On the basis of the characters of HG - II myriametre rail welder and thetechnological request of rail gas pressure welding in the field, a ra.

This paper sums up the problems appearing easily in the tensioning construction of the long bundles of the steel strand in the long-span beam bridge,advances some solving measures,and probes into the control measures of developing the tension quality.

Numerical simulation analysis is made on a super-long steel structure by using ANSYS software to find out the inner forces of main components and the total longitudinal displacements under various temperatures,and three different design schemes are studied: expansion joints,non-expansion joints and slotted hole structure.

The model tests for the very long prestressing strands of Yeshan River Bridge on the West Section of Shanghai-Chengdu Expressway were made,the initial tensile force and load holding duration of the strands were studied and the research findings of the initial tensile force and load holding duration of the same type of the strands of several other bridges were provided.