MANAGEMENT OF OPEN WELLS UNDER QUICKSAND CONDITIONS

1.

Function

:

To prevent caving in open wells.

2.

Specification

:

The problem is due to the exit critical hydraulic gradient exceeding the shear strength of soil at the bed of the well. The sand flows like water.

3.

General information   

Open wells in quick sand areas is not feasible due to the caving in of side walls. Similarly, the bore wells also fail frequently due to the clogging of slots in casing pipes. In such places, this practice / management method will be of much help. Providing an inverted filter on the bed of well will control the sand flow. The thickness can be 30 to 40 cm. Smaller jellys of average diameter 20 mm may be placed immediately over the sand followed by bigger jellys.

4.

Cost

:

The cost of providing an inverted filter is about Rs. 200/- per m².