Volume of Limestone Pile

How can we calculate the volume of Limestone Pile by formula?
Can we calculate this by using the formula,
V = (L x W x H)/2 + (π r2)/3
where
L = Length of Pile
W = Width of Pile
H = Height of Pile
r = Radius of Cone
I have confusion using this formula. The L, W , H and r are not cleared to me.
Can anybody help me in this regard..?
Thanks in anticipation.