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 1. The Romanian earthquake hazard and the 1977 disaster in Bucharest "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 Münich Re, 1998 indicates for Bucharest: “Large city with Mexico-city effect” “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 Event 1802, 1829, 1838, 1940, 1977, 1986, October 26 November 20 June 23 November 10 March 4 August 30 Epicentral intensity Io >9 ≥8 ≥8 9 8/9 7/8 Focus depth. km 150 109 133 Moment magnitude Mw Obs 7.9 Largest Vrancea event ever occurred 7.7 7.5 7.2 Largest seismic losses ever experienced • Number of events/century, having intensity larger than 9 and 7 Epicentral intensity (MSK) Catalogue time span, years 984 - 1900 1901 - 2000 I0≥ 9.0 1 2 I0 ≥ 7.0 10 16 Obs 20 century shows the highest seismic activity of the Vrancea source March 4, 1977 earthquake Mw = 7.7 ; h = 109 km Killed 1,578 people (1424 in Bucharest) Injured 11,221 people (7598 in Bucharest) • 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. The World Bank estimation of losses (Report 16.P-2240-RO, 1978): • Total losses in Romania : 2.05 billion USD (100%) : 1.42 (70%) Building and housing losses : 1.02 (50%) Construction losses PSHA, Probabilistic seismic hazard assessment Lungu, Demetriu, 1994-2004 1. Recurrence of Vrancea magnitude Date Moment magnitude, Mw ( Mw) 1 8.0 7.9 475 yr 10 Nov 1940 7.7 7.6 100 yr 4 March 1977 7.5 7.3 7.2 50 yr 26 Oct 1802 30 Aug 1986 Mean recurrence interval 1 1.687(M M ) w,max w 8.654 1.687M w 1 e e 1 .687(M M ) w,max w,o 1e 778 yr 356 148 108 82 50 40 2. Attenuation of Vrancea strong ground motion lnPGA 3.098 1.053M 1.000lnR 0.0005R 0.006h 0.502 w 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 2. Vulnerability (fragility) of existing building stock and Codes for earthquake resistance of buildings Quality of seismic design incorporated into existing buildings stock is modeled by four categories : Pre-code; Low-code; Moderate-code; High-code. MSK intensity, from seismic zonation map Period of construction of building before 1940 1941-1963 1964-1977 1978-1990 after 1990 VI VII VIII, Bucharest IX Precode Lowcode Moderate-high code 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: (i) 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 Vulnerability class i ii iii “Seismic risk class 1 buildings” Importance and exposure class I 1 1 II 1 2 III 2 3 IV 3 3 3 Building to be immediately retrofitted! Vulnerable residential buildings -from Ministry of Transports, Constructions and Tourism of RomaniaCity Number of vulnerable buildings Number of inhabitants Bacau 6 208.643 Barlad 6 78.786 Braila 4 232.409 Brasov 8 312.481 123+ ... 2.011.305 Buzau 1 146.926 Campina 2 40.297 Iasi 49 347.606 Roman 1 81.731 Suceava 1 118.183 Targu-Mures Vaslui 1 6 164.132 78.735 Bucharest Vulnerable school buildings -from Ministry of Education and Research of RomaniaNumber of vulnerable schools City Total Requiring technical assessment Having a technical report Having technical documents Bacau Barlad Brasov Bucharest Constanta Craiova Galati Giurgiu Iasi Pitesti Ploiesti Sibiu Vaslui 1 11 7 13 2 1 2 3 1 3 10 2 7 2 5 1 5 1 - 2 1 5 1 - 1 11 9 22 1 7 3 2 8 2 6 4 10 Total 54 23 9 86 Vulnerable hospital buildings -from Ministry of Health and Family of Romania- Number of vulnerable hospitals CITY Bacau Barlad Bucharest Buzau Constanta Craiova Focsani Galati Giurgiu Iasi Pitesti Ploiesti Sibiu Targu-Mures Vaslui Total Severely damaged. Requiring immediate technical assessment Having a technical report Approved project for retrofitting Retrofitting in work 3 13 9 7 4 21 2 2 1 2 4 68 16 6 1 17 7 47 1 3 2 45 9 7 4 2 9 1 45 9 2 1 2 5 19 146 6 2 10 2 2 1 2 5 12 Total 3. National programs and International projects for seismic risk mitigation in 