Design regulations#
Despite the existence of building design regulations in several African countries, relatively few include seismic provisions. Enforcement of existing design regulations is low in several countries. In addition, even in cases where seismic provisions do exist, they may not provide sufficient information for the typical building materials used within the country. Below is a review of the seismic design regulations.
Definitions of the design code levels and enforcement levels are summarized in the table below. Regional summaries for North Africa and Sub-Saharan Africa are provided in the subsections below. Countries not specified in the tables were not found to have any deliberate seismic design regulations.
Code level |
Enforcement level |
||
|---|---|---|---|
No code |
Codes that followed weak seismic provisions or no provisions at all (typically before the 1960’s). Some codes used allowable stresses and very low material strength values and considered predominantly the gravity loads. |
A |
Fully enforced (100%) |
Low code |
First generation of design regulations. These codes considered the seismic action by enforcing values of the seismic coefficient (typically called a lateral force coefficient). Structural design for these codes was typically based on material specific standards that used allowable stress design or a stress-block approach. Mostly introduced after the 1960s. |
B |
Mostly enforced (75%) |
Moderate code |
Second generation of design regulations. These codes include modern concepts of ultimate capacity and partial safety factors (limit state design) and/or with better detailing to improve global ductility. The seismic action was also accounted for in the design by enforcing values for the lateral force coefficient. It is noted that the distinction low and moderate code is often not straightforward and varying interpretations could be made by different engineers. Mostly introduced after the 1980s. |
C |
Partially enforced (50%) |
High code |
Third generation of design regulations. These codes refer to modern seismic design principles that account for capacity design and local ductility measures, similar to those available in Eurocode 8 (CEN 2004) for ductility class medium (DCM) (which is assumed to reflect the most frequently adopted ductility class). |
D |
Poorly enforced (25%) |
E |
Not enforced (0%) |
North Africa#
Unlike the other regions of Africa, North Africa has had numerous damaging earthquakes in recent history. Therefore, the relative level of risk awareness is higher and seismic design regulations are more common.
A summary table is presented below for countries within North Africa that have some evidence of deliberate seismic design regulations. Additional details for those countries are described below in this subsection. Countries without evidence of deliberate seismic design regulations are not described herein.
Low code |
Moderate code |
High code |
|||||||
|---|---|---|---|---|---|---|---|---|---|
Year |
Regulation |
Enforcement |
Year |
Regulation |
Enforcement |
Year |
Regulation |
Enforcement |
|
Algeria |
1981 |
RPA81, RPA81 Rev 83, RPA88, RPA99 |
D |
2003 |
RPA99 Rev 2003 |
C |
- |
- |
|
Egypt |
1989, 1993 |
ECP-1989, ECP-1993 |
D |
2003, 2008, 2012 |
ECP-2003, ECP201/ECP-2008, ECP-2012 |
C |
- |
- |
|
Libya |
1977 |
DSLS-1977 |
D |
- |
- |
- |
- |
||
Morocco |
1960, 1994 |
Agadir Standard, PS92 and BAEL 91 |
D |
2002, 2012 |
R.P.S. 2000, R.P.S. 2000 Version 2011 |
C |
- |
- |
|
Tunisia |
1992 |
BAEL 91 and CCBA 68/70 |
E |
- |
- |
- |
- |
Algeria#
In 1716, the Algiers earthquake killed an estimated 20,000. This prompted the first official seismic design regulations in Algeria in 1717 (Salhi and Daoudi 1994). However, these were a limited set of countermeasures. In the following decades, many more damaging earthquakes occurred, including the 1790 Oran earthquake that killed 3,000 and the 1825 Bilda earthquake that killed 7,000.
Design regulations were made more comprehensive in 1955 after the 1954 Chlef earthquake killed over 1,000 (Salhi and Daoudi 1994). Under French rule at the time, this event triggered the first generation of French seismic design provisions, which were solely applied to Algeria (Taleb 2010, Beauval and Bard 2021).
