Reconstruction of earthquake-damaged buildings in the City of Zagreb and its surroundings

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The devastating earthquake that hit Zagreb and its surroundings in the early hours of 22 March 2020 caused great damage to buildings - family houses, residential buildings, hospitals, schools, urban roads. Several institutions have been involved in addressing this complex problem and each of them helps within its competences and capabilities.

Immediately after learning about the severe consequences of the devastating earthquake through the civil protection system of the City of Zagreb, contact was established with the professional chambers of civil engineers, the competent inspection and the Faculty of Civil Engineering in order to examine the safety of buildings at the soonest and to enable people to safely return to their homes where possible.

The city's Emergency Management Office provided an online application through which citizens can report a building for inspection of damage caused by the earthquake. Upon filling in the questionnaire, the building is entered in the database for examination of earthquake damages, and its conditions are determined by structural engineers organized by the Civil Protection Headquarters, who are also the only ones responsible for the inspection and who work following the form created for the assessment of damage. For those whose houses have suffered so much damage that they are not safe for their stay, temporary accommodation and a warm meal in the Cvjetno naselje student hall of residence. Experts on the ground are making great efforts and risking their health due to the current COVID-19 outbreak in order to visit all of these reported buildings and determine the degree of damage. home are provided to the flower village. Zagreb's crisis headquarters urged those whose buildings were severely damaged in the earthquake to report to a special phone line to have adequate assistance providedas soon as possible. The city opened the free number 0800 8805 where citizens affected by the earthquake can receive aid.

Experts on the ground are making great efforts and risking their health due to the current COVID-19 outbreak in order to visit all of these reported buildings and determine the degree of damage. Experts who are on the ground are making great efforts and risking their health due to the current COVID-19 outbreak in order to visit all of these reported buildings and to determine the threat posed by the damage. Through joint and intensive efforts with the City of Zagreb and other stakeholders, we are doing everything to ensure the conditions for structural engineers to complete their building inspection work as soon as possible, whereupon data on the total number of unusable buildings and the number of buildings to be demolished or rehabilitated will be available. By 29 April, 15,600 buildings out of the reported 18,000 were examined.

"I thank all those who made themselves available and work day and night to ensure the safety of citizens, and then the repair of facilities and the return of citizens to their homes. All this is co-ordinated by professor Josip Atalić of the Faculty of Civil Engineering in Zagreb, together with staff of the Headquarters, the Ministry, the chamber of civil engineers...” – minister Štromar said.


Intense work at bill drafting

The Ministry of Construction and Physical Planning is in charge of drafting a law that will provide a legal framework for and enable the reconstruction of earthquake-damaged buildings and houses, and its drafting commenced a day after the earthquake. Work is intense, and the bill has already been drafted. Two sessions for drafting the bill have been held so far, on 31 March and 07 April, and in the meantime two meetings of Expert working groups were held: on 8 April a meeting of the Working group for rehabilitation and reconstruction of chimneys, and on 9 April a meeting of the Working group for the title and content of the design documents was held.

In the bill, facilities are divided into three categories: family houses, residential buildings, which are mainly located in Zagreb's upper town and downtown, and public buildings. In privately owned multiapartement buildings, it was established that they should be provided with better statics in order to resist even stronger earthquakes than the recent one. Without building on the basis of a quality structural design and raising the level of building stability, no reconstruction can be done, and we are discussing how and under what conditions experts will develop these designs. As for family houses, we are planning to rehabilitate those where this is feasible or to build new ones. The specificity of the entire situation is that a large number of facilities are under heritage protection and that this part of the reconstruction is coordinated with the Ministry of Culture.

We envisage that the bill will soon be ready for public consultations, and we have included representatives of the profession already at this stage in order to have a bill with the highest degree of agreement achieved among various professions. Thereupon the bill shall undergo public consultations in order to inform citizens of the provisions and objectives of this act and to enable them to submit their proposals to be considered.


