Conclusion is made that modification of the top aperture chamfering of the roving tube and movement of the inserts POM downward can solve the said problems and stablized the spinning quality.

Experimental study of hole top strength about high strength reinforcement prestress concrete voided slabs;

The original ingate was enlarged by side cutting and roof cutting under the condition of filling behind wall by grouting, and then be supported and reinforced by the secondary support technology.