently�. From: �The Romanian earthquake. Survey report by Survey group of experts and specialists dispatched by the Government of Japan (K. Nakano). Edited by JICA, Japan International Cooperation Agency, June 1977. 3 �Bucharest had been microzoned as part of UNESCO Balkan Project, with microzones denoting three levels of risk. The worst destruction occurred in lowest-risk microzone.� From: ��Earthquake in Romania March 4,1977. An Engineering Report� by G. Berg, B. Bolt, M. Sozen, Ch. Rojahn. Edited by National Academy Press, Washington, D.C. 1980 The 1977 National strategy for strengthening damaged buildings �The retrofitting of buildings must provide: For the old buildings � the same resistance the have before 1940 earthquake (when they survived!); (ii) For the new buildings � the same resistance the have when they were designed� Letter to the Municipality of Bucharest of the General Inspector for Construction of Romania, based on March 30, 1977, Order of Romanian Government �Retrofitting of the buildings damaged by the 1977 earthquake will consist of strict local repairing of damaged elements. Additional measures for seismic protection are not allowed.� Letter to the technical University of Civil Engineering, Bucharest from General Inspector for Construction of Romania and General Director of Central Institute for Research Design and Coordinator for Construction, July 11, 1977 Seismic risk class Matrix �Seismic risk class 1 buildings� Building to be immediately retrofitted! Vulnerable residential buildings -from Ministry of Transports, Constructions and Tourism of Romania- Vulnerable school buildings -from Ministry of Education and Research of Romania- Vulnerable hospital buildings -from Ministry of Health and Family of Romania- Objectives: 1. Strengthening of �seismic risk class 1� buildings: Legislation + Construction work; 2. Upgrading of the code for seismic design of buildings and structures; 3. Seismic instrumentation 3. National programs and International projects for seismic risk mitigation in Romania Strengthening work for the 123 highly vulnerable buildings in Bucharest October 2004: 3 buildings are fully retrofitted 8 buildings are under retrofitting 16 buildings have retrofitting projects ready 8 buildings are on the waiting list for retrofitting Upgrading the code for seismic design of buildings and structures The draft of the New code for earthquake resistance of new structures, P100-2004, following EUROCODE 8 format, was just issued (Jan 2004) The draft of the New code for earthquake resistance of existing buildings and structures: to be prepared ! Existing seismic networks, in 2002 INFP/SFB 461 German Science Foundation Project at University of Karlsruhe 15 K2 41 K2 TOTAL 54 digital instruments 158 instruments instruments 100 digital Seismic instrumentation in Romania, 2004 JICA technical cooperation project : �Reduction of seismic risk for buildings and structures in Romania� Project signed in 2002, when 100 years of diplomatic relations between Japan and Romania were celebrated Project duration: 5 yr JICA Project in Romania is based on partnership of 3 institutions: NCSRR, National Center for Seismic Risk Reduction UTCB, Technical University of Civil Engineering Bucharest INCERC, National Institute for Building Research, Bucharest under the authority of: MTCT, Ministry of Transports, Constructions and Tourism. Total cost of the project 5.27 mill. USD Equipment cost 2.7 mill. USD: - Soil testing laboratory - Structure testing laboratory - Seismic instrumentation network in Bucharest and Romania (free field, borehole, buildings) 16 Romanian young students/engineer to be trained in Japan 34 Japanese short term and long term experts in Romania Equipments for soil testing and investigation Triaxial testing equipment Drilling equipment SPT/CPT testing equipment Equipment delivered by JICA and installed together with two OYO technicians and one Japanese expert: - Altus K2 accelerometer (11) - borehole sensors FBA-23DH (14+1) - sensors EPISENSOR ES-T (9+1) - ETNA accelerometer (5+1) Equipment for strong ground motion observation Borehole seismic instrumentation Bucharest - Location of borehole instrumented sites Instrumented buildings in Bucharest RISK U.E. Project An advanced approach to earthquake risk scenarios with applications to different European towns Flow charts of RISK UE Project (P. Mouroux) Workpackage 1 of RISK-UE European distinctive features, inventory database and typology Objective 1 - Distinctive features of European towns Town identity Population characteristics Urbanised area and elements at risk Impact of past earthquakes on elements at risk Strong motion data in the city and seismic hazard Geological, geophysical and geotechnical information Evolution of earthquake resistant design codes Earthquake risk management efforts References Classification of buildings occupancy 1) Buildings with capacity greater than 150 people 2) Buildings with capacity greater than 300 people or where more than 300 people congregate in one area Objective 2 - Europe inventory database and typology Building typology matrix, BTM *Code level N - no code; L - low-code (designed with unique arbitrary base shear seismic coefficient); M - moderate-code; H - high-code (code comparable with Eurocode 8) Population and yearly GDP I. Population and Building exposure Comparative study for 7 towns Population Population of the 7 towns Population density, persons/km2 Population density in the 7 towns Number of buildings Number of buildings for the 7 towns Number of housing units Number of housing units for 7 towns MSK local-intensity of largest experienced earthquake for the 7 towns II. Earthquake hazard and earthquake instrumentation Building stock age in the 7 towns versus Seismic codes inter-benchmark periods III. Vulnerability and typology of European buildings stock Masonry buildings types for the 7 towns Buildings typology World Bank project in Romania Component B: Earthquake Risk Reduction ~35% Subcomponents: Strengthening of high priority buildings and lifelines Design & supervision Building code review and study of code enforcement Professional training in cost effective retrofitting Component A: Strengthening of Disaster management capacity ~5% Components C D& E: Flood, Pollution & Project Management 60% Implementation unit for Component B at MTCT, Ministry of Transports, Construction and Tourism Romanian Government has been approved the following list of buildings to be retrofitted on April 7, 2004 The buildings list is splitted in two lists: priority list and additional list. Priority list of buildings contains 65 buildings i.e: Distribution of buildings with occupancy Distribution of number of buildings to be retrofitted Distribution of cost for buildings to be retrofitted Distribution of buildings with number of stories Distribution of buildings with floor area Distribution of buildings with year of construction Distribution of buildings with present seismic intensity map 1 77 9 0 10 20 30 40 50 60 70 80 90 7 8 9 Seismic intensity Number of buildings VII VIII IX MSK World Bank report �Preventable Losses: Saving Lives and Property through Hazard Risk Management� Strategic Framework for reducing the Social and Economic Impact of Earthquake, Flood and Landslide Hazards in the Europe and Central Asia Region Draft, May 2004 Romania is regarded as one the most seismically active countries in Europe Bucharest is one of the 10 most vulnerable cities in the world. Recommendations for Romania: Upgrade the legal framework for hazard specific management; Review the existing buildings code for the retrofitting of vulnerable buildings; Conduct a comprehensive public awareness campaign for the earthquake risk; Invest in hazard mitigation activities in order to reduce the risks caused by earthquakes; Develop financing strategy for catastrophic events.