Description

The World Housing Encyclopedia (WHE) Report Database contains 130 reports on housing construction types in 43 seismically active countries. Each housing report is a detailed description of a housing type in a particular country. The description is prepared from a number of standard closed-ended questions and some narrative that have been provided by report authors. Each report has five major categories including architectural and structural features; Building Materials and Construction Process; Socio-economic Issues; Past Performance In Earthquakes, Seismic Features and Vulnerability; and Retrofit. All of the housing reports in this database have been contributed by volunteers. If you are interested in writing a housing report please contact the WHE Editorial Board.

About

The World Housing Encyclopedia (WHE) is a collection of resources related to housing construction practices in the seismically active areas of the world. The mission is to share experiences with different construction types and encourage the use of earthquake-resistant technologies worldwide. The technical activities of the WHE are steered by an international team of 22 professionals specializing in different aspects of seismic safety of buildings and structures. They bring relevant experience from 16 seismically active countries across the world. For more information about the World Housing Encyclopedia, visit http://www.world-housing.net/.

General Information

 

Report #:83
Building Type: Precast concrete panel apartment buildings
Country: Romania
Author(s): Maria Bostenaru Dan
Ilie Sandu
Last Updated:
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.
Summary:

This multi-family urban housing construction waspracticed in Romania between the ...

Length of time practiced: Less than 25 years
Still Practiced: No
In practice as of: 1990
Building Occupancy: Residential, 50+ units
Typical number of stories: 4-11
Terrain-Flat: Typically
Terrain-Sloped: 3
Comments: This construction was practiced between 1960 and 1990. In the Bucharest area,buildings of this type were initially built in 1959


 

Features

 

 

Plan Shape Rectangular, solid
Additional comments on plan shape
Typical plan length (meters) 25-125
Typical plan width (meters) 25-125
Typical story height (meters) 2.6
Type of Structural System Structural Concrete: Precast Concrete: Shear wall structure with precast wall panel structure
Additional comments on structural system This building type is characterized by a so-called "honeycomb" ("fagure" in Romanian) building plancharacteristic 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 abuilding 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 loadbearing 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-loadbearingstructures of lightweight block masonry construction. In some buildings of this construction type, precastconcrete wall panels are used as faade elements. The interior wall panels are of solid concreteconstruction - in this case, there is no need for a 3-layered panel section with thermal insulation in themiddle (typical for the faade wall panels).The load-bearing walls are laid in two principal directions, as illustrated in Figure 9. In general, there aretwo interior walls in the longitudinal direction and nine walls in the transverse direction; it should be notedthat 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 buildingrenovations carried out by owners.The main lateral load-resisting structure consists of 200 mm precast reinforced concrete wall panelssupported by RC slabs (walls in pre-1977 buildings are typically 140 mm thick). The wall panels form abox 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 thecolumns as "stiffening" elements at the exterior (as shown in Figure 10). According to NBS (1977), themechanical union of wall panels in the joints is achieved by means of splice bars welded to the transversereinforcement of adjacent panels. Longitudinal bars, used singly in vertical joints and in pairs in horizontaljoints, provide an added bearing area for the transfer of tension across the connections. The coupling ofthe floor panels is somewhat different, as illustrated in Figure 15. The top bars are splice welded whilethe bottom bars are bent up 90 degrees and lapped. This particular scheme gives greater continuity to thefloors at the supports than the lapped loop arrangement used in the high-rise building system. The wallpanels are mechanically coupled at their base, as illustrated in Figure 16, so that all vertical bars arecontinuous across the horizontal joints (it should be noted that in the case of the high-rise building panelconnections only the longitudinal bars of vertical joints are coupled).
Gravity load-bearing & lateral load-resisting systems
Typical wall densities in direction 1 5-10%
Typical wall densities in direction 2 5-10%
Additional comments on typical wall densities The typicalstructural wall density is 5% - 7% Wall density is larger in the transverse direction.
Wall Openings There are between 20 and 30 windows per floor. Each room has one window and one door, except forthe corridors (larger number of doors). Windows constitute around 25% of the exterior wall area, whereasdoors constitute less than 15% of the interior wall area.
Is it typical for buildings of this type to have common walls with adjacent buildings? No
Modifications of buildings Modifications in buildings of this type are not common.
Type of Foundation Shallow Foundation: Mat foundation
Additional comments on foundation In general, these buildings are supported by mat foundations. There are castin-situ basement walls.
Type of Floor System Other floor system
Additional comments on floor system Solid slabs (cast-in-place); Solid slabs (precast)
Type of Roof System Roof system, other
Additional comments on roof system Solid slabs (cast-in-place); Solid slabs (precast)
Additional comments section 2 Whenseparated from adjacent buildings, the typical distance from a neighboring building is 2.5 meters.

