Alternative Support Systems for Cantilever - National Transportation ...

See Figure 5-12 for the graph of the applied load versus flexural rotation. gathered from LVDT’s
place on the base plate of the embedded pipe. The graph showing the torsional rotation of the
base plate for this test (Figure 5-12) shows significantly less rotation than the plate of the
previous test (Figure 5-6). This can be attributed to the fact that the LVDT was placed on the
base plate attached to the moment arm on the previous test and the LVDT was placed on the base
plate attached to the embedded pipe on this test. The moment arm base plate would feel more
rotation because of the bolt slippage occurring at the connection.
The graph of load versus flexural rotation was gathered from the LVDT’s placed on the
bottom of the base plate, front of shaft, and rear of shaft. The graph shows that the rotation
between the face of the shaft and the base plate was significantly greater than the rotation
between the face of the shaft and the rear of the shaft (See Figure 5-13). This can be attributed to
several things, including the steel pipe and base connection was less stiff than the concrete
pedestal as well as the concrete block was adequately designed as a fixed support, which would
have restrained the rotation at the base and created a deflection that could be adequately
described by an applied moment on a fixed cantilever.
As stated earlier, the LVDT’s gathered information from the base plate, the front of the
concrete pedestal and the rear of the concrete pedestal. The base plate’s torsional rotation
exceeded the rotations from the front of the concrete pedestal and the back of the concrete
pedestal (See Figure 5-14). This shows that the steel pipe and base plate was less stiff than the
concrete pedestal. The lack of considerable rotation in the rear of the concrete pedestal once
again shows that the concrete block connected to the concrete pedestal was adequately designed
as a fixed support.
70