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COVEY AUTO EXPRESS,INC. Stockton,CA DK BARBER RCE 21,110 1/23/2014 15.4 Strucural Design Requirements pg 2 of 3 Seismic Coefficients for nonbuilding structures not similar to buildings table 15.4-2 select Non-anchored"Ail-other" R= 1.5 12.71 Fjfcttim seismic weight W,=Total DL+Total LL(operating weight,assume tank's contents at 100%full) DL= 71 LL= 1,992 W,= 2,063 LBS 15.7.6 Ground-Supported Storage Tanks for Liquids 15.7.6.1 IF Small tank anchored treat as rigid per Section 15.4.2 of this standard Fundamental Period 7 eq.12.8-7 Total V=0.30$,Wfo V=0.30 x 0.61 x 2,063 x 1.5= 563 Ta =C,h'„ per 15.4.4 bldgs only AST Only VKr=V=0.30 x 0.61 x 71 x 1.5= 19 from table U-8-2 All other structural Contents Only V.m. i V=0.30 x 0.61 x 2,134 x 1.5= 544 C1= 0.02 systems x v 0.75 15.4.2 IF Small tank not anchored treat as rigid per Section 15.4.2 of this standard h= 4.5C where T Is less than 0.06 So, To = 0.062 ,as T.is<0.06 s 5m Is the design spectral response V-0.30 SgW6 eq.15.4-5 Overturning Moment apply Vat AST cg where Va,= 19 where V._,= 544 563 =Total seismic base shear ,ep,erq seismic Mvo as,=V,,, x 2.25 It - 19 x 2.25 - 43 seismic My u=V,,,a,x 2.25 h = 544 x 2.25 = 1,224 where Mexi,= 1,267 CG,= 2.25 resist Me=W,x CG, = 2,063 x 1.31 = 2,711 F.S. 2711/1267= 2.14 Sliding without anchorage Flat on finished concrete floor No problem Check If Sliding Compare frictional resistance vs.V although eastward and soutward movement is blocked 15.7.6.1.5 V<W,tan 306 V<2,053 x 0.577 V<1,302 max seismic base shear shall not exceed 563 vs 11190 fz. 1190/563= 2.11 No problem What happens if horizontal movement during major earthquake? Won't tip over if AST slides westward,additionally,may ha another tank floor is at same elevation(see photo). Exterior wall resticts travel. Flotation: Empty Weight= 71 lbs, Area(SF)= 13.1 Bouyant at 0.09 FT of water above tank button,if AST Empty. Tank on concrete shop floor Flotation due to flooding is not a concern at this location,tank could float if water was 0.09 FT deep and AST empty. Review of FEMA Map does not suggest flooding in less than 100 year event.