Preliminary damage assessment

On 23 April, professor Josip Atalić of the Faculty of Civil Engineering presented a preliminary assessment of the post-earthquake reconstruction of Zagreb and its surroundings of about EUR 5.6 billion involving a complete reconstruction, up to the level of currently applicable earthquake resistance standards, for hospitals and educational institutions only, whereas the cost of such reconstruction of all damaged facilities would amount to about EUR 13.3 billion.

If only the necessary “cosmetic” measures were to be taken, the total cost of reconstruction would be slightly less than EUR 1.2 billion. This was the starting point for the development of a total of seven cost assessment variants, and it was finally decided that optimal would be the one according to which the total direct financial damage was estimated at about EUR 5.6 billion, or approximately HRK 42 billion. On the other hand, if all damaged buildings were to be reinforced to the level of today's regulations, that would cost EUR 13.3 billion.

The renovation modes include four levels that are also found in the proposed version of the reconstruction act.

The first level includes the repair of non-structural elements, which assumes that the load-bearing structures of buildings after the earthquakes is without damage or with very small damages, and refers to certain minor repairs of the roofing, partition walls, chimneys, etc.

The second level, which would include multiapartment buildings and family houses, includes repair or replacement of earthquake-damaged structural parts, with some improvements made to the building structure as a whole, with the aim of achieving the minimum original resistance, preferably also reinforcement, and satisfies the level of about half of the current regulations in force.

The third level refers to reinforcement of the structure which increases the resistance to earthquake action to a level of about 75 percent of existing regulations and standards, and includes public buildings, such as cultural, religious and sports facilities.

Finally, the fourth level implies overall reconstruction, i.e. meeting the earthquake resistance level prescribed by the applicable standards, and refers to the most vital public buildings, such as hospitals, schools, kindergartens and faculties.


Reconstruction of buildings

Organised building reconstruction will begin after the adoption of the Rehabilitation Act and Programme. Before the reconstruction begins, it is necessary to develop designs for the works and to contract their execution.

The aim is to enable citizens to return to their homes as soon as possible, where possible, and to restore the city in accordance with all the rules and standards required by the profession and to ensure transparent spending of funds. The consequences of the earthquake are devastating, and reconstruction will be complex, which is why we have started establishing a legal framework that will provide the best response to the situation we have found ourselves in. The reconstruction will take years, but there are urgent works. Many have remained without heating and hot water preparation due to damaged chimneys, and one of our goals is also to help through co-financing.

Some citizens want to independently and immediately start reconstruction works, what they of course can, and we are working at legally enabling the recovery of funds for all those projects that will be carried out according to the rules of the profession.
Until the Reconstruction Act is passed, there are regulations in force so that citizens can begin reconstruction even now. Several days after the earthquake, the Ministry sent a letter to the building managers urging the managers to take all actions, from design preparation onward, especially for emergency rehabilitation.

The currently valid building regulations enable removal of earthquake consequences that reduced or threatened the serviceability of buildings by performing extraordinary maintenance works in such a way that appropriate equivalent replacement parts are used for parts of buildings and equipment, devices and installations damaged by an emergency event. According to the existing law, it is possible to replace the roofing without the need to develop a design, whereas replacement of the roof structure, walls, pillars or flue gas ducts shall be carried out exclusively on the basis of a design made by certified persons. Certified civil engineers are responsible for structures, while certified civil engineers and certified mechanical engineers are competent for chimneys. For an overall reconstruction of earthquake-damaged buildings and improvement of their resistance to earthquake action, it is necessary to develop a special design.


Chimney rehabilitation

Chimneys must be thoroughly examined and their correctness for further use must be determined by chimney sweepers.

Chimney rehabilitation cannot be standardised and each chimney should be viewed separately. Authorised mechanical and civil engineers will provide solutions depending on the structure, position and condition of the chimney.

