General

How can I apply transverse moving load?

Moving loads can be applied only in the gravity direction. Response for lateral loads due to centrifugal, wind and braking forces would need to be evaluated by applying equivalent static forces in lateral direction.

If absolutely necessary, you could try evaluating lateral moving loads in a separate model by the following manipulation:

• Create a copy of your model and rotate the entire model by 90 deg about global x axis. This rotation will align the lateral direction of the actual structure with the gravity direction in the SAP2000 model.
• Apply and evaluate moving loads. I would recommend using zero width lanes, as this would enable you to reuse lane definition from the original model.
• Manually (outside of SAP2000) superimpose the response from the lateral moving load analysis with the results obtained from the original model.

How can I change speed of the moving truck?

You can define the speed of a moving truck for step-by-step moving load analysis by entering the desired value of speed on the the "Multi Step Bridge Live Load Pattern Generation" form. Please note that you would first need to define a load pattern of type BRIDGE LIVE and then click modify bridge load button to access the "Multi Step Bridge Live Load Pattern Generation" form.

When we define a vehicle, which factor determines the direction of the movement of the vehicle? And how can we define a vehicle which can go in two directions?

For influence-based moving load analysis (load case type "Moving Load"), the vehicle is automatically moved in two directions. For step-by-step moving load analysis (load case type "Multi-step static"), you can specify the direction of vehicle movement as Forward or Backward on the "Multi Step Bridge Live Load Pattern Generation" form. To obtain multi step static response for a vehicle which can go in two directions, you could create an envelope of results for Forward and Backward motion of the vehicle.

Step-by-step

Influence-based

How does the program place the vehicle to calculate maximum effect? What algorithm is used?

Open Question

How exactly are the unit load distributed from from lane loading points to the model joints?

See Influence-based moving load analysis implementation

What are good numbers for Max. Lane Load Discretization Lengths Along Lane/Across lane? I mean the optimum condition for getting accurate results and being efficient.

Influence analysis can be quite time-consuming, so using the largest discretization size possible is recommended, especially for preliminary analyses. For overall superstructure and substructure behavior, discretization on the order of 1/10 of the span length and 1/2 of the lane width is usually sufficient. For more local effects, a smaller discretization may be needed. Plot the influence lines for a few representative quantities to help see what you should be using. Again, start with larger values so that you can run many early analyses, then refine the discretization for your final results.

Moving Load