A portion of an embankment having a uniform up-gradient 1 in 500 is circular with radius 1000 m of the centre line. It subtends 180° at the centre. If the height of the bank is 1 m at the lower end, and side slopes 2:1, the earth work involved ?
A. 26,000 m3
B. 26,500 m3
C. 27,000 m3
D. 27,500 m3