Repair and reconstruction of engineering structures - Assessment and Refurbishment of Steel Structures - page 278

Figure 6.117 Comparison of
deformations in the tank shell along
the measuring plumb lines: (a) No.4,
(b) No.5
------------------ condition after damage
_._._._._._._. condition after filling the
tank with water
___________ condition after emptying
the tank (on completing the hydraulic
expansion procedure)
Ten plumb-lines measures were marked on one of the tank shells, but on the other
only nine, because of existing installations. Each plumb-line was provided with 18
measuring levels, three on every strake of plates. It was possible to carry out deformation
surveys three times, for each of the three stages distinguished above. The resulting
measurements, which demonstrate the efficiency of the hydraulic expansion technique,
are given for two selected measuring plumb-lines (Figure 6.117). The results for tank
after it had been cleared of water and subjected to hydraulic expansion were used to draw
a map of the deformations.
Apart from the shell's generating lines on which the surveys were made, the
deformation values for the remaining surface were determined making use of computer
interpolation (Figure 6.118). This map was used for assessing what repairs were