Purpose: Used to include a horizontal truss in box girder section properties.
--> Given in girder input
The equivalent area (in2 or mm2) of internal horizontal truss bracing to be included in section properties of a box girder. AHTRUSS represents the terms “2Adcos**2(phi(1))sin(phi(1))” in equation (2) on page 63 of the 1993 Guide Specifications for Curved Highways Bridges, and is used in this context for the equivalent thickness of the top flange closing plate for the noncomposite torsional constant “J”. In the absence of AHTRUSS data, the noncomposite torsional moment of inertia will be determined by assuming the top flange extends all the way across to close the box section, while the flexural moment of inertia will not use this assumption. (Also see VHTRUSS)
Note: ADTRUSS and ASTRUSS are the new approach to use for this information instead of AHTRUSS.