The Non-Structural Components Should be Effectively Isolated from, or Properly Integrated with, the Basic Structural System

1.

The effect of the response of the structural system on the non-structural components is illustrated in Slides J81 and J82.

J81.  Inside view of a light, flexible, industrial building in Coalinga, California.  This warehouse building has a 100-ft span steel moment-resisting gabled frame which has cross-bracing in the roof but does not have longitudinal bracing in the sidewalls.

J82.  Outside view of the structure of Slide J81 after the 1983 Coalinga Earthquake.  While the light metal roof was intact, most of the corrugated asbestos cement siding suffered significant damage, emphasizing the need for proper attachment of non-structural components to the structural system.

2.

The effect of the non-structural components on the response of the structural system is illustrated in Slides J83-J88.  Analysis of building performance during earthquakes has shown that numerous building failures result from the fact that basic structural systems are designed neglecting the structural modifications introduced by the non-structural components, particularly by the addition of infills (partitions and walls) as illustrated in the following examples.

J83.  Medical Clinic in El Asnam, Algeria.  Close-up of column failure of this new 4-story reinforced concrete building induced by the response of the building to the 1980 El Asnam Earthquake [4].

J84.  Two-story reinforced concrete building, Managua, Nicaragua, damaged in the 1972 Managua Earthquake.  The slide shows a reinforced concrete column which was part of the structural system and which failed due to its shortening because of the effect of the masonry wall.  The masonry walls were considered as non-structural elements.

J85.  Mene Grande Building, Caracas, Venezuela, damaged in the 1967 Caracas Earthquake.  This 16-story reinforced concrete frame building has an H-shape in plan, and has tile walls in the four exterior ends of the building.  The design was conducted neglecting the interaction effects of these tile walls.  During the earthquake [24], there was not only considerable non-structural damage to the tile walls in the lower floors of the building, but also some spectacular failures on most of the first story corner columns as illustrated in this slide.  This emphasizes the importance of considering the interaction effects of the so called ‘non-structural’ components.  This building was repaired and retrofitted by adding shear walls and reinforcing the eight corner columns.

J86.  Capri Residencia Apartment Building, Caracas, Venezuela.  This 12-story reinforced concrete frame building with tile infilled exterior walls at its corners had a complete open first story for a parking area.  The building suffered considerable non-structural damage during the 1967 Venezuela Earthquake.  The tile walls and partitions of the lower stories shattered and had to be removed as is illustrated in this slide.  Note the very flexible structural system used in this building.

J87.  Damage to the Coral Apartment Building, Caracas, Venezuela, during the 1967 Venezuela Earthquake.  This building has a reinforced concrete frame as a structural system and infilled tile walls were used as exterior walls.  Note the long cantilevers.  Some of the tile walls in the second, third, and fourth stories exploded and fell down.  This explosion of the tile walls resulted also in severe damage to the beams and columns surrounding these walls. 

J88.  Plaza 1 Apartment Building, Caracas, Venezuela.  This is a 12-story reinforced concrete building with a penthouse and four levels of underground parking.  The building has split-level apartments, and its structural system is based on the use of reinforced concrete shear walls in both directions.  These shear walls give significant strength and stiffness to the building, allowing it to survive the 1967 Venezuela Earthquake without any structural or non-structural damage.