Presentation on theme: "Slovenian National Building and Civil Engineering Institute"— Presentation transcript:
1 Slovenian National Building and Civil Engineering Institute ASSESSMENT OF DAMAGE AND USABILITY OF EARTHQUAKE-DAMAGED BUILDINGS: EXPERIENCE OF SLOVENIAMiha TomaževičSlovenian National Building and Civil Engineering InstituteMilica SlokarAdministration of Civil Protection and Disaster Relief of the Republic of Slovenia
2 Seismic risk in Slovenia 1/3 of the population of Slovenia is concentrated in regions where earthquakes with PGA = 0,2 g and more are expected with return period of 475 years.In Ljubljana region, the most densely populated area of the country, where the basic functions of the country are concentrated, seismic hazard is even more severe.Most of the damage and casualties are due to inadequate seismic behaviour of existing buildings. The existing building stock (mainly unreinforced masonry buildings) is estimated to be almost 50% of the total.
4 Typical heritage masonry buildings in Slovenia CastlesUrban architectureRural architectureTypical heritage masonry buildings in Slovenia
5 Pre-World War II buildings Pre-1963 unreinforced masonry tower houesPre-World War II buildingsTypical pre-seismic codes masonry residential buildings in Ljubljana
6 History of seismic codes 1895: the earthquake of Ljubljana: the skyscraper of Ljubljana - base isolation1963: seismic design recommendations1964: first Yugoslav seismic code1981: revised Yugoslav seismic code1995: Eurocode 8, ENV version translated as alternative2008: Eurocode 8 mandatoryExisting buildings1978: law on seismological service1985: Yugoslav code for repair and strengthening of earthquake-damaged buildings2008: Eurocode 8-3 Assessment and strengthening of buildings mandatory
7 Experience in earthquake-damage assessment 1974: Kozjansko Region Governmental committee for damage evaluation categories of damage1976: Friuli earthquakes. Posočje Region Governmental committee for damage evaluation categories of damage, 3 categories of usability1998: Upper Posočje Region ACPDR. 5 categories of damage, 3 categories of usability. Categories of damage compatible with definitions given in EMS scale2004: Upper Posočje Region
8 Assessment of usability and damage Rapid evaluation: To assess usability of buildings and provide information regarding the safety of occupancy and assess the number of inhabitants needing temporary sheltersDetailed evaluation: To provide detailed information regarding the damage to buildings, which can be used as a basis for the assessment of damage costs
9 Pages 2 and 3 of questionnaire for usability and damage assessment
10 GIS-UJME Applications Address search, number of inhabitants calculation
11 Classification of damage to masonry buildings as defined by EMS scale Damage category 1: negligible to slight damageDamage category 2: moderate damageDamage category 3: substantial to heavy damageDamage category 4: very heavy damageDamage category 5: partial or total collapseClassification of damage to masonry buildings as defined by EMS scale
12 Classification of usability Usable buildingsTemporarily not usable buildingsUnusable buildings
13 Classification of usability Usable buildings marked greenRestriction:Building occupancy may continue without limitationDamage category 1 and 2 :Undamaged buildingsSlight structural damageModerate non-structural damage
14 Classification of usability Temporarily not usable buildings marked yellowRestriction:Occupancy may continue if the safety can be ensured by emergency safety measures. In most cases, the occupancy is not possible until the building is completely repaired and strengthenedDamage category 3:Substantial damage to structural systemHeavy non-structural damage
15 Classification of usability Unusable buildings marked redRestriction:Unusable, unsafe buildings are demolished and the debris removedDamage category 4 and 5:Heavy structural damage, very heavy non-structural damageTotal or near total collapse
16 Assessment procedureUsability Assessment Commission is usually composed of 2 experts and local guide, who assess 20 –30 buildings per day (rapid assessment).For easier identification of buildings, special municipality maps in seismic-prone areas of Slovenia have been prepared by ACPDR.Municipalities are divided into several zones, each including approximately 100buildings. Each zone is limited by naturalor physical objects (streets, rivers, etc.).
19 The case of the earthquake of Bovec of April 12, 1998 Based on the information received from local staff of Civil Defence, ACPDR immediately mobilised 25 professionals, who inspected the damaged buildings and assessed their usability according to the proposed methodologyOnly buildings with permanent residents and some cultural monuments have been included in the rapid evaluation of damage and usability. Four days have been needed to complete rapid evaluation. 952 buildings have been inspected.311 buildings have been found as temporarily not usable Among them, 1/3 have been seriously damaged, in some cases even beyond repair, and 2/3 have suffered repairable damage. More than 710 people have been temporarily moved to mobile homes, located close to their homes.
20 Experience after the earthquake of 1998 Timely and constant training of professionals, who will be mobilised in the case of an earthquake disaster, for both usability assessment and damage evaluation, is needed Otherwise, significant delays in earthquake disaster mitigation activities can be expectedTherefore, within the earthquake preparedness program of Slovenia, prepared by ACPDR, a continuous training of experts, members of committees for the assessment of damage and usability of earthquake damage buildings has been set forth
21 Experience after the earthquake of 1998 First exercise has been organized during a simulation of an earthquake disaster, carried out in Ljubljana in 1999In 2001, the members of committees for the assessment of damage and usability of earthquake damage buildings have been educated during courses organized in the ACPDR’s the training centre. In the years to follow, the knowledge has been improved by practical exercises on earthquake- damaged buildings on the siteAbout 200 professionals have been trained so far