Laboratory Testing

Laboratory Testing

Laboratory testing of Portadam, HESCO Bastion concertainer, RDFW, and sandbag

structures was conducted in a wave research basin at ERDC. The products were tested in a

controlled laboratory setting but under conditions that emulate real world flood fighting. The

structures were tested consecutively under identical conditions. Stringent construction, testing,

and removal protocols were developed for the laboratory. The protocol for the laboratory testing

included both performance parameters (hydrostatic testing, hydrodynamic testing with waves and

overtopping, and structural debris impact testing with a floating log) and laboratory setting

operational parameters (time, manpower, and equipment to construct and disassemble, suitability

for construction and disassembly by unskilled labor, fill requirements, ability to construct around

corners, disposal of fill material, damage, repair, and reusability).

The laboratory testing included the construction of skewed u-shaped structures. Each

structure had an approximate length of 85 ft. Due to the restrictive height of the research basin

walls, the height of each structure was limited to approximately 3 ft. Laboratory testing of the

structures was initiated in March 2004 and completed during August 2004. The sandbag structure

was tested first in the laboratory followed in order by the HESCO Bastion concertainer structure,

the RDFW structure, and finally, the Portadam structure.

Laboratory Testing Results

Tables 1 through 3 present a summary of pertinent laboratory testing results. The results show

that as expected, the sandbag structure took much longer (205.1 man-hours) to construct than the

other three structures. Only Portadam was removed in less time than required to remove the

sandbags, largely because all structures other than sandbags were largely reusable and required

care in their removal. The sandbag levee was the only structure to fail during any of the tests.

Table 1 gives a summary of man-hrs to construct and remove each structure. Details of the

construction are given in Table 4, and details of the removal are given in Table 5.

Each structure was allowed a maximum of three repairs at specified times during the testing

sequence, with each repair limited to a maximum of four man-hrs. In addition, one rebuild of the

structure was allowed. Only the sandbag levee required a rebuild. A summary of the man-hrs

required for repairs on each structure is given in Table 1, and details of each repair are given in

Table 6.

Seepage rates through the sandbag levee were very low during the one foot hydrostatic head

test because the sandbag levee is wide at the lower portion of the levee. Seepage rate increased

through the sandbags as the water elevation rose and the levee became narrower. Sandbags had a

particularly high "seepage" rate during dynamic tests with large waves because waves were able

to run up the sloped face of the levee and overtop the structure. Seepage rates during the static

head tests are given in Table 2.

Seepage rates for both RDFW and Portadam were generally much lower than for the sandbag

levee. Seepage rates for HESCO Bastion were considerably higher than sandbags, with most of

the seepage flowing through the junction between adjacent units. It was later determined that the

local HESCO office was not familiar with HESCO-recommended construction techniques for use

of the concertainers as a flood barrier that should significantly reduce the seepage between units.