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Engineering Analytics, Inc. <br />CLIENT: MGC JOB NO: 110617 PAGE: 1 of 2 <br />PROJECT: Spillway Drop Structure DATE: 11/30/2015 DATE CHECKED: 12/23/2015 <br />DETAIL: Water vs. Construction Moment COMPUTED BY: LCB CHECKED BY: LLM <br />Given: Retained Wall Height, H:=15 ft <br />Construction Load Height, Hconst:=2 ft <br />Water Level, W:= 12 ft <br />Unit Weight of Soil, y:=130 Ibs/ft3 <br />Unit Weight of Water, yw:=62.4 Ibs/ft3 <br />Stress Ratio, at rest, Ko := 0.5 <br />Strength Reduction Factor, 0:=0.75 <br />Compressive Strength of Concrete, f'c := 4500 psi <br />Earth Loading Factor of Safety, FSEarth:=1.6 <br />Live Loading Factor of Safety, FSLL:=1.6 <br />Find: If Constuction loading or ground water controls design <br />Solution: <br />Calculate bouyant unit weight <br />— 67.6 lbs <br />ft 3 <br />Calculate the maximum Moment at the Base of the Wall <br />2 / 2 \ 3 <br />MGW:=Ka•'y• (H 2w) •1 +w�+Ka••y•(H—w)•� —2)+K,, •'Yb' 6 <br />MGW=2.758.104 ft. lbs <br />ft <br />Mwater:=0.5.7'w•w2 • w =1.797.104 ft, lbs <br />3 ft <br />Mconst :=Ka''Y • Hconst • H • 2 =1.463.104 ft • lbs <br />2 ft <br />Msojjatrest:=0.5•Ko•y•H2 • 3 =3.656.104 ft - lb <br />f <br />Muconst FSEarth • Msozlatrest +FSLL' Mconst = 8.19.104 ft. lbs <br />ft <br />Muwater:=F''SEarth'MGW+FSLL•Mwater=7.288.104 ft• lbs <br />ft <br />Since Muwater < Muconst for wall heights less than 12 feet Construction loading controls <br />moment design <br />