Creative Rockeries
:: About Retaining Walls
The most important consideration in proper design and installation of retaining walls is that the retained material is attempting to move forward and down slope due to gravity. This creates a soil pressure behind the wall which depends on the angle of internal friction (phi) and the cohesive strength (c) of the retained material, as well as the direction and magnitude of movement the retaining structure undergoes. Lateral earth pressures are typically smallest at the top of the wall and increase toward the bottom. Earth pressures will push the wall forward or overturn it if not properly addressed. Also, any groundwater behind the wall that is not dissipated by a drainage system causes an additional horizontal hydraulic pressure on the wall.

 

A retaining wall is a structure that holds back soil or rock from a building, structure or area. Retaining walls prevent down slope movement or erosion and provide support for vertical or near-vertical grade changes. Retaining walls are generally made of masonry, stone, brick, concrete, vinyl, steel or timber. Once popular as an inexpensive retaining material, railroad ties have fallen out of favor due to environmental concerns. They also decompose over time.

Segmental retaining walls have gained favor over poured-in-place concrete walls or treated-timber walls. They are more economical, easier to install and more environmentally sound. Click on image to see gallery.

Terraced Rock Wall Using Basalt

Limestone Wall w/Steps & Alpine

  

Terraced Wall Using Basalt

Terraced Wall Using Basalt

  

10' Limestone Wall