Stone retaining wall contractor, RL Sanborn Masonry, is a located in Portland Maine and provides professional stone retaining wall construction, restoration and repair services throughout Cumberland County Maine. Many material options exist for stone retaining walls and are provided by local stone suppliers. You may choose from variations of stone, brick, concrete block or poured concrete. Stone retaining walls may be set with mortar or dry laid depending on preference.
reinforced with steel and installed below the frost line, to prevent shifting and cracking. Would you like a free retaining wall consultation and free retaining wall estimate? (click here) or Call (207)619-7473 |
What is a retaining wall? A retaining wall Is a structure that holds back soil or rock from a building, structure or area. Retaining walls prevent downslope movement or erosion and provide support For vertical or near-vertical grade changes. Cofferdams and bulkheads, structures that hold back water, are sometimes also considered retaining walls. 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. 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. The most important consideration in proper design and installation of retaining walls is that the retained material is attempting to move forward and downslope due to gravity. This creates lateral earth pressure behind the wall which depends on the angle of internal friction (phi) and the cohesive strength 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 hydrostatic pressure on the wall. As an example, the International Building Code requires retaining walls to be designed to ensure stability against overturning, sliding, excessive foundation pressure and water uplift; and that they be designed For a safety factor of 1.5 against lateral sliding and overturning |
Gravity Gravity walls depend on the weight of their mass (stone, concrete or other heavy material) to resist pressures from behind and will often have a slight 'batter' setback, to improve stability by leaning back into the retained soil. For short landscaping walls, they are often made from mortar less stone or segmental concrete units (masonry units). Dry-stacked gravity walls are somewhat flexible and do not require a rigid footing in frost areas. 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: ego synthetic or with pre cast facing; gabions (stacked steel wire baskets filled with rocks); crib walls (cells built up log cabin style from pre cast concrete or timber and filled with soil); or soil-nailed walls (soil reinforced in place with steel and concrete rods). |
Cantilevered Prior to the introduction of modern reinforced- soil gravity walls, cantilevered walls were the most common type of taller retaining wall. Cantilevered walls are made from a relatively thin stem of steel-reinforced, cast-in-place concrete or mortared masonry (often in the shape of an inverted T). These walls cantilever loads (like a beam) to a large, structural footing, converting horizontal pressures from behind the wall to vertical pressures on the ground below. Sometimes cantilevered walls are buttressed on the front, or include a counter fort on the back, to improve their stability against high loads. Buttresses are short wing walls at right angles to the main trend of the wall. These walls require rigid concrete footings below seasonal frost depth. This type of wall uses much less material than a traditional gravity wall. |
See also: Tieback (geo technical) This version of wall uses cables or other stays anchored in the rock or soil behind it. Usually driven into the material with boring, anchors are then expanded at the end of the cable, either by mechanical means or often by injecting pressurized concrete, which expands to form a bulb in the soil. Technically complex, this method is very useful where high loads are expected, or where the wall itself has to be slender and would otherwise be too weak. |
Types Of Retaining Walls |
What is masonry? Masonry is the building of structures from individual units laid in and bound together by mortar. The common materials of masonry construction are brick, stone such as marble, granite, travertine, limestone; concrete block, glass block, and tile. Masonry is generally a highly durable form of construction. However, the materials used, the quality of the mortar and workmanship, and the pattern the units are put in can strongly affect the durability of the overall masonry construction |
| RL Sanborn Masonry 2014 |
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| Maine Retaining Wall Contractor |
