Editing Retaining wall (section)

===Gravity===
[[File:Gravity Walls.jpg|thumb|Construction types of gravity retaining walls]]
[[File:Crib wall.JPG|thumb|An example of crib wall]]

Gravity walls depend on their mass (stone, concrete or other heavy material) to resist pressure from behind and may have a <!-- "batter" is NOT A TYPO -->'batter' setback to improve stability by leaning back toward the retained soil. For short landscaping walls, they are often made from [[Mortar (masonry)|mortar]]less stone or segmental concrete units (masonry units).<ref name="SEG">{{cite web| title = Segmental Retaining Walls| publisher = [[National Concrete Masonry Association]]| url = http://www.ncma.org/use/srw.html| access-date = 2008-03-24 |archive-url = https://web.archive.org/web/20080304073923/http://www.ncma.org/use/srw.html |archive-date = 2008-03-04}}</ref> Dry-stacked gravity walls are somewhat flexible and do not require a rigid footing. They can be built to a low height without additional materials being inserted, and have concrete added for strength and stability. 
<ref name="DRY">{{cite web| title = Dry Stack Retaining Walls| publisher = [[Australian Landscape Supplies]]| url = https://www.australianlandscapesupplies.com.au/collections/pentablock-modular-concrete-blocks| access-date = 2023-08-12 }}</ref>

Earlier in the 20th century, taller retaining walls were often gravity walls made from large masses of concrete or stone. Today, taller retaining walls are increasingly built as composite gravity walls such as: geosynthetics such as geocell cellular confinement earth retention  or with precast facing; [[gabion]]s (stacked steel wire baskets filled with rocks); crib walls (cells built up log cabin style from precast concrete or timber and filled with granular material).<ref name="soil-mechanics">{{cite book| last = Terzaghi| first = K.| author-link = Karl von Terzaghi| title = Theoretical Soil Mechanics| place = New York| publisher = John Wiley and Sons| year=1943}}</ref>