Retaining Wall and its various features

Retaining wall refers to a comparatively inflexible wall that can provide edgewise support to the soil mass to maintain the soil at various levels on the two sides.

This article mainly focuses on the following characteristics of retaining wall:

• Types
• Design
• Modes of Failure

Types of retaining wall: Generally the retaining wall is segregated into the following types -

Gravity Retaining Wall: These walls are formed on the basis of their weight for constancy. The walls are generally built up plain concrete or masonry. If your structure contains vast heights, these retaining walls may be quite expensive.

Semi-gravity Retaining Wall: The section size concerning a gravity retaining wall is minimized if the least amount of reinforcement is delivered close to the back face. Such walls are called semi-gravity walls.

Cantilever Retaining Wall: The main component of Cantilever retaining walls are reinforced cement concrete. The wall includes a lean stem as well as a base slab cast concretely. This type of wall is less expensive for the construction having a height of 6 to 8 m.

Counterfort Retaining Wall: Counterfort Retaining walls contain lean vertical slabs called counterforts, arranged over the vertical steam at constant intermissions. The counterforts bind the vertical stem through the base slab. In this way the vertical stem and the base slab stretch among counterfors. Thus the shear force and bending moments in the vertical stem and the base slab are decreased. The counterfort retaining walls are cost-effective for a height over 6 to 8 m.

How to make the Designs of retaining wall: Prior to starting of the real design, the soil parameters liable for manipulating the earth pressure and the bearing capacity of the soil should be assessed. The soil parameters consist of the unit weight of the soil, the angle of shearing resistance, the cohesion intercept and the angle of wall friction. The parameters help in finding out the lateral earth pressures and the bearing capacity of the soil. Once the earth pressures are obtained, the complete retaining walls should be analyzed for steadiness toward sliding, overturning, bearing capacity failure & tension.

Besides, the three types of failures like sliding, overturning and bearing failure, the following two modes also result in the failure of a retaining wall in case the soil underside is feeble.

Shallow Shear Failure: This type of failure happens along a cylindrical passing throughout the heel of the retaining wall. The failure occurs due to the unnecessary shear stresses beside the cylindrical surface within the soil mass. It is observed that the reason for safety alongside horizontal sliding is lesser as compared to the shallow shear failure. As a result, if the factor of safety alongside sliding is larger concerning 1.5, shallow shear failure may not happen.

Deep shear failure: It takes beside a cylindrical surface, once there exist a feeble layer of soil below the wall a depth regarding 1.5 times the height of the wall. The trial and error methods are used to detect the critical failure surface.

Ref.: www.civileblog.com/retaining-wall/