Repair and reconstruction of engineering structures - Assessment and Refurbishment of Steel Structures - page 326

analysis it was obvious that the pipelines had been influenced by temperature effects. Due
to height and orientation of the pipelines, separation by symmetrical pushing was
impossible. Given this fact, a method of re-positioning the pipelines was agreed that
involved moving them from their present horizontal track into the required position using
a temporary device.
During the preparatory work the original bearing saddles at the locations where the
pipelines were to be separated and other saddles were modified for shifting in the
horizontal direction. While removing the original saddles, the horizontal and vertical
movements of the pipeline were monitored. Before the relocation of the pipeline began,
its position was secured against other movements and additional pulling devices were
fitted on the bridge (Figure 6.165). These consisted of a half-ring clamp (set on a pliable
base), draw bars and a movable binder. Where the pipeline was to be moved, a pliable
base was put under the steel half-ring clamp. After setting and fixing the base, the ring
clamp was fitted, to which the draw bars—threaded bars with a circular cross-section—
were connected. Gradually, the various elements of vertical brackets (Figure 6.166) of the
auxiliary device were inserted in the gaps between the flat profiles of the adjacent main
girder. An auxiliary horizontal bracket was connected to the vertical brackets to support
the hydraulic press. The free ends of the draw bars fitted with threads were anchored in
the movable binder. After completing the erection procedure, the hydraulic presses were
set for inducing the appropriate horizontal loadings.
Figure 6.165 The separating device