Edgefield, SC

New Orleans, LA

Note: No reason was given in the MHI/MHRA report for the exclusion of this test data at the New Orleans, LA test site, so we will assume, based on previous studies, that the 60-inch anchors could not be driven to their full-intended depth. Previous anchor testing by Pearson et al, 1991, disclosed that more than half of 48-inch anchors installed during their anchor study, could not be driven to their full-intended depth, even in soil that should have been favorable for this (sand).

Pearson et al. (1991)
The majority of 48-in anchors were unable to be driven to their full depth at the test site. Because of the type of soil, it was expected the soil be the most favorable for installing these types of anchors. This is very significant as anchors, which were not completely embedded carry very low load levels and exhibited large deformations at these low load levels.

Pearson et al. (1991)
In all cases, the only obstacle encountered was the frictional resistance of the sand acting on the auger disk. This condition was verified in several instances by digging up the anchor and examining the subsoil for rock, boulders, or other obstacles in the vicinity of the auger.

It is logical to assume that this problem does not improve with anchors of even greater length. The detrimental effects of anchors that are not fully embedded were discussed in more detail in the original report.

Mobile, AL

There was supplemental testing performed at the Baxley, GA and Edgefield, SC test sites for 30-inch and 36-inch anchors, using 17-inch stabilizer plates. In addition, during this subsequent testing, additional testing of both 30-inch and 36-inch anchors, with 12-inch stabilizer plates was also carried out, for comparison purposes. We will place the values for the subsequent testing of 30-inch and 36-inch anchors, with 12-inch stabilizer plates in tables below, and the results from the original testing from above, for the 30-inch and 36-inch anchors with 12-inch stabilizer plates, from the respective test sites. The subsequent testing shows the difficulty of saying that an anchor load capacity at one location is valid at another location. In short, the MHI/MHRA could not validate the original test results, at the same test sites.

Baxley, GA

Subsequent test results

Original test results

Note 1: Observe in Table 31 and 32, that the results of the subsequent testing of 30" anchors w/ 12" stabilizer plates at the Baxley, GA test site, yielded results that are lower than the original testing.

Edgefield, SC

Subsequent test results

Original test results

See Note 1, substitute Table "33", "34" for Table "31", "32", and "Edgefield, SC" for "Baxley, GA".

Baxley, GA

Subsequent test results

Original test results

Note 3: Observe in Table 35 and 36, that the results of the subsequent testing of 36" anchors w/ 12" stabilizer plates at the Baxley, GA test site, yielded results that are lower than the original testing.

Edgefield, SC

Subsequent test results

Original test results

See Note 3, substitute Table "37", "38" for Table "35", "36", and "Edgefield, SC" for "Baxley, GA"