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 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 ! Seismic instrumentation in Romania, 2004 Name of network INCERC & ISC, State Inspectorate for New digital Construction networks, installed in CNRRS & JICA, 2003 Japan International Cooperation Agency 1 Project Existing seismic networks, in 2002 TOTAL instruments Bucharest Romania (including Bucharest) 7 ETNA 31 ETNA 11 K2 16 instruments: -11 K2; - 5 ETNA INCERC 21 instruments: -10 SMA-1 (analog) - 9 ADS (digital) -2 digital stations for continuous monitoring 70 instruments: -58 SMA-1(analog) - 9 ADS (digital) 3 digital station for continuous monitoring INFP/SFB 461 German Science Foundation Project at University of Karlsruhe 15 K2 41 K2 54 digital instruments 158 instruments 100 digital 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 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. • Project duration: 5 yr 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 for strong ground motion observation 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) Seismic network Free field outside Bucharest ETNA 6 sites Borehole Bucharest K2 7 sites 3 sensors (surface + 2 in borehole) Building Bucharest K2 4 sites Borehole seismic instrumentation Surface and borehole cables Altus K2 accelerometer Shallow borehole 24÷30m Borehole sensor Borehole sensor Deep borehole 60÷153m Free field 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 Objective 2 - Europe inventory database and typology Classification of buildings occupancy Code Occupancy category Importance & exposure category 1 B B1 1.1 1.2 1.3 1.4 1.5 1.6 B2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 B3 3.1 3.2 3.3 3.4 GENERAL BUILDING STOCK Residential Single family dwelling (house) Multi family dwelling (apartment bldg.) Low-rise (1-2) Mid-rise (3-7) High-rise (8+) Institutional dormitory Commercial Supermarkets, Malls Offices Services Hotels, Motels Restaurants, Bars Parking Warehouse Cultural Museums Theatres, Cinemas Public event buildings Stadiums 2 3 x x1) x1) x2) x2) x x x x x2) x x x x x x x x3) x2) x2) x2) x x x x 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 Building typology matrix, BTM Label RC Height description Name No. of stories Low-rise Mid-rise High-rise Low-rise Mid-rise High-rise 1-3 4-7 8+ 1-3 4-7 8+ h9 9 < h 21 h > 21 h9 9 < h 21 h > 21 Code level* Height h, N L M H m Reinforced concrete structures RC1 Concrete moment frames RC2 Concrete shear walls RC3 Concrete frames with unreinforced masonry infill walls Regularly infilled frames Low-rise Mid-rise High-rise 1-3 4-7 8+ h9 9 < h 21 h > 21 Irregularly frames (i.e., irregular structural Low-rise system, irregular infills, soft/weak story) Mid-rise High-rise 1-3 4-7 8+ Low-rise Mid-rise High-rise Precast Concrete Tilt-Up Walls Low-rise Mid-rise High-rise Precast Concrete Frames with Concrete Low-rise shear walls Mid-rise High-rise 1-3 4-7 8+ 1-3 4-7 8+ 1-3 4-7 8+ h9 9 < h 21 h > 21 h9 9 < h 21 h > 21 h9 9 < h 21 h > 21 h9 9 < h 21 h > 21 3.1 3.2 RC4 RC5 RC6 *Code level Building type description RC Dual systems (RC frames and walls) 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) Comparative study for 7 towns I. Population and Building exposure Population and yearly GDP Town Barcelona Bitola Bucharest Catania Nice Sofia Thessaloniki Inhabitants 1,503,451 79,456 2,011,305 333,075 342,738 1,133,183 1,048,151 Population density, persons/km2 15,176 12,600 10,806 6,125 4,766 4,680 21,600 Population growth, 20th century* 1970 1990 1989 1971-1991 1980 1985 1991 GDP/person (approx.) Euro 22,000 1,620 1,980 9,000-15,000 20,000 1,630 15,290 Population of the 7 towns 2,500,000 2,000,000 WP1. UTCB 1,500,000 Population 1,000,000 500,000 0 Barcelona Bitola Bucharest Catania