All reference beams and wires shall be independently
supported with supports firmly embedded in the ground at a
clear distance of not less than 8 ft (2.5 m) from the test pile or
pile group and as far as practical from the anchor piles or
cribbing. Reference beams shall be sufficiently stiff to support
the instrumentation such that excessive variations in readings
do not occur and should be cross connected to provide
additional rigidity. If steel reference beams are used, one end of
each beam shall be free to move horizontally as the beam
length changes with temperature variations.