Steps For the Construction of Root Piles

In this article, we will discuss steps for the construction of root piles.

Root piles are extremely small-diameter piles commonly 60 mm to 135 mm. The length of the root piles commonly ranges from 4 m to 30 m.

The idea of a root pile was first presented by an Italian engineer named F. Lizzi. His prior concern behind root pile development was to do underpinning work. Nowadays, root piles are also employed for slope protection work, where a network of root piles is constructed to protect the slope. These are called reticulated root piles. Root piles are also employed in the correction of landslides.

Root piles should not be problematized with micro piles. In the case of micro piles, a steel pipe is employed whereas a single steel bar is employed in the case of root piles.

  A. Steps For the Construction of Root Piles  

1. Drilling of Hole

Drill a hole of about 50 mm in radius with or without a drill pipe. The radius of holes may be adjusted as per site soil needs or requirements. Drilling is accomplished by the rotary drilling method and is reached by the direct circulation of water or bentonite slurry. In the method of direct circulation, the cut pieces made due to the cutting action of the bit, come to the surface along with bentonite or water.

2. Placing Reinforcement Bar

After fulfillment of the drilling process to the essential depth, establish a single reinforcement bar of a diameter of about 15 mm or more. Then establish a tremie pipe inside the drill pipe. Tremie pipe is employed to recognize the mortar.

3. Filling of Mortar

Fill up the void with cement sand mortar prepared of 600 kg to 800 kg of cement for one cubic meter of sand. This type of mortar provides high strength. The mortar is positioned by a tremie pipe and is supplied from the bottom to the top. At any time during the period of the laying of mortar, the bottom end of the tremie pipe should be just inserted in the mortar being set.

4. Drill Pipe Removal & Pressure Application

The process of grouting is accomplished in different stages by splitting the grouted length into brief sections. This is accomplished to change the grout volume and injection pressure as per various soil requirements. At every stage, air pressure not surpassing 60 kg/m² is involved at the top of the drill pipe and tremies are slowly removed. Air pressure pushes it easy to remove the pipe and enhance pile soil contact.

5. Completion of Pile

After full removal of the drill pipe, release the air pressure and permit the mortar to mold.

Hope you get an idea of the steps for the construction of root piles.