Nice Sofia Thessaloniki Population density in the 7 towns 25,000 20,000 Population density, persons/km2 WP1. UTCB 15,000 10,000 5,000 0 Barcelona Bitola Bucharest Catania Nice Sofia Thessaloniki Number of buildings for the 7 towns 120,000 100,000 WP1. UTCB 80,000 Number of buildings 60,000 40,000 20,000 NA 0 Barcelona Bitola Bucharest Catania Nice Sofia NA Thessaloniki Number of housing units for 7 towns 900,000 800,000 WP1. UTCB 700,000 600,000 Number of housing units 500,000 400,000 300,000 200,000 100,000 0 Barcelona Bitola Bucharest Catania Nice Sofia Thessaloniki II. Earthquake hazard and earthquake instrumentation 10.5 10.5 9.5 LARGEST HISTORICAL EVENT 20th CENTURY 9.5 WP1. UTCB WP1. UTCB 8.5 8.5 7.5 7.5 6.5 6.5 5.5 5.5 4.5 4.5 NA 3.5 Barcelona 3.5 Bitola Bucharest Catania Nice Sofia Thessaloniki Barcelona Bitola Bucharest Catania Nice Sofia Thessaloniki MSK local-intensity of largest experienced earthquake for the 7 towns III. Vulnerability and typology of European buildings stock Building stock age in the 7 towns versus Seismic codes inter-benchmark periods Town Seismic codes inter-benchmark periods Pre-code Low-code Moderate code Barcelona 79% 21% -- Bitola 48% 29% 23% Bucharest 30% 30% 40% Catania 92% - 8% Nice 75% Sofia Thessaloniki 25% Data not available 20% 50% 30% Buildings typology Masonry buildings types for the 7 towns Town Masonry structures, M 1.1 Barcelona Bitola Bucharest Catania Nice Sofia Thessaloniki 1.2 1.3 2 3.1 3.2 3.3 Wood 3.4 4 5 1 World Bank project in Romania Component A: Strengthening of Disaster management capacity ~5% 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 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 In Bucharest Emergency bldg 12 Hospitals bldg 13 Educational bldg 6 Important public bldg 6 Essential facilities Total 37 Type of buildings In seismic counties of Romania 18 9 6 14 47 Total 30 22 12 6 14 84 The buildings list is splitted in two lists: priority list and additional list. Priority list of buildings contains 65 buildings i.e: In In seismic counties Bucharest of Romania Emergency bldg 11 187 Hospitals bldg 12 7 Educational bldg 6 6 Important public bldg 6 Total 35 30 Type of buildings Total 28 19 12 6 65 Distribution of buildings with occupancy Public 12% Educational 18% Emergency facilities 30% Communication 26% Emergency facilities 39% Public 4% Educational 11% Hospitals 40% Hospitals 20% Bucharest Other cities Distribution of number of buildings to be retrofitted Distribution of cost for buildings to be retrofitted Other cities 33% Bucharest 38% Other cities 62% Bucharest 67% Distribution of buildings with number of stories 60 60 Bucharest 50 Number of buildings Number of buildings 50 40 30 20 10 0 Other cities 40 30 20 10 5 8 Number of stories 0 5 8 Number of stories Distribution of buildings with floor area 15 15 Other cities 10 30 00 > 30 00 25 00 250 500 1000 1500 2000 2500 3000 Total floor area, m² 20 00 0 15 00 >3 00 0 30 00 25 00 20 00 15 00 10 00 50 0 250 500 1000 1500 2000 2500 3000 Total floor area, m² 10 00 0 5 50 0 5 <2 50 Number of buildings 10 <2 50 Number of buildings Bucharest Distribution of buildings with year of construction 18 18 59% 14 14 12 12 10 56% 16 Number of buildings 41% 8 6 4 40% 10 8 6 4 4% 2 2 No code ... P13-63 P100-78 P100-92 0 Year of constr. Building code 1900 1940 1963 1978 1992 19 40 19 63 :P 13 -6 3 19 78 :P 10 078 19 92 :P 10 092 19 63 :P 13 -6 3 19 78 :P 10 078 19 92 :P 10 092 Building code 1900 1940 1963 1978 1992 19 40 <1 90 0 0 Year of constr. <1 90 0 Number of buildings 16 No code ... P13-63 P100-78 P100-92 Distribution of buildings with present seismic intensity map 90 80 77 Number of buildings 70 60 50 40 30 20 10 0 9 1 VII VIII IX Seismic intensity 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.