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Guard Rail <br />Height of Guardrail h =42 in <br />Load on Guardrails P =200 lbs <br />Moment Required Mr = Ph =700 lb-ft <br />Wood Screw D =0.242 in <br />Specified Gravity G =0.5 DF <br />Withdrawal W = 2850G2D =172 lb/in <br />Embedment lem =4.75 in <br />Number of Screws in Tension n =3 <br />Tension Per screw T =819 lbs <br />Tension Force T = lem * W * n =3931 lbs <br />Compressive Pressure C⊥=625 psi <br />Area Req'd Areq = T / C⊥=6.3 in2 <br />Width Plate b =4.00 in <br />Depth of Compressive Area depth a = Areq / b =1.57 in <br />Depth of Tensile Force d =3 in <br />Moment Arm dm = d - a/2 =2.21 in <br />Moment Capacity M = T * dm =725 ft-lb <br />Demand Capacity Ratio DCR = M / Mr =0.97 <br />Requred Shear per screw Vr = P/2n =33.3 lbs <br />Tension per screw required Tr =1242 lbs <br />Resultant Force =1242 lbs <br />Adjusted Latera Design Z'=222 lbs NDS Table 12M OK <br />Resultant Angle =85.4 ° <br />=1288 lbs OK <br />α = TAN T <br />V <br />ZoN =WNp ZN <br />WNp cos α + ZNsin α <br />R =V + T <br />36