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| reports:report_83 [2025/11/10 20:36] – m.baiguera | Changed string Earthquakes [2025/11/13 09:18] (current) – created minor |
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| **Last Updated:** | **Last Updated:** |
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| **Regions Where Found:** Buildings of this construction type can be found in all major urban areas in the country. This type of housingconstruction is commonly found in urban areas. | **Regions Where Found:** Buildings of this construction type can be found in all major urban areas in the country. This type of housing construction is commonly found in urban areas. |
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| **Summary:** This multi-family urban housing construction was practiced in Romania between the 1960s and 1990s. The load-bearing system is a precast reinforced concrete large panel construction.Buildings of this type are typically highrises (10or 11 stories high), although there are also low to medium-rise buildings (4 to 8 stories high) of this construction type (with different structural details). In general, buildings of this type are of rectangular plan, with honeycomb ("fagure") layout, housing typically four apartments per floor. Wall panels are laid in both the longitudinal and the transverse direction. The panels are mechanically coupled at the base, with continuous vertical reinforcement bars.This region is well known as a seismically prone area, with the epicentre of damaging earthquakes close to Vrancea. Earthquakes with the Richter magnitude of over 7.0 occur on average every 30 years. Bucharest, the capital, is located around 150 km south of the epicentre and lies in the main direction of the propagation of seismic waves. The Bucharest area is located on the banks of the Dmbovita and Colentina rivers, on non homogenous alluvial soil deposits.During the earthquake of 4 March 1977 (Richter magnitude 7.2), over 30 buildings collapsed inBucharest, killing 1,424 people. There was no significant damage reported to the buildings of this construction type in the 1977 earthquake.Consequently, this construction technique has continued to be practiced since the earthquake.The building described in this report was builtafter the 1977 earthquake, and has not been exposed to damaging earthquakes so far. | **Summary:** This multi-family urban housing construction was practiced in Romania between the 1960s and 1990s. The load-bearing system is a precast reinforced concrete large panel construction.Buildings of this type are typically highrises (10or 11 stories high), although there are also low to medium-rise buildings (4 to 8 stories high) of this construction type (with different structural details). In general, buildings of this type are of rectangular plan, with honeycomb ("fagure") layout, housing typically four apartments per floor. Wall panels are laid in both the longitudinal and the transverse direction. The panels are mechanically coupled at the base, with continuous vertical reinforcement bars.This region is well known as a seismically prone area, with the epicentre of damaging earthquakes close to Vrancea. Earthquakes with the Richter magnitude of over 7.0 occur on average every 30 years. Bucharest, the capital, is located around 150 km south of the epicentre and lies in the main direction of the propagation of seismic waves. The Bucharest area is located on the banks of the Dmbovita and Colentina rivers, on non homogenous alluvial soil deposits.During the earthquake of 4 March 1977 (Richter magnitude 7.2), over 30 buildings collapsed inBucharest, killing 1,424 people. There was no significant damage reported to the buildings of this construction type in the 1977 earthquake.Consequently, this construction technique has continued to be practiced since the earthquake.The building described in this report was builtafter the 1977 earthquake, and has not been exposed to damaging earthquakes so far. |
| ==== 2. Features ==== | ==== 2. Features ==== |
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| {{gallery>:reports:report_83?rp83_features_*.jpg&200x200&lightbox&crop&4 | }} | {{gallery>:reports:report_83?rp83_features_*.jpg&1200x1200&lightbox&crop&4}} |
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| **Plan Shape:** Rectangular, solid | **Plan Shape:** Rectangular, solid |
| **Type of Structural System:** Structural Concrete: Precast Concrete: Shear wall structure with precast wall panel structure | **Type of Structural System:** Structural Concrete: Precast Concrete: Shear wall structure with precast wall panel structure |
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| **Additional comments on structural system:** This building type is characterized by a so-called "honeycomb" ("fagure" in Romanian) building plan characteristic for Romanian housing design - the same system is described for the "OD" housing type(World Housing Encyclopedia Report 78). It consists of box-type units creating rooms. Due to such a building configuration, the walls are well connected and are able to carry the loads in a uniform manner.Floor structures are 120 mm thick reinforced concrete solid slabs supported by the load bearing walls.Typical wall-floor connection is illustrated in Figure 13. These buildings are supported by mat foundations.The basement walls are cast-in-place.The special feature of the building described in this report is that the facade walls are non-load bearing structures of lightweight block masonry construction. In some buildings of this construction type, precast concrete wall panels are used as facade elements. The interior