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B- LevelBrenneman Bull__ _d Design <br />200 200 _ 0.0033 <br />pm" f 60000 <br />0.59 <br />— 0.00151 <br />p 12(32.5) <br />3 - ft thick bulkhead does not meet minimum reinforcement requirement in ACI 318R - 92, Sec 10.5.1 <br />The bending stress design of #6 bars on 9 -in centers provides 0.59 in' steel area, which is <br />ft <br />0.59 <br />— 1.40 times the required tension reinforcement. This is not acceptable for the <br />0.42 <br />"Alternatively, area of reinforcement provided at each section, positive or negative shall be at <br />least one -third greater than that required by analysis" requirement (ACI 318R -92, Sec <br />10.5.2) because there is no negative compression reinforcement at the upstream face to meet <br />the requirement to prevent sudden collapse by concrete crushing of this 3 -foot thick <br />bulkhead. This alternative design is solely for thin slabs with both lower tension and upper <br />compression reinforcement. Therefore, the B- LevelBrenneman bulkhead must meet the the <br />requirement for "ratio of nonprestressed tension reinforcement" p - b d in ACI 318R- <br />92, Sec 10.5.1, as follows: <br />p,,,;,, = 0.0033 — A, — A, <br />b„,d 12(32.5) <br />A, = 0.0033(12)32.5 = 1.29 in <br />_ 1.27 — 0.0033 <br />P 12(32.5) <br />ft <br />Page 5 February 21, 1994 <br />required for ACI318R -92, Sec 10.5.1 <br />2 <br />#10 bars on 12 -in centers provides 1.27 ft of steel area. DESIGN CRITERIA <br />acceptable for ACI 318R - 92, Sec 10.5.1 <br />