... 96 of 71 LRFD pre-stressed beam.mcd 7/1/2003 of 71 Section Diagram Section 70 60 50 beamxa , 40 xhxhn , xexhn , 30 20 10 40 20 20 40 beamxa , , xhxhn , , xexhn , 60 80 LRFD pre-stressed beam.mcd ... Deflection w_defl := DLnc + railwt ⋅ npar + median⋅ nmed beams + dwt LRFD pre-stressed beam.mcd 7/1/2003 Effective flange width (LRFD 4.6.2.6.1) (use the smaller of interior or exterior) Interior ... Inc h − yb Sb = 10543.065 St = 8907.755 2 ts LRFD pre-stressed beam.mcd 7/1/2003 11 of 71 Live Load Distribution Factors lanes := floor LRFD 3.6.1.1.1 - Number of design lanes roadway...