 

Building Materials and Construction Process

 

 

Description of Building Materials


Structural Element Building Material (s)Comment (s)
Wall/Frame Reinforced concrete:SteelSteel PC 52 - steel yieldstrength 350 MPa; Concrete:around 1970s, typicalconcrete strength was in therange of 25 MPa (cubestrength)Information onconcrete and steelproperties is inagreement with thereports after the1977 earthquake(e.g. NBS 1977)
Foundations
Floors
Roof
Other

Design Process


Who is involved with the design process? EngineerArchitectOther
Roles of those involved in the design process The building design was developed by "Design Institutes", which employ trained technical specialists,including engineers and architects.
Expertise of those involved in the design process The building design was developed by "Design Institutes", which employ trained technical specialists,including engineers and architects.

Construction Process


Who typically builds this construction type? Contractor
Roles of those involved in the building process Buildings of this type were financed by government housing funds and were built by construction companies.
Expertise of those involved in building process The construction was made by technical specialists employed by theconstruction companies using the specialized equipment. The construction was additionally supervised bya special unit called "State Inspection for Buildings".
Construction process and phasing The construction was performed using specialized equipment for prefabricated construction. The construction of thistype of housing takes place in a single phase. Typically, the building is originally designed for its final constructedsize. In some cases, new building blocks were built at the same location; however,these new blocks were built as completely new buildings with their own walls and foundations.
Construction issues

Building Codes and Standards


Is this construction type address by codes/standards? Yes
Applicable codes or standards This construction type is addressed by the codes/standards of the country. P-100-81. The year the firstcode/standard addressing this type of construction issued was 1981. The most recent code/standard addressing thisconstruction type issued was 1992.
Process for building code enforcement Information not available.

Building Permits and Development Control Rules


Are building permits required? Yes
Is this typically informal construction? No
Is this construction typically authorized as per development control rules? Yes
Additional comments on building permits and development control rules Building permits were required in the period when this construction was practiced. Building inspections wereperformed by the construction company staff and also by a special government department called "State ConstructionInspection."

Building Maintenance and Condition


Typical problems associated with this type of construction
Who typically maintains buildings of this type? Owner(s)
Additional comments on maintenance and building condition

Construction Economics


Unit construction cost The 1991 price was 2590 lei/m.sq. of the built area (176 USD/m/sq/.). Note that this is a real estate price(reflecting the value of an existing building) and not the cost of new construction (which is not available).
Labor requirements Information not available, as the construction company no longer exists.
Additional comments section 3

 

Socio-Economic Issues

 

 

Patterns of occupancy One family per housing unit.Each building typically has more than 100 housing unit(s). 150 units in each building. In general, there are 48 to 54housing units per building block. Each building block is centered around a staircase. There are usually between oneand five building blocks in a typical building complex.
Number of inhabitants in a typical building of this construction type during the day >20
Number of inhabitants in a typical building of this construction type during the evening/night >20
Additional comments on number of inhabitants
Economic level of inhabitants Middle-income class
Additional comments on economic level of inhabitants Ratio of housing unit price to annual income: 1:1 or better
Typical Source of Financing Other
Additional comments on financing Before 1990, the construction was financed by funds from the central government.After 1990 (post-communist period), individual apartments are owned by the inhabitants.
Type of Ownership Own outright
Additional comments on ownership
Is earthquake insurance for this construction type typically available? Yes
What does earthquake insurance typically cover/cost There is "Voluntary Complex Insurance of the Households of Physical Persons" throughS.C. ASIGURAREA ROMNEASCA - ASIROM S.A. (a public company).
Are premium discounts or higher coverages available for seismically strengthened buildings or new buildings built to incorporate seismically resistant features? No
Additional comments on premium discounts
Additional comments section 4 There is "Voluntary Complex Insurance of the Households of Physical Persons"through "S.C. ASIGURAREA ROMNEASCA - ASIROM S.A." (public company)

 

Earthquakes

 

 

Past Earthquakes in the country which affected buildings of this type


YearEarthquake Epicenter Richter Magnitude Maximum Intensity
1986Vrancea
1990Vrancea
78 (MMI)
6.77 (MMI)

Past Earthquakes


Damage patterns observed in past earthquakes for this construction type No damage to buildings of this type was observed in the 1986 and 1990earthquakes. In the 1977 earthquake (M 7.2 ), no significant damage was observed to other buildings ofsimilar construction.
Additional comments on earthquake damage patterns According to the reports on the 1977earthquake (Balan et al. 1982), somebuildings of this type experiencedcracking in the wall panel connectionarea, especially at the wall corner jointsand intersections, and wall-floorconnections. In some cases, those wereexisting cracks that were widened inthe 1977 earthquake. However, in thecity of Lasi (north of the epicentre), 45cracks developed in the walls especiallyabove the openings and around thestaircases in some 8-storey buildingsbuilt around 1960.

Structural and Architectural Features for Seismic Resistance


The main reference publication used in developing the statements used in this table is FEMA 310 “Handbook for the Seismic Evaluation of Buildings-A Pre-standard”, Federal Emergency Management Agency, Washington, D.C., 1998.

