Dewatering from excavation pit.

 

What to do if the excavation pit is waterlogged? Or what are the procedures you have to follow for dewatering the excavation pit? All these things seem to be minor, but actually not so. You have to take a long step to do it, and also have high thinking. You already know, how waterlogging occurs. Due to heavy rainfall or continuous rainfall, the area gets flooded and thus waterlogging occurs. But what happens, if your construction site or the excavation you have done for RE Wall gets waterlogged? So there are various steps you should have to do as follows: 

First of all, you cannot do dewatering directly if you see the water level rising up to the ground surface. You have to wait for some days for the sun to appear and to evaporate it. After that you can bring the water pump to dewater the excavation pit. Since the Sun cannot evaporate all the flooded water at once. It will need days to evaporate it or even a week. 
And if the sun appears one-or-two days and again the rainfall occurs, then it will be the same condition as before. So for these you have to wait till the flooded water lowers down/evaporates up. And when the water level is below the water table then ready for dewatering work. 

Second, for dewatering work, you have to do one step before. If any cement bags or sack bags are there, or left out anywhere throwing after use, you put some sand in it. So that you can put it them layer by layer or even barrier by barrier. So that you can dewater it part-by-part. Like this 

At last, you can go for dewatering work. It becomes easy and efficient. You find the way about the outlet, where the dewatering water would go/where to settle it. 

So all this process were followed in my site. The whole ground was heavily flooded and the water cannot pass through it. So with this flooded water the curing work was done on the panels and also it became use for washable concrete mixtures. But the excavation pit was dumped down like as river. And later when the water soaked or evaporated during sunny day, the dewatering work was on process.

So, like this process the work is going on and dewatering work is also on process. The amount of water fill there, will take minimum one week to clear it. So dewatering work will be going on continuously. In all construction process it's different. But here the process took long to dewater it. 

Also in building construction the process is different, in dam construction different process is used to dewater it, in construction of bridge & tunnels also. 

But here for RE Wall, as the excavation pit is too large and also the depth is more, so longer process it took to dewater it. You have to make a barrier with sack bags, make them part-by-part, then do dewatering etc. & etc.