::::::English Description::::::

CONBOX® is specifically developed for the analysis and design of post-tensioned and cast-in-place reinforced concrete box girder and slab bridges constructed on falsework. By incorporating both AASHTO Standard and LRFD specifications in one interface, CONBOX makes the transition to LRFD simple and efficient. The program accommodates span hinges and a variety of column shapes and fixity conditions.

Key Features

• Easy-to-use interface simplifies design. CONBOX makes the entry of project data convenient with an extremely user-friendly and efficient interface. Users specify bridge layout information such as alignment, span lengths, and cross-sections; pier, hinge and abutment locations; as well as superstructure-to-substructure connectivity. CONBOX can even import BDS input files to simplify workflow.

• Diverse code capabilities. Users may quickly toggle between AASHTO Standard and LRFD specifications, making the transition to LRFD simple and efficient. Post-tensioning losses can be computed according to AASHTO specification equations, lump-sum method or time-dependent models from either ACI-209, CEB-FIP, as well as LRFD models. Vehicle live loads are calculated using both AASHTO Standard and LRFD specifications.

• Powerful design features. Superstructure cross-sections may be user-defined or automatically generated by CONBOX. Cross-section options include transformed section properties, linear or parabolic variations along the length of the bridge for web transitions and flange thickening, and vertical or sloped exterior webs. CONBOX automatically inputs the top and bottom fillets between the flange and web junctions. Users may select from a variety of column shapes, specify linear or parabolic column variations, or specify their own pier properties. The number of columns is unlimited. Piers may be drop-cap or integral/monolithic.

• Automatic mild steel reinforcement calculations. CONBOX automatically computes the required mild steel reinforcement required at each check point. The user can define the nature of the reinforcement, and CONBOX will consider it when calculating ultimate shear and moment capacities. Ultimate moment/strength calculations can include effects due to time-dependent concrete compressive strength (f1c), mild reinforcing and post-tensioning.

• Comprehensive post-tensioning analysis. CONBOX allows for both linear and parabolic tendon layout. Users may define friction and wobble coefficients and input the anchor set. Post-tensioning jacking force may be entered manually or calculated as a percentage of the ultimate stress. Additional losses due to horizontal curvature are computed, as are tendon elongations.

• Full spectrum of load specifications. Users may specify uniform temperature loads (rise and fall), AASHTO temperature gradients, superimposed dead loads (FWS), and pedestrian loads. CONBOX automatically computes the self-weight of the structure. Moving live loads consist of AASHTO type vehicles (both lane and truck) and Cooper E-80 train loads. Users may also define concentrated or distributed custom loads.

• Structure analysis and model generation. CONBOX features 3D geometry with 2D plane frame FEM analysis. Side-sway effects are available as user-defined options, as are check points (POIs). CONBOX allows the user to define piers, hinges and abutment locations with each frame or for multiple frames. Pier support conditions at the bottom of the columns may also be defined (Pin, Fixed or Stiffness). Users may specify alignment information consisting of a combination of tangent, horizontal curves and spirals, and model semi-monolithic connections between the superstructure and substructure by specifying coupling and stiffness coefficients.

• Advanced design capabilities . CONBOX computes ultimate moment calculations based on AASHTO equations or strain compatibility. The capacity/demand ration and factor of safety is reported at each check point for stresses, ultimate moment, and shear length. Top and bottom flange stresses are checked, and required shear and moment reinforcement capacity is calculated. CONBOX also calculates the approximate level of post-tensioning force required to satisfy stress and the minimum compressive strength (f1c) necessary to satisfy AASHTO compressive stress checks. Detailed shear and moment calculations are also automatically computed.

• Automatic calculation of loads. CONBOX includes side-by-side LRFD permit vehicle effects, and users may specify unlimited load combinations and limit states. Analysis results include minimum and maximum effects for both individual and envelope effects.
   
• User-friendly report generation and export. CONBOX reports are viewable in both text and cross-section or elevation views or graphics. These reports can be exported to spreadsheets and to DXF files.