J51.  Damage to a 2-story masonry building in El Centro in the 1979 Imperial Valley Earthquake.  The upper parts of the brick walls fell down on the sidewalk due to lack of proper connection with the roof.  A building should be tied at the roof and floor levels continuously from exterior to exterior walls.

J52.  Chimney collapse of a modern house, 1983 Coalinga Earthquake.  Most of the chimneys were thrown down because of the lack of proper connections (straps) to the buildings.  A chimney must be tied to the frame of the building at the roof and floor levels.  This can be achieved easily and economically through the use of adequate steel straps.

J53.  Collapse of a split-level wooden home, 1971 San Fernando Earthquake.  Large numbers of these split-level homes suffered significant damage because of a lack of adequate ties between the two levels.  The upper level ripped away and crushed the lower garage walls which did not have adequate lateral bracing.

J54.  Alaska Sale and Service Building, Anchorage, Alaska, 1964 Alaska Earthquake.  This single-story building, 200 ft square in plan, was constructed using precast reinforced concrete hammerhead-tee column sections, precast reinforced concrete walls, and precast prestressed concrete roof tees.  All of these precast structural members were in place and connected at the time of the earthquake, but the peripheral collar beam had not been cast completely.  About half of these structural elements fell down because of inadequate connections, emphasizing the importance of properly tying together all of the building components [7, 8].

J55.  Collapse of one of the stair towers of the Medical Treatment and Care Unit, Olive View Hospital, 1971 San Fernando Earthquake.  This unit had 4 stair towers, and 3 of them collapsed by overturning.  These stair towers were separated form the main tower unit, but the separation was inadequate, resulting in the main unit pounding against the towers, which overturned after the failure of the poorly reinforced supporting columns in the lower story.

J56.  Collapsed canopy of the primary school near El Asnam, 1980 El Asnam Earthquake.  Each canopy was about 3.5 x 19.5 meters in plan, supported by a row of four centrally located cylindrical columns.  The failure of this canopy was triggered by the large overturning moment developed at the base of the column [4]. 

J57.  Damaged canopy of the primary school near El Asnam, 1980 El Asnam Earthquake.  Note the significant damage at the top and bottom of the columns and permanent distortion of the columns.  The canopies hammered against the facade of the adjacent buildings, producing damage in the facades.  These buildings restrained the lateral deformation of the canopy roof thereby preventing its collapse [4].

J58.  Retrofitting the hinge of an existing highway bridge by the use of restrainers, Oakland, California [19].