Page 447 - Advanced Design Examples of Seismic Retrofit of Structures
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Examples of Nonengineered Buildings Chapter  6 393

































             FIG. 6.2 An example comparing damage to a properly constructed “nonengineered” building and
             an improperly constructed “engineered” building. (A) An adobe building with slight damage.
             (B) A collapsed RC frame; the structural deficiencies include, but are not limited to, passing column
             bars outside the beam bars in the connection zone, wrongly-located split point in the column; very
             poor construction quality of split point in terms of bonding of concrete; and low-quality concrete.
             ((A) Photo taken by Mohammad Yekrangnia. (B) Permission from Dr. A.S. Moghadam.)



             This variety results in different behavioral characteristics, failure modes, and
             different performance levels during earthquakes. An example of two different
             failure modes caused from different construction details of adobe buildings in
             two different parts of the world is shown in Fig. 6.3. As a result, a particular
             retrofit scheme which suits a building type in one region may not be beneficial
             for the same structural system which is found in another part of the world; hence
             retrofit methods and especially details for each structural system is subjective to
             a specific details practiced in a particular region. Consequently, the contents of
             this chapter are presented in the form of major successful experiences from sev-
             eral countries that contributed to seismic retrofit of nonengineered buildings.
                Among the various structural types which are categorized as nonengineered
             buildings, adobe buildings constitute one of the most abundant and vulnerable
             construction types. Adobe as the main construction material of the early con-
             struction was available in the region and easily worked by local masons. Adobe
             has many promising features for construction in arid regions; it provides effec-
             tive thermal insulation, the clay-type soil from which adobe blocks are made is
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