In 1980, the Al Asnam earthquake killed 5,000 in Algeria. The damage indicated that newly constructed buildings were not following basic seismic principles (Taleb 2010). Therefore, in 1981, the seismic design of buildings became mandatory (RPA81; Beauval and Bard 2021). These regulations were again revised in 1983 (RPA81 Rev 83). In 1988, special provisions were included for masonry structures (RPA88; Salhi and Daoudi 1994). A later revision in 1988 included a modification of the equivalent static method and promotion of the dynamic spectral method (RPA99; Taleb 2010).
In 2003, the Boumerdès-Zemmouri earthquake killed 2,266 in Algeria. The damage from this event highlighted that the existing codes were not being implemented, leading to another revision (RPA99 Rev 2003; Alaneme and Okotete 2018). These revisions included an update of the seismic zonation map, restrictions on the number of storeys, open space requirements to avoid soft storey issues, concrete strength requirements, and column size requirements (Taleb 2010).
There is concern that private builders (especially self-builders) that are responsible for approximately half the Algeria’s building stock rarely apply the existing regulations.
Egypt#
In 1752, an earthquake affecting Cairo killed 40,000 in Egypt. However, it wasn’t until 1989 that the first modern seismic design regulations were developed (ECP-1989). This iteration of the design code had notable limitations, as it neglected the influence of site conditions and applied a crude approach to estimate lateral seismic loading using an arbitrary percentge of the building’s weight (Abdel Raheem 2013).
A few years later, the 1992 Cairo earthquake killed 1,000. The seismic design regulations were revised to address deficiencies observed in 1993 (ECP-1993). This code improved the approach for estimating lateral loads for different structure types, but still contained significantly simplified assumptions (Abdel-Raheem et. al. 2010).
In 2003, the seismic design regulations were updated to account for response spectra, force reduction factors, and a soil factor (ECP-2003; El-Arab 2011, Alaneme and Okotete 2018). Additional revisions occurred in 2008 (ECP201/ECP-2008) and in 2012 (ECP-2012). Some detailing provisions considering the concept of ductility were introduced gradually in the revisions (Abdel Raheem 2013).
Libya#
In 1963, the Marj earthquake killed 300 in Libya. The first seismic design provisions were established in Libya in 1977 (DSLS-1977). However, these seismic provisions are not consistent with modern codes (Mohammed and Khatrush 2018).
Morocco#
In 1960, the Agadir earthquake killed 13,100, triggering the first seismic standard in Morocco (Agadir Standard; Cherif et. al. 2018).
In 1994, the Al Hoceima earthquake killed 2, inspiring constructive measures to protect buildings in the Rif region based on the French PS92 and BAEL 91 codes that were applied to Al Hoecima, Imzouren, and surrounding towns (Cherif et. al. 2018).
The first national seismic design code was applied in Morocco in 2002 (R.P.S. 2000; Cherif et. al. 2019). A few years later, 628 were killed in the 2004 Al Hoceima earthquake. The seismic design code was revised in in 2011 (R.P.S. 2000, Version 2011; Cherif et. al. 2019)
Tunisia#
Circa 856, an earthquake in Abbasid Caliphate (modern-day Tunisia) killed 45,000 (Ksentini and Romdhane 2014). This is the deadliest recorded earthquake on the African continent.
In 1758, the Tunis earthquake killed 3,000 in Tunisia.
Despite these damaging events, there is no official national seismic design code in Tunisia. Although there is no official code, some concrete buildings in Tunisia follow the French BAEL 91 (1992) or French CCBA 68 and 70 (1975) codes (Mansour et. al. 2013).
Sub-Saharan Africa#
Eastern and Southern Africa have notable seismicity, largely due to the East African Rift System (EARS), an active continental rift system that extends from northern Ethiopia and branches to the coast of Mozambique and into the Indian Ocean (to the east) and to central Mozambique (to the west). Western Africa is relatively low seismicity, although damaging earthquakes have occurred such as the 1983 MW6.3 Guinea earthquake that killed 443 and injured 1,436.
