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15.4 Strucural Design Requirements DK BARBER RCE 21,110 date <br /> Seismic Coefficients for nonbuilding structures not similar to buildings pg 2 of 2 calcs 9/14/2018 <br /> table 15.4-2 select mechanically anchored flat bottom R= 3 <br /> 12.7.2 Effective Seismic Weight Wz=Total DL+Total LL(operating weight,assume tank's contents at 90%full) <br /> W,= 1,363 + 3,549 = 4,911 LBS <br /> 15.7.6 Ground-Supported Storage Tanks for Liquids <br /> 15.7.6.1 Smitankait¢hored.treatas;ri it#.-pefSection1$,4.2ci thisstandard Fundamental Period? eq.12.8-7 <br /> Total V=0.30 SDSW/p V=0.30 x 0.64 x 5,146 x 1.5= 1,414.5 Ta =Cth"n <br /> AST Only VAST=V=0.30 x 0.64 x 1,371 x 1.5= 392.4 from table 12.8-2, All other structural <br /> Contents Only V_tents V=0.30 x 0.64 x 3,775 x 1.5= 1,022.1 Ct= 0.02 (fromtable) systems <br /> x= 0.75 (from table) <br /> 15.4.2 Sm ti, nk t anchored Areat as"ti sd,"per Secticin 15;4.2.nf this,standard h= 5.25 (highest point,est.) <br /> n= 1 (single story) <br /> Ta = 0.069 ,as Ta is<0.06 s <br /> V=0.30 SDSWip eq.154-5 <br /> Overturning Moment apply V at AST cg <br /> where VAST= 392.4 <br /> where Vcontents 1022.1 <br /> 1414.5 =Total seismic base shear 3729/1482= <br /> height of CG., <br /> seismic MV D AST=VAST x 2.63 ft = 392.4 Ib x 2.63 ft= 1,033 Ib-ft <br /> seismic MV u=V­x 2.57 ft = 1,022.1 ib x 2.57 ft= 2,624 Ib-ft combined c.g. <br /> CI of CG,to Upping edge where Mtotal= 3,657 Ib-ft CG,= 2.52 <br /> resist MR=Wr x CGx = 4,911 Ib x 1.63 ft= 7,981 f.s.= 7981/3657= 2.18 <br /> Sliding without anchorage tipping about edge of AST Tipping: No problem <br /> Check if Sliding Compare frictional resistance vs.V although °h:� movement is blocked <br /> 15.7.6.1.5 V<Wt tan 30° V<5,146 x 0.577 V<2,969 max seismic base shear shall not exceed <br /> 1,414 vs 2,969 f.s.= 2969/1414= 2.10 <br /> Sliding: No problem <br /> Leak detection Barrier <br /> Concrete under slab <br /> What happens if horizontal movement during major earthquake? Won't tip over if AST slides westward, < r <br /> pavement is at same elevation(see photo). Metal wall prevents northward travel. '� 0z� <br /> Flotation: Empty Weight= 1,363 lbs Footprint(SF)= 17.06 Bouyant at 1.28 FT Inundation if AST Empty. <br /> Floating: No Problem <br /> -1o <br /> Flotation due to flooding is not a concern at this location,tank could float if water was 1.28 FT deep rn 00 <br /> and AST empty. Review of FEMA Map does not suggest flooding in less than 100 year event. <br /> Areas of Concern <br /> Emergency Pressure Relief Venting: Generally not required on non-flamable storage <br /> Frequency of Interstitial Void Monitoring <br /> Overfill Alarm if depth of wasteoil pumped into tank is greater than 90%Capacity <br />