Estimating Sheet

# How to make retaining soil stable with Compaction and Geogrid

Construction Software

The objective of the Retaining wall block is to erect walls for holding or resisting the movement of the soil.

The maximum height these walls are constructed devoid of reinforcement is based on the following conditions :-

a. Size and mass of the block
b. Subsisting soil and retained slope conditions
c. Set back of the retaining wall

Retaining walls which are mainly dependent on their weight to sustain the soil behind them are known as gravity walls. In case of greater wall heights or specific site conditions like surcharges or a slope over the wall, a reinforced wall is built up.

Shears: Shear stands for the force employed while applying a pair of scissors.

a. Angle of Repose, b. Friction Angle

While reinforcing an Allan Block retaining wall, it is recommended to utilize geogrid.

Geogrid stands an adjustable mesh that is utilized to produce a reinforced coherent mass behind the retaining wall by making the soil stable.

The strength of the soil is primarily based on the friction angle it holds. The friction angle is defined as the shear strength of the soil. Shear belongs to the force that is applied while a pair of scissors is used.

### Also Read: Retaining Wall and its various features

In soil, the friction angle is the highest shear force among particles of soil since they attempt to pass each other.

When the soil is stacked on the ground it normally develops a conical shape. The steepness of the cone is directly associated with the friction angle of the soil. If there is a rough gravelly soil, it can be stacked into a steeper cone as compared to a soft finely grained soil.

Geogrid provides major strength to the soil cylinder and resists it from failing.

Materials Used: - 2 Tubes, 5 Screens (Circular Shaped), Sand (wet), Compaction Tool, Sand Scooper

The sand castle test selects two cylinders of soil and implies vertical force to check how the soil performs. The first cylinder is just compacted material. The second is also compacted material with the inclusion of mesh screens to simulate the application of geogrid reinforcement.

The geogrid reinforces the soil mass to empower it to resist much more force. It also facilitates the soil that is reinforced to function as one consistent gravity mass. For a simple gravity retaining wall, the forces from the soil being sustained should be held by the mass of the wall blocks.

When geogrid is applied with a retaining wall, the mass of the blocks and the extra mass of the reinforced soil allows resisting the pressures behind the wall. This combined mass facilitates constructing very tall walls at the time of using geogrid.