Under what situation shall engineers use jacking at one end only and from both ends in prestressing work?

During prestressing work toward one side, frictional losses will happen and the prestressing force diminishes along the length of tendon until arriving at the opposite side. These frictional losses incorporate the rubbing incited because of the change in curvature of tendon duct and furthermore the wobble impact because of deviation of duct arrangement from the centerline. In this way, the prestress force in the mid-span or at the opposite end will be enormously diminished in the event that the frictional loss is high. Subsequently, prestressing, from the two ends for a single span i.e., prestressing one-portion of complete tendons toward one side and the other half at the opposite end is done to empower an even dissemination and to give balance of prestress force along the structure.

Actually, stressing toward one side possibly has the expected favorable position of lower cost when contrasted and stressing from the two finishes. For various spans (for example two spans) with inconsistent range length, jacking is generally used toward the end of the more extended span in order to give a higher prestress power at the area of most extreme positive moment. Despite what might be expected, jacking from the end of the shorter span would be led if the negative moment at the middle support help controls the prestress force. Be that as it may, if the complete span length is adequately long, jacking from the two closures should to be thought of.