wall panels are of solid concrete construction - in this case, there is no need for a 3-layered panel section with thermal insulation in the middle (typical for the facade wall panels).The load-bearing walls are laid in two principal directions, as illustrated in Figure 9. In general, there are two interior walls in the longitudinal direction and nine walls in the transverse direction; it should be noted that four transverse walls are continuous over the building width, whereas the other five walls are shorter.In addition, there are lightweight concrete partition walls, some of which have been removed in building renovations carried out by owners. The main lateral load-resisting structure consists of 200 mm precast reinforced concrete wall panels supported by RC slabs (walls in pre-1977 buildings are typically 140 mm thick). The wall panels form a box of room size ("panouri mari"). The lateral stability is provided by the columns tied to the wall panels, as illustrated in an example of corner panels, see Figure 12. Boundary elements are used instead of the columns as "stiffening" elements at the exterior (as shown in Figure 10). According to NBS (1977), the mechanical union of wall panels in the joints is achieved by means of splice bars welded to the transverse reinforcement of adjacent panels. Longitudinal bars, used singly in vertical joints and in pairs in horizontal joints, provide an added bearing area for the transfer of tension across the connections. The coupling of the floor panels is somewhat different, as illustrated in Figure 15. The top bars are splice welded while the bottom bars are bent up 90 degrees and lapped. This particular scheme gives greater continuity to the floors at the supports than the lapped loop arrangement used in the high-rise building system. The wall panels are mechanically coupled at their base, as illustrated in Figure 16, so that all vertical bars are continuous across the horizontal joints (it should be noted that in the case of the high-rise building panel connections only the longitudinal bars of vertical joints are coupled). | **Additional comments on structural system:** This building type is characterized by a so-called "honeycomb" ("fagure" in Romanian) building plan characteristic for Romanian housing design - the same system is described for the "OD" housing type (World Housing Encyclopedia Report 78). It consists of box-type units creating rooms. Due to such a building configuration, the walls are well connected and are able to carry the loads in a uniform manner.Floor structures are 120 mm thick reinforced concrete solid slabs supported by the load bearing walls.Typical wall-floor connection is illustrated in Figure 13. These buildings are supported by mat foundations.The basement walls are cast-in-place.The special feature of the building described in this report is that the facade walls are non-load bearing structures of lightweight block masonry construction. In some buildings of this construction type, precast concrete wall panels are used as facade elements. The interior wall panels are of solid concrete construction - in this case, there is no need for a 3-layered panel section with thermal insulation in the middle (typical for the facade wall panels).The load-bearing walls are laid in two principal directions, as illustrated in Figure 9. In general, there are two interior walls in the longitudinal direction and nine walls in the transverse direction; it should be noted that four transverse walls are continuous over the building width, whereas the other five walls are shorter.In addition, there are lightweight concrete partition walls, some of which have been removed in building renovations carried out by owners. The main lateral load-resisting structure consists of 200 mm precast reinforced concrete wall panels supported by RC slabs (walls in pre-1977 buildings are typically 140 mm thick). The wall panels form a box of room size ("panouri mari"). The lateral stability is provided by the columns tied to the wall panels, as illustrated in an example of corner panels, see Figure 12. Boundary elements are used instead of the columns as "stiffening" elements at the exterior (as shown in Figure 10). According to NBS (1977), the mechanical union of wall panels in the joints is achieved by means of splice bars welded to the transverse reinforcement of adjacent panels. Longitudinal bars, used singly in vertical joints and in pairs in horizontal joints, provide an added bearing area for the transfer of tension across the connections. The coupling of the floor panels is somewhat different, as illustrated in Figure 15. The top bars are splice welded while the bottom bars are bent up 90 degrees and lapped. This particular scheme gives greater continuity to the floors at the supports than the lapped loop arrangement used in the high-rise building system. The wall panels are mechanically coupled at their base, as illustrated in Figure 16, so that all vertical bars are continuous across the horizontal joints (it should be noted that in the case of the high-rise building panel connections only the longitudinal bars of vertical joints are coupled). |
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| **Gravity load-bearing & lateral load-resisting systems:** | **Gravity load-bearing & lateral load-resisting systems:** |
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| ==== 5. Earthquakes ==== | ==== 5. Seismic Vulnerability ==== |
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| === Past Earthquakes in the country which affected buildings of this type=== | === Past Earthquakes in the country which affected buildings of this type=== |
