Bridge body prestress tensioning method

The invention relates to a bridge body prestress tensioning method. The method comprises the step S5 of stably tensioning prestressed tendons in a graded mode, and specifically comprises the followingsteps that during tensioning, jacks at the two ends conduct oil feeding tensioning at the same time, the tensioning time is controlled, the tensioning control stress time from 0% to 100% is no less than 10 Min, every 5 PMa is one time of rising, and marks are made once every 10% of extending; and under 100% tension control stress, the time is longer than 2Min, oil feeding and oil returning of thejacks are slow and stable, and the oil returning time is not shorter than 2Min. The method has the beneficial effects that prestressed tendons are tensioned in a graded mode, stress concentration points caused by one-time tensioning of the prestressed tendons can be avoided, tensioning of the prestressed tendons is more uniform and stable, the tensioning time is controlled, the prestressed tendons can slowly adapt to the