{{short description|X-shaped support substructure}} {{use dmy dates|date=August 2025}} [[File:Sujikai.jpg|thumb|right|Cross bracing between studs in a Japanese house]]
In construction, '''cross bracing''', also known as '''herringbone strutting, blocking, bridging, and dwanging''', are diagonal supports that intersect to reinforce structures.{{cn|date=August 2025}}
Cross bracing is usually seen with two diagonal supports placed in an X-shaped manner. Under lateral force (such as wind or seismic activity) one brace will be under tension while the other is being compressed. In steel construction, steel cables may be used due to their great resistance to tension (although they cannot take any load in compression). The common uses for cross bracing include bridge (side) supports, along with structural foundations. This method of construction maximizes the weight of the load a structure is able to support. It is a usual application when constructing earthquake-safe buildings.<ref>[http://www.conservationtech.com/FEMA-WEB/FEMA-subweb-EQ/02-02-EARTHQUAKE/1-BUILDINGS/MITIGATIONS/2-W2-cross_bracing.htm Reinforce Building With Cross Bracing], Earthquake Handbook, FEMA Hazard Mitigation Handbook Series, Federal Emergency Management Agency, 2002.</ref>
Cross bracing can be applied to any rectangular frame structure, such as chairs and bookshelves. Its rigidity for two-dimensional grid structures can be analyzed mathematically as an instance of the grid bracing problem.{{cn|date=August 2025}}
Cross bracing may employ full diagonals, or corner bracing<ref>{{cite report |last1=Tuomi |first1=Roger L. |last2=Gromala |first2=David S. |title=Racking Strength of Walls: Let-in Corner Bracing, Sheet Materials, and Effect of Loading Rate |series=USDA Forest Service Research Paper |date=1977 |number=FPL 301 |url=https://www.fpl.fs.fed.us/documnts/fplrp/fplrp301.pdf}}</ref> or knee bracing.
The idea of cross bracing is also applied to sport ram-air parachutes to improve their structural integrity.<ref>{{Cite web |title=Choosing a Canopy |url=https://www.uspa.org/about-uspa/uspa-news/choosing-a-canopy |access-date=2023-08-31 |website=www.uspa.org}}</ref>
==Mining tunnels== {{more citations needed|date=January 2021}} To add rigidity to the construction of mining tunnels, the cross-beam connecting between arches is also a type of cross brace. They are often tubular and modified on the ends with clips or apertures for screw fastening. They serve as a stiffening element for the stability of a design. This brace could also be an ordinary cross-section wooden cross-beam, or even a board.
Cross bracing can be seen in situations like flooring, where cross braces are put between floor joists in order to prevent movement. It is also commonly used for ship making in order to stand against heavy winds or extreme weather.
== Gallery == <gallery> File:Detail of underside of canopy east side showing cross bracing, rafters, and decking - Fort Hood, World War II Temporary Buildings, Cold Storage Building, Seventeenth Street, HABS TEX,50-KILL.V,1C-14.tif|Cross bracing between joists or rafters strengthens the members by preventing sideways deflection. File:DETAIL VIEW OF TOWER SHOWING CROSS BRACING AND RIVETS - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA HAER CAL,38-SANFRA,141-14.tif|Cross bracing on a bridge tower File:Diagonalenkreuz Aussichtsturm Buchenbronn18062019.png|Connection of diagonal stays (being stretched) at an observation tower File:Metal scaffolding at WP Welding 2.jpg|Part of scaffolding struts (being compressed) for construction work File:FlyingWires.JPG|Yellow struts and wire rope stays on a de Havilland Tiger Moth </gallery>
== See also == * Angle bracket (fastener), L-shaped structural fastener for fastening two objects together at an angle * Wind brace, diagonal brace to tie the rafters of a roof together and prevent racking
==References== {{commons category}} {{reflist}}
Category:Building engineering Category:Underground mining