Lapping Zone in Beam| Explained in Detail

Which bar is supposed to have crank for lapping bottom bars?

Suppose lap length is 50D,it is difficult to stagger the laps asper this rule

Sir if we do this then the lapping length will be too short

Sir... lapping is inner of column is that possible ,.lapping rod crosses column ,opp lap rod crosses that column...lap joint present in middle of that column,so beam failure occurs or not..?