FP-96 English Version - Eastern Federal Lands Highway Division

Section 562562.04 Design Stresses, Loads, and Deflections. The allowable maximumdesign stresses and loads listed in this section are based on the use of undamaged,high-quality material. If lesser quality material is used, reduce the allowablestresses and loads. Do not exceed the following maximum stresses, loads,and deflections in the falsework design:(a) Timber.Compression perpendicular to the grain = 450 pounds per square inchCompression parallel to the grain (1) =480,000( L / d)2pounds per square inchNote: (1) Not to exceed 1,600 pounds per square inch.Where:L =d =Unsupported lengthLeast dimension of a square or rectangular column or the widthof a square of equivalent cross-sectional area for round columnsFlexural stress = 1,800 pounds per square inchNote: Reduced to 1,450 pounds per square inch for members with a nominaldepth of 8 inches or less.Horizontal shear = 190 pounds per square inchAxial tension = 1,200 pounds per square inchDeflection due to the mass of concrete may not exceed 1/500 of the spaneven if the deflection is compensated for by camber strips.Modulus of elasticity (E) for timber = 1.6 x 10 6 pounds per square inchMaximum axial loading on timber piles = 45 tonsDesign timber connections according to the stresses and loads allowed in theNational Design Specification for Wood Construction, as published by theNational Forest Products Association except:480