The total width of door and window openings in a wall is: For brick masonry construction in cement mortar : less than ½ of the distance between the adjacent cross walls; For adobe masonry, stone masonry and brick masonry in mud mortar: less than 1/3 of the distance between the adjacent cross walls; For precast concrete wall structures: less than 3/4 of the length of a perimeter wall.
Structural/Architectural Feature Statement Seismic Resistance
Lateral load pathThe structure contains a complete load path for seismic force effects from any horizontal direction that serves to transfer inertial forces from the building to the foundation.TRUE
Building Configuration-VerticalThe building is regular with regards to the elevation. (Specify in 5.4.1)TRUE
Building Configuration-HorizontalThe building is regular with regards to the plan. (Specify in 5.4.2)TRUE
Roof ConstructionThe roof diaphragm is considered to be rigid and it is expected that the roof structure will maintain its integrity, i.e. shape and form, during an earthquake of intensity expected in this area.TRUE
Floor ConstructionThe floor diaphragm(s) are considered to be rigid and it is expected that the floor structure(s) will maintain its integrity during an earthquake of intensity expected in this area.TRUE
Foundation PerformanceThere is no evidence of excessive foundation movement (e.g. settlement) that would affect the integrity or performance of the structure in an earthquake. TRUE
Wall and Frame Structures-RedundancyThe number of lines of walls or frames in each principal direction is greater than or equal to 2.TRUE
Wall ProportionsHeight-to-thickness ratio of the shear walls at each floor level is: Less than 25 (concrete walls); Less than 30 (reinforced masonry walls); Less than 13 (unreinforced masonry walls);TRUE
Foundation-Wall ConnectionVertical load-bearing elements (columns, walls) are attached to the foundations; concrete columns and walls are doweled into the foundation.TRUE
Wall-Roof ConnectionsExterior walls are anchored for out-of-plane seismic effects at each diaphragm level with metal anchors or straps. N/A
Wall OpeningsTRUE
Quality of Building MaterialsQuality of building materials is considered to be adequate per the requirements of national codes and standards (an estimate). TRUE
Quality of WorkmanshipQuality of workmanship (based on visual inspection of a few typical buildings) is considered to be good (per local construction standards).TRUE
MaintenanceBuildings of this type are generally well maintained and there are no visible signs of deterioration of building elements (concrete, steel, timber).TRUE

Additional comments on structural and architectural features for seismic resistance The buildings described in this report were designed in accordance with theP100-81 norm (the 1981 edition of the Romanian seismic standard).
Vertical irregularities typically found in this construction type Other
Horizontal irregularities typically found in this construction type Other
Seismic deficiency in walls
Earthquake-resilient features in walls - Large panel stiffness; redundancyprovided by several wall panels in bothdirections with frequent cross walls;regular and symmetric plan; goodquality of concrete construction.
Seismic deficiency in frames
Earthquake-resilient features in frame
Seismic deficiency in roof and floors
Earthquake resilient features in roof and floors #NAME?
Seismic deficiency in foundation
Earthquake-resilient features in foundation

Seismic Vulnerability Rating


For information about how seismic vulnerability ratings were selected see the Seismic Vulnerability Guidelines

High vulnerabilty Medium vulnerabilityLow vulnerability
ABCDEF
Seismic vulnerability class |- o -|

Additional comments section 5 Information on earthquake damage patterns is based on other buildings of similarconstruction that experienced the 1977 earthquake. The building described in this report was built afterthe 1977 earthquake.

Retrofit Information

 

 

Description of Seismic Strengthening Provisions


Structural Deficiency Seismic Strengthening

Additional comments on seismic strengthening provisions
Has seismic strengthening described in the above table been performed? Based on the good performance of buildings of similar construction in the 1977 earthquake, it isconsidered that retrofit is not required.
Was the work done as a mitigation effort on an undamaged building or as a repair following earthquake damages?
Was the construction inspected in the same manner as new construction?
Who performed the construction: a contractor or owner/user? Was an architect or engineer involved?
What has been the performance of retrofitted buildings of this type in subsequent earthquakes?
Additional comments section 6

 

References

Balan, S., Cristescu, V., and Cornea, I. (1982). Cutremurul de Pamnt din Romnia de la 4 Martie1977, The Academy of the Socialist Republic of Romania, Bucharest, Romania. (refer to Chapter VI.2.3."Behaviour of new residential buildings" by Mircea Lupan)


Smighielschi, S. (1990). Course notes on Building Construction, Architectural Institute "Ion Mincu",Bucharest, Romania.


NBS (1977). Observations on the Behavior of Buildings in the Romania Earthquake of March 4, 1977.U.S. Department of Commerce/National Bureau of Standards, NBS Special Publication 490, Washington,D.C., USA.


Authors



Name Title Affiliation Location Email
Maria Bostenaru Dan Dipl.-Ing. Urban and Landscape Department, on Mincu University of Architecture and Urbanism str. Academiei nr. 18-20, Bucharest 010014, ROMANIA Maria.Bostenaru-Dan@alumni.uni-karlsruhe.de
Ilie Sandu Ing. Bucharest, Romania

Reviewers


Name Title Affiliation Location Email
Svetlana N. Brzev Instructor Civil and Structural Engineering Technology, British Columbia Institute of Technology Burnaby BC V5G 3H2, CANADA sbrzev@bcit.ca