Mexico

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Mexico is another country with a long record related to the application of confined masonry construction. Confined masonry is the most popular type of construction in Mexico, and it is widely used in the central part of the country.

This type of construction is practiced both in the form of non-engineered construction (mainly found in rural areas and suburbs of urban centres) and engineered buildings e.g. industrial facilities and formal housing developments built under the supervision of qualified professionals (Garcia, 2006).

Earthquake Performance
In general, low- to medium-rise confined masonry buildings (up to four or five storeys high) performed very well in the devastating 1985 Guerrero-Michoacan earthquake (magnitude 8.0), while many RC buildings were severely damaged or even collapsed in the same earthquake. A three-storey high office building with an irregular floor plan completely collapsed in the Ixtapa-Zihuatanejo region (Schultz, 1994). In the 1999 Tehuacan earthquake (magnitude 6.5), numerous unreinforced masonry buildings (mainly adobe construction) were affected by the earthquake, with over 14,000 units damaged and additional 2,500 units collapsed. Confined masonry buildings performed very well, however a few two-storey confined masonry houses were damaged due to inadequate wall strength and poor construction quality (EERI, 1999). In the 2003 Tecoman earthquake (magnitude 7.6), confined masonry buildings performed significantly better than unreinforced brick masonry and adobe buildings; majority of confined masonry buildings were undamaged or suffered only a minor damage. Cracks often formed between the masonry and the confining elements. Some instances of failure were observed when the number and arrangement of confining elements were inadequate(EERI, 2006b).

Confined masonry construction was introduced in Mexico City, Mexico in the 1940’s to control the wall cracking caused by large differential settlements under the soft soil conditions. Several years later, this system became popular in other areas of highest seismic hazard in Mexico due to its excellent earthquake performance (Meli and Alcocer, 2004).

In Mexico, six-storey high confined masonry buildings are not uncommon (Alcocer, 2006).  It is a common practice that low-rise confined masonry buildings  (up to two-storey high single-family construction) are  non-engineered, whereas engineers and architects are involved in  the design of taller apartment buildings.

Guidelines, Codes, and Standards

World Housing Encyclopedia Reports:
Report # 160 : Combined and Confined Masonry Construction

Publications

From Brzev, Svetlana. Earthquake-Resistant Confined Masonry Construction. 2nd ed. Kanpur: NICEE, 2007. Print.

Garcia, HJ. (2006). Personal Communication.

Schultz, A. E. (1994). Performance of Masonry Structures Extreme Lateral Loading Events. Masonry in the Americas, ACI Publication SP-l47, American Concrete Institute, Detroit, pp.21-55

EERI (1999). The Tehuacan, Mexico, Earthquake of June 15, 1999. EERI Special Earthquake Report. Newsletter. Earthquake Engineering Research Institute, California, September 1999.

EERI (2006b). The Tecomán, Mexico Earthquake January 21, 2003. An EERI and SMIS Learning from Earthquakes Reconnaissance Report, Technical Editors S.M. Alcocer and R.E. Klingner, Earthquake Engineering Research Institute, Oakland, California, March 2006.

Meli, R. and Alcocer, S. (2004). Implementation of Structural Earthquake-Disaster Mitigation Programs in Developing  Countries. Natural Hazards Review, ASCE,Vol.5, No.1, pp. 29-39.

Alcocer, S.M. (2006). Personal Communication.