QUESTION
Need inputs for increasing stability of a large open well in weathered laterite stone

Hello,

I have recently dug an open well in North Konkan - Raigad District. Raigad is not known for Laterite formation, however my area has very large laterite formation - upto 80 feet deep.

Top 8 ft is soil, then 16 feet of heavily weathered laterite + clay seams. So the well is 24 feet deep. The dimensions I have chosen (and dug) are large and unfortunately not circular : It is 45ft * 45ft for the first 8ft, then 30ft * 30ft for the next 8ft and then 20ft * 25ft for the last 8ft depth.

I had hoped that I will do lining only for the top 8ft where there is soil. However, now on seeing the semi-soft laterite formation, I am worried that it may not be strong enough.

The bottom section of the well has still not reached hard laterite so even if I try to start building a wall to line it, it will not have a firm foundation.

Another concern is the square cross section ... how can I give it some strength?

Any advice on how to improve structural stability of the well will be appreciated.

by
12 April 2013