In Substructure, you can manually input the loads for any load types. Bearing loads, column loads and cap loads are applied in pier global axis system. In case of a pier on a skew, the global X and Z-directions are not the same as the bridge transverse and longitudinal directions. As a result, you need to decompose longitudinal or transverse loads acting on the skewed bridge to those in the global X and Z direction of the pier and then use the decomposed loads in Substructure.

For multiple column pier and hammerhead pier, bearing/girder loads are applied at the top of the pier cap. Therefore, if you have a bearing load in Z-direction, this load will produce torsion in the cap. For integral pier, the girder loads are applied at the cap centerline. Cap and column loads, for all pier types are applied at the centerline of the cap and column, respectively.

When inputting the live load manually, please specify the loads without the live load impact factor. If the superstructure information is specified, the program computes the appropriate impact for the loads. However, you can change this option in the Analysis/Design parameters on the Analysis tab. Note that in AASHTO LRFD, different impact factors are applied to Truck and Lane loads. For manually input LRFD live loads, the program allows two sets of bearing loads. In this, the first set corresponds to the truck loads and the second set corresponds to the lane loads. For auto generated LRFD live loads, the program keeps two separate sets of loads also. In both manual or auto generated loads, the program appropriately applies impact factors when the analysis is performed. Further, note that when inputting loads manually, reduce the loads by the multi-presence factor and then input the loads.

Column loads are located with respect to the fixity point.

Any number of cap loads can also be specified. The location of loads is measured as a ratio with respect to the length of the cap. If a load is applied in the middle of the cap, its location should be a X/L = 0.5. For concentrated force in X or Z direction, Substructure also allows you to specify moment arm. Arm should be measured from the load application point to the cap centerline. In addition to concentrated loads, distributed loads or point moments can also be specified at any location along the length of the cap. In LRFD mode, Live Loads on cap may also be specified to be either lane loads or truck loads. Once specified correctly, program applies the corresponding impact factor during analysis.