A summary table is presented below for countries within Sub-Saharan Africa that have some evidence of deliberate seismic design regulations. Additional details for those countries are described below in this subsection. Countries without evidence of deliberate seismic design regulations are not described herein.
Country |
Low code |
Moderate code |
High code |
||||||
|---|---|---|---|---|---|---|---|---|---|
Year |
Regulation |
Enforcement |
Year |
Regulation |
Enforcement |
Year |
Regulation |
Enforcement |
|
Cabo Verde |
2012 |
Technical Building Code |
E |
- |
- |
- |
- |
||
Ethiopia |
1980, 1983, 1995 |
CP1-78, ESCP1-83, EBCS 8: 1995 |
E |
2009, 2015 |
EBCS 8: 1995, ES8-2015 |
C |
- |
- |
|
Ghana |
BBRI 1990, BRRI 2010 |
E |
2018 |
GS 1207:2018 |
E |
- |
- |
||
Ivory Coast |
2019 |
Construction and Housing Code Law |
E |
- |
- |
- |
- |
||
Kenya |
1973 |
The Kenyan Code |
E |
- |
- |
- |
- |
||
Rwanda |
2009 |
Rwanda Regulations Manual |
E |
2019 |
Rwanda Building Code |
E |
- |
- |
|
South Africa |
1989, 1993 |
SABS 0160 |
E |
2009 |
SANS 10160 |
C |
- |
- |
|
Uganda |
- |
- |
2003 |
US 319:2003 |
D |
- |
- |
Cabo Verde#
The Technical Building Code (2012) includes some limited seismic provisions and references the Portuguese regulations in the event of situations not covered by the code.
Ethiopia#
Ethiopia first established seismic design regulations in 1980 (CP1-78; Worku 2014), which was revised for improved member design in 1983 (ESCP1-83; Alaneme and Okotete 2018). A 1995 revision (EBCS 8:1995) was based on Eurocode 8 (Worku 2014). In all three regulations, the design return period is clearly stated to be 100 years (rather than 475 years or similar; Kinde et. al. 2011, Worku 2014). Additionally, there is a lack of consideration of site effects or local faults and the earthquake catalogue only extends until 1990 (Ayele et. al. 2021).
In 2009, enforcement of codes was established (Kinde et. al. 2011). The current version of the code was established in 2015 (ES8-15; Alaneme and Okotete 2018). In this iteration, two levels of hazard are considered: the 95 year return period for limited damage and the 475 year return period for the ultimate limit state (Getachew et. al. 2020).
Ghana#
The first seismic design regulations in Ghana were established in 1990 (The Ghanaian Code, BRRI 1990; Alaneme and Okotete 2018).
An updated version of the code was established in 2010 (Seismic Design of Concrete Structures, BRRI 2010), however there were flaws in the seismic zonation and a lack of consideration of site effects (Worku 2014). An update to the Ghana Building Code was made in 2018.
Building collapses in Ghana independent of earthquake ground shaking signify a lack of enforcement (Asante and Sasu 2018).
Ivory Coast#
The Construction and Housing Code Law (Code de la Construction et de l’Habitat Loi n°2019‐576 du 26 juin 2019) referencces seismic hazards, but no detailed provisions exist.
Kenya#
Kenya was one of the first African countries to establish seismic design regulations in 1973, however there has been no revision since and the guidelines are not consistent with modern seismic provisions (Alaneme and Okotete 2018). Building collapses in Kenya independent of ground shaking (Worku 2014) signify a lack of enforcement of sufficient building design regulations.
A draft building code (2020) is actively under development.
