Your back fill is having density of 1946 Kg/cum
it can be achieved when the moisture level in filling layer is at 8.10% by weight of soil.
Here, the values know to you are the volume of the back fill, which is 100 x 30 x 0.25 = 750 cum
So when you achieve a compaction to level of MDD, there will be 8.10% moisture level in it.
So considering the MDD, your filled soil weight is density x volume of fill
= 1946 x 750 = 1459500 Kg
The volume of water is at 8.1% of soil wet
= 1459500 x (8.1/100) = 118219.5 Kg or Liters of water.
Say my tanker capacity is 10,000 liters, to suffice the water demand of soil, I need to evenly pour 12 tankers on filled area, so that I will achieve OMC of 8.1% in total fill areas which will give me a compaction of more than 97% of my MDD.
