Well Foundations

Construction Aspects 

Well foundation is adopted when appreciable load is coming over soil like bridge piers etc. and when there is appreciable horizontal load like abutments, high mast etc. or when load is to be transmitted to rocky strata available at a shallow depth. You will be surprised to know that Tajmahal was built on well foundation. 

In river beds diversions or coffer dams are made to have a working platform for well sinking. These should be properly designed and strong enough to withstand the high flood level conditions. 

The alignment and location of the cutting edge and well kerbs should be carefully checked as these could not be corrected later. It should also be constructed with due 

care as it bears the brunt of the soil resistance during sinking. 

The sinking should be unliform. Records of sinking should he carefully noted. The scooping out of material from the bottom should be in an uniform manner as also the kentledge on the top of Ule well so that there is no tilting. Tilt and shift of the well shall be continuously recorded so that prompt remedial measures could be taken. 

Pneumatic well sinking should be done only by expert agencies. 

The level of the inside of the well should not be lowered to avoid sand blowing that may cause tilt of the well. 

After the well has reached the required depth, the bottom should be excavated to have the bottom plug. The tremie used for concreting shall be securely fixed with arrangement for horizontal movement. The tip of the tremie should be kept burried in concrete while concreting proceeds. Concreting of bottom should be done in one operation. 

The shuttering of top plug of wells, which are not filled up with soil, should be strong enough and they usually are not recovered.