Report #: 60

Report Date:

Country: SYRIA

Housing Type:

Housing Sub-Type:

Author(s): Adel Awad, Hwaija Bassam, Isreb Talal

Last Updated:

Regions Where Found: Buildings of this construction type can be found in the main cities of Syria like Damascus, Aleppo, Latakia, Homs, Hama, Deir-ez zor, Idleb, Al-Haskeh, Al-Raka, Al-Sweida, Dara, Tartus, Jableh, Qunitera etc. This type of housing construction is commonly found in urban areas.

Summary: These buildings are found in the main cities of Syria and represent modern construction practice followed in the last 50 years. The floor system is a two-way reinforced concrete slab, which spans between orthogonal sets of beams that transfer the load to the columns. The frames are designed to carry gravity loads only.

Length of time practiced: 25-60 years

Still Practiced: Yes

In practice as of:

Building Occupancy: Residential, 10-19 units

Typical number of stories: 3-5

Terrain-Flat: Typically

Terrain-Sloped: Occasionally

Comments:

Modern construction followed in the last 50 years.

There are from 6 to 12 units in each building.

Plan Shape: Rectangular, solid

Additional comments on plan shape:

Typical plan length (meters): 20

Typical plan width (meters): 16

Typical story height (meters): 3

Type of Structural System: Structural Concrete: Moment Resisting Frame: Designed for gravity loads only, with URM infill walls

Additional comments on structural system: Frames (columns, beams) carry gravity loading. We can assume that the frames (columns + beams) provide a partial strength and stiffness to control lateral displacements due to moderate earthquakes.

Gravity load-bearing & lateral load-resisting systems:

Typical wall densities in direction 1: 10-15%

Typical wall densities in direction 2: 10-15%

Additional comments on typical wall densities: The typical structural wall density is up to 20 %. Total wall area/plan area (for each floor) 10% to 15%.

Wall Openings: Area of openings /walls surface area = 20% for inner walls and 40% for outer walls.

Is it typical for buildings of this type to have common walls with adjacent buildings?: No

Modifications of buildings: There aren't a lot of modifications in this buildings yet.

Type of Foundation: Shallow Foundation: Reinforced concrete isolated footing

Additional comments on foundation:

Type of Floor System: Other floor system

Additional comments on floor system: Structural Concrete: cast in place solid slabs

Type of Roof System: Roof system, other

Additional comments on roof system: Structural Concrete: cast in place solid slabs

Additional comments section 2: When separated from adjacent buildings, the typical distance from a neighboring building is several meters.

Typical Plan Dimensions: Length varies from 12 to 20 meters, width varies from 12 to 16 meters. Typical Story Height: Story height ranges from 2.85 to 3.1 meters.

Who is involved with the design process?: EngineerArchitect

Roles of those involved in the design process: The owner of the land will hire an architect and a structural engineer to design the building.

Expertise of those involved in the design process: A structural engineer will have 5 years of education and more 5-10 years of experience. A construction engineer may have 5 years of education and less experience than the structural engineer. The designer may visit the construction site, at request.

Who typically builds this construction type?: Contractor

Roles of those involved in the building process: It is built by developers and sold to the people who live in this construction type.

Expertise of those involved in building process: A structural engineer will have 5 years of education and more 5-10 years of experience. A construction engineer may have 5 years of education and less experience than the structural engineer. The designer may visit the construction site, at request.

Construction process and phasing: For construction, they will use modern equipment. The construction of this type of housing takes place in a single phase. Typically, the building is originally designed for its final constructed size.

Construction issues

Is this construction type address by codes/standards?: Yes

Applicable codes or standards: Starting from 1997, the seismic design for buildings is mandatory as a law: Syrian code for earthquake resistant building (1995). Prior to 1997, seismic design was not applicable but the normal Syrian building code is used from 1972.

Process for building code enforcement: The building design must follow the 1995 Syrian code. In case of damage arbitration process may take place at the court of justice.

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:

Typical problems associated with this type of construction: The main problems are associated with the construction process e.g. mixing and transportation of concrete, and construction joints.

Who typically maintains buildings of this type?: Owner(s)Renter(s)

Additional comments on maintenance and building condition:

Unit construction cost: A unit construction may cost 100-200 USD/m# (USD =50 Syrian pound (SP), on market rate).

Labor requirements: One floor per month.

Additional comments section 3:

Damage patterns observed in past earthquakes for this construction type: Data about the earthquakes, starting from 18th century up to date, were taken from Ambraseys (1983). However, we have developed the estimate of the magnitude (M) and the maximum MMI intensity based on our findings and experience. Most of the buildings destroyed in the past earthquakes were of adobe and stone masonry, particularly in the urban areas.

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.

Vertical irregularities typically found in this construction type: Other

Horizontal irregularities typically found in this construction type: Other

Seismic deficiency in frames: Weak connections between the secondary and primary beams. No special transverse reinforcement at the critical region (joints).

Seismic deficiency in foundation: Reinforced concrete isolated footing without compression/tension ties.

Other seismic deficiencies: Poor quality of workmanship and materials. Development length not sufficient in compression and tension regions.

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

Additional comments on seismic strengthening provisions: Seismic strengthening has generally not been performed in Syria.

Has seismic strengthening described in the above table been performed?: No

Central Bureau of Statistics (1999), # Statistical Abstract 1999# , Damascus, 1999.

Ambraseys, N. N. (1993) #Earthquake Damage in the Arabic Region#, In : Assessment And Mitigation, UNESCO Publication , pp. 11-15.

United Nations Development Program (UNDP) (1999), # Urban Development Report 1999#, Oxford University Press, Ny.

Paulay, T and Priestley, M.J.N. (1992), # Seismic Design of Reinforced Concrete and Masonry Buildings #, John Wiley & Sons.

Syrian Engineers Order (1995), #Syrian Code for Earthquake Resistant Design and Construction of Buildings#.

Grunthal, G.et al .(1998), #European Macroseismic Scale 1998 , EMS-98#, European Seismological Commission (ESC), Luxembourg.