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<br />Normal construction procedures for concrete-block wall construction were <br />followed. Deflection gages (linear variable differential transducers, or <br />LVDT's) were installed against each of the two block walls to measure the <br />deflection of the walls. An independent bracing system was constructed at the <br />back of the wall to support the LVDT gages. <br />Block Wall 1, before and after the testing, is shown in Figure 18. The <br />front of the first wall was plastered, and a bulkhead was constructed in front <br />of it to contain water to be supplied from a fire hydrant. The second block <br />wall is shown in Figure 19. Block Wall 2 was used to test several flood pro- <br />tection systems. <br />Experimental tests <br />Typical deflection data for Block Wall 1 are presented in Figure 20. As <br />the water level was raised against the surfaced wall, the plaster was weakened <br />and was penetrated by the water; thereby reducing its effectiveness in <br />strengthening the wall against deflection. At a water depth of 3-1/2 ft the <br />block wall was cracked and leaking so badly that the trough could not be kept <br />filled with water from a fire hose connected to the fire hydrant. Water <br />flowed through the cracks faster than it could be put into the trough. Photo- <br />graphs of the leakage are shown in Figure 21. <br />The first test performed on Block Wall 2 was to partially fill (approxi- <br />mately 1-1/2 ft) the trough to determine the leakage through the block wall <br />(not treated or protected in any way). The leakage through the wall was <br />severe and the test was stopped. <br />The second test evaluated vinyl sheeting attached with a tubular seal and <br />also determined the deflection shape of the wall. The third test on Block <br />Wall 2 was to again test the effectiveness of the tubular seal. The test <br />results of the tubular seal and vinyl sheeting are presented in Part III. <br />Results <br />The safe water head on the block test walls is approximately the same as <br />that for a brick-veneer test wall; i.e., approximately 2 ft. By comparison, a <br />home has more wall support and can withstand about 3 ft of waterhead. <br /> <br />Analytical Computations <br /> <br />PlanninK of analytical computations <br />The analytical approach was to determine the feasibility of using the <br /> <br />13 <br />