Basalt is a dark-colored, fine-grained, igneous volcanic rock which is hard and dense. Individual mineral crystals are typically hard to see with the naked eye, although some kinds can contain larger crystals, or it may have holes that are empty (bubbles) or filled with other minerals.  Basalts are generally black or dark grey and polish well.  As a result, they are not easily scratched by metal objects. Basalt is often used for paving and ocasionally for wall construction.

SPBA_New Zealand_Bothara_1

Stone masonry building - walls are likely to be a mix of basalt and trachyte stones with variation in block size and colour (J. Bothara)

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A stone masonry building built in 1920s in Christchurch, New Zealand; exterior stonework is Halswell basalt with Oamaru limestone facings (W. Clark)

SPBA_New Zealand_ClarkW_2

A 19th century stone masonry construction: exterior wall wythe is fine grained grey Halswell basalt, with facing stones and base course of pinkish-brown Port Hills trachyte and string courses of speckled Hoon Hay basalt; Canterbury Provincial Buildings complex, Christchurch, New Zealand (W. Clark)

Structural steel or timber members are bolted together with steel bolts and nuts.

BOL_Canada_Brzev_1

Bolted connection of three steel members joined at a column, Canada *S. Brzev)

A more detailed occupancy description than the Building occupancy class - general

A framework of beams and columns in which inclined, often diagonal, structural members brace the building and provide strength and rigidity. The bracing can take a variety of forms. If diagonal members are stocky they resist both tension and compression forces. However if slender, they resist tension forces only. Usually, braced frame members are triangulated and meet at joints (similar to a vertical truss). Eccentrically Braced Frames are the exception - their inclined members are deliberately offset at joints in order to create ductile fuse regions in the steel beams. Braced Frames may or may not be infilled.

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A simplified drawing of a typical cross-braced frame structure (A. Charleson, Seismic Design for Architects, Architectural Press 2008, p. 64, Fig. 5.2).

LFBR_diagram_Charleson_1

Examples of different types of braced frames (A. Charleson, Seismic Design for Architects, Architectural Press 2008, p. 77, Fig. 5.23).

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Exterior braced frame as a retrofit scheme for a reinforced concrete building, Mexico (C. Scawthorn)

LFBR_USA_Brzev_2

Braced frame (Chevron braces), Seattle, USA (S. Brzev)

Braced Frame 1.JPG

Eccentrically braced steel frame under construction, New Zealand (A. Charleson)

LFBR_Canada_Brzev_1

Concentrically braced steel frame under construction, Canada (S. Brzev)

Braced Frame 2.JPG

 

Concentrically braced frame, India (A. Charleson)

Braced Frame 3.JPG

 

Braced frame, Iran (A. Charleson)

LFBR_Seattle_USA_BrzevS_1

 

 

LFBR_Seattle_USA_BrzevS_2

 

 

 

Steel braced frame, Seattle, USA (S. Brzev)

LFBR_University Hall_Berkeley_USA_1

Exterior steel braced frame as a retrofit solution, University Hall, University of Berkeley, California (S. Brzev)

LO_China_Brzev_1LO_China_Brzev_3

Birds Nest Stadium in Beijing, China has a 3-D braced frame structural system (S. Brzev)

The main overall type of occupancy