In accordance with the currently valid building regulations, the replacement of the flue duct is carried out exclusively on the basis of a design developed by certified persons (certified mechanical engineer and certified civil engineer). This procedure is defined in detail in the Technical regulation on chimneys in construction works (Official Gazette 3/07), where apart from the professions involved, the content of the chimney design is prescribed in detail, as well as technical characteristics and other requirements for construction products intended for installation into chimneys. Certified civil and mechanical engineers have the necessary expertise to apply this technical regulation in each specific situation.

Therefore, the aspect of the chimney building element is prescribed in detail in the Technical regulation on chimneys (Official Gazette 3/07) which is within the competence of this Ministry, while the aspect concerning its functionality in thermotechnical terms is prescribed by the Act on Flammable Liquids and Gases (Official Gazette 108/95, 56/10) which is within the competence of the Ministry of the Interior, where the chimney is part of the gas installation.

The model of co-financing the purchase of condensation chimneys is being discussed with the Ministry of Environment and Energy. Talks on co-financing individual reconstruction projects are also under way with the World Bank.


Damage reporting

Ured za gospodarstvo grada Zagreba objavio je Poziv za prijavu štete oštećenika potresa. Obrazac PN se može preuzeti na www.zagreb.hr ili u pisarnicama Gradske uprave. Kako se navodi na stranicama Grada Zagreba  prijava štete na imovini se obavlja radi upisa u registar šteta kako bi se nakon prijave štete moglo pristupiti procjeni temeljem koje bi se realno procijenila vrijednost imovine na kojoj je nastala šteta i procijenila šteta koja se dogodila toj imovini, a temeljem čega bi se utvrdio iznos pomoći za ublažavanje i djelomično uklanjanje posljedica prirodnih nepogoda sukladno Zakonu  o ublažavanju i uklanjanju posljedica prirodnih nepogoda. Sve potrebne informacije oko obrazaca mogu se dobiti na besplatni broj telefona 0800 88 03 i na e-mail: prijavastetepotres@zagreb.hr

Zagreb's City Office for Economy announced a Call for damage reporting by those who have suffered earthquake damages. The PN form can be downloaded at www.zagreb.hr or at the registry offices of the City administration. As indicated on the web site of the City of Zagreb, property damage reports are made for registration in the damage register so that after the damage report an assessment can be made on the basis of which the value of the property on which the damage occurred would be realistically assessed and damage that occurred to that property assessed, based on which the amount of aid for mitigation and partial elimination of consequences of natural disasters would be determined in accordance with the Act on Mitigation and Removal of Natural Disaster Consequences. All necessary information about the forms can be obtained by free calls to the phone number 0800 88 03 and by e-mail: prijavastetepotres@zagreb.hr

After preliminary assessment of the damage to construction works, for all additional issues citizens can contact the Sector for construction and repair of damaged social activity facilities and of housing facilities, Ulica grada Vukovara 58b, first floor, room 106, Phone: 01/6100-921; 01/6100-709, e-mail: obnovazgrada@zagreb.hr

In order to record damaged apartments and business premises owned by the Republic of Croatia, the Ministry of State Property developed the MDI application.

On 26 March 2020, the Ministry invited construction companies and construction material shops to participate in emergency rehabilitation with their own donations.

The organized distribution of construction materials for emergency rehabilitation is also carried out by the City of Zagreb, and the notification of the manner and conditions of taking over construction materials for necessary assistance to persons affected by earthquakes is published on the city's website.

Organiziranu podjelu građevinskog materijala za hitnu sanaciju provodi i Grad Zagreb a obavijest o načinu i uvjetima preuzimanja građevinskog materijala za nužnu pomoć osobama pogođenim potresom objavljena je na web stranici grada.

The organized distribution of construction materials for emergency rehabilitation is also carried out by the City of Zagreb, and the notification of the manner and conditions of taking over construction materials for necessary assistance to persons affected by the earthquake is published on the city's website.


  

  

  

  

 

Photos: HINA