Table of Contents
FOUNDATION TREATMENT OF THE GRAVITY DAMS
- The foundation of the gravity dam should be hard, strong, durable and impervious.
- The imperviousness of the foundation is very important as uplift pressure depends greatly upon the seepage.
- Uplift pressure is increase when seepage is more.
- Hence to render the foundation water proof or impervious, it has to be suitably treat.
- All the loose overlying soil from the site is removed and solid rocky foundation is reach.
- The rocky foundation should also be excavated for some depth so that the proposed dam fits in the rock.
- This aspect will prevent the sliding of the dam over its foundation.
- A 3 cm thick layer of rich cement mortar should be laid on the excavated rocky foundation before concreting is done over it.
- All the faults, seams, cavernous rocks, crushed zones etc., should be either made good or removed from the foundation site.
- In order to prevent seepage through foundation, trenches may be excavated near heal of the dam and filled with cement concrete.
- Holes are drilled covering whole of the foundation and filled with cement grout.
- If the foundation is to be treated for large depths, the holes are also drilled for large depth.
- The holes are filled with cement grout in stages.
- Any other fault noticed in the foundation is rectified.