Rwanda#
The 2009 Building Regulations Manual frin the Ministry of Infrastructure (MININFRA) references the British Standards (BS EN 1998, Eurocode 8) with a peak ground acceleration of 1.6 m/s^2 (Lubkowski et. al. 2014)
The 2019 Rwanda Building Code has performance checks for collapse prevention and limited damage in earthquakes. At this point, a seismic zonation or hazard map specific to Rwanda has not been identified for use in seismic design.
South Africa#
In South Africa, the first seismic design regulations were established in SABS 0160 (1989; Alaneme and Okotete 2018). Revisions were made in 1993. However, there was a lack of implementation of the seismic design guidelines (Wium 2009). In 2009, a major revision was made to improve seismic detailing and zonation as a part of SANS 10160 (Alaneme and Okotete 2018). SANS 10160 also accounts for site effects and return periods, whereby the 475 year return period is used as the design level earthquake (Worku 2014).
Uganda#
In 2003, Uganda issued provisions (US 319:2003), which takes into account ductility and seismic zonation (Alaneme and Okotete 2018). However, building collapses in Uganda independent of ground shaking (Worku 2014) signify a lack of enforcement of sufficient building design regulations.
Brief notes on other countries#
In some African countries, existing building design regulations make some reference to earthquakes but do not appear to include a seismic zonation map that would enable earthquake-resistant design. For example, Namibia often uses South African codes in theory but those lack a seismic zonation or hazard map specific to Namibia. Additionally, Mozambique references Portuguese codes that would lack a specific seismic zonation or hazard map for Mozambique. Nigeria has a national building code (Nigerian Building Code 2006), but it has not been adopted by local governments and also seems to lack a seismic zonation or hazard map.
References#
Abdel Raheem, Shehata E. “Evaluation of Egyptian code provisions for seismic design of moment-resisting-frame multi-story buildings.” International Journal of Advanced Structural Engineering 5, no. 1 (2013): 1-18. DOI: https://doi.org/10.1186/2008-6695-5-20
Abdel-Raheem, Khaled A., Shehata E. Abdel Raheem, Hosny M. Soghair, and Mahmoud H. Ahmed. “Evaluation of seismic performance of multistory buildings designed according to Egyptian code.” JES. Journal of Engineering Sciences 38, no. 2 (2010): 381-402. DOI: https://doi.org/10.1186/2008-6695-5-20
Alaneme, Kenneth Kanayo, and Eloho Anita Okotete. “Critical evaluation of seismic activities in Africa and curtailment policies–a review.” Geoenvironmental Disasters 5, no. 1 (2018): 1-17. DOI: https://doi.org/10.1186/s40677-018-0116-2
Asante, Lewis Abedi, and Alexander Sasu. “The challenge of reducing the incidence of building collapse in Ghana: Analyzing the perspectives of building inspectors in Kumasi.” Sage open 8, no. 2 (2018): 2158244018778109. DOI: https://doi.org/10.1177/2158244018778109
Ayele, Alemayehu, Kifle Woldearegay, and Matebie Meten. “A review on the multi-criteria seismic hazard analysis of Ethiopia: with implications of infrastructural development.” Geoenvironmental Disasters 8, no. 1 (2021): 1-22. DOI: https://doi.org/10.1186/s40677-020-00175-7
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Cherif, Seif-eddine, Mimoun Chourak, Mohamed Abed, and Abdelhalim Douiri. “Potential seismic damage assessment of residential buildings in Imzouren City (Northern Morocco).” Buildings 8, no. 12 (2018): 179. DOI: https://doi.org/10.3390/buildings8120179
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Salhi, Abdenour, and Mokhtar Daoudi. “Algeria.” In International Handbook of Earthquake Engineering, pp. 57-64. Springer, Boston, MA. (1994). DOI: https://doi.org/10.1007/978-1-4615-2069-6_5
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Taleb, Rafik. History of Algerian Seismic Regulations and Comparison with Japanese and European Seismic design codes. (2010). Available at: https://www.researchgate.net/publication/319088182_History_of_Algerian_Seismic_Regulations_and_Comparison_with_Japanese_and_European_Seismic_design_codes
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