1. Panel layout and erection sequence should have been analyzed more closely.
A cardboard model was recommended to facilitate the planning of casting and
handling each panel and visualizing the positioning of the crane to minimize its
movements. Using the model not only would increase productivity, but would
also improve communication throughout the operation by clearly displaying the
immediate and future work sequence.
2. Grout pads should have been used instead of the Teflon adjusting plates.
The Teflon adjusting plates were shifting during panel placement, making final
positioning of the panels more difficult and time consuming.
3. An air drill should have been used to reduce the time required for drilling
holes for the temporary bracing. The air compressor should also be used to expedite
the cleaning of these holes and the pickup points.
3. Modification to the rigging operation was necessary. The holes in the spreader
bar and location of the pickup points did not match on a variety of panels. It
was evident from the viewing of the tapes that lifting cables of varying lengths
were needed in rigging the different panels. Having fixed length cables resulted
in lifting some panels from fewer pickup points than specified in the design.
Reducing the number of pickup points could damage the panels, grade slab, and
equipment.
5. Use of a larger-size connecting angle, at the base of the panel, was recommended
to facilitate final alignment and welding of adjacent panels. This recommendation
became evident from a close-up view of the welding activities
using the hand-held camera.