Laserfiche WebLink
SEISMIC SLIDING <br /> The target factor of safety for seismic is 75% of the static value. Live loads are ignored in these analysis <br /> based on the basic premise that the probability of the maximum acceleration occuring at the exact same instant as <br /> the maximum live load is small. <br /> Details are only shown for sliding at the base of blocks, a check is made at the foundation level with the <br /> answer only shown. <br /> The vertical resisting forces is W 1 +W2 + Pav + Paev <br /> 2961 + 0 + 191 +48 SumVs = 3200 <br /> Resisting force = SumVs *tan(phi) + intercept x L FRe =2685ppf <br /> Driving force = Pa_h + Pae_h + Pif <br /> =712 +178 +246 FDr=1137ppf <br /> FOS = FRe/FDr FoS =2.36 <br /> SEISMIC OVERTURNING <br /> Overturning is rotation about the front toe of the wall. Eccentricity is also a check on overturning <br /> Resisting Moment= M1 + M2 + MPav+ MPaev <br /> 5574 + 0 + 538 + 144 + SumMrS =6256ftppf <br /> Driving Moment= MPah + MPaeh + MPif <br /> 1990 + 898 + 1240 SumMoS = 4127.82ftppf <br /> Factor of Safety= SumMrS/SumMoS FoS = 1.52 <br /> SEISMIC BEARING <br /> Bearing is the ability of the foundation to support the mass of the structure. <br /> Qult= c*Nc+ q*Nq + 0.5*gamma*(B')*Ng <br /> where: <br /> Nc= 50.59 <br /> Nq = 37.75 <br /> Ng = 56.31 <br /> c= 0.00psf <br /> q = 202.50psf <br /> Calculate Ultimate Bearing, Qult (seismic) Qult= 14437.17psf <br /> eccentricity (e) e =-0.065 <br /> Equivalent Footing Width, B' = L- 2e + Ivl pad B' =3ft <br /> Bearing Pressure = sumVs/B' sigma =933psf <br /> Factor of Safety for Bearing = Qult/Bearing FoS =15 <br /> Note: Calculations and quantities are for PRELIMINARY ANALYTICAL USE ONLY and MUST NOT be used for final <br /> n or construction without the independent review, verification, and approval by a qualified professional engineer. <br /> UltraWall 6.0.